Zero To Finals - Obstetrics Flashcards
Trimesters
Trimesters
1. The first trimester is from the start of pregnancy until 12 weeks gestation.
2. The second trimester is from 13 weeks until 26 weeks gestation.
3. The third trimester is from 27 weeks gestation until birth.
It is worth noting that fetal movements start from around 20 weeks gestation, and continue until birth.
Importance of folate in pregnancy
Folate
Important for cell division and growth
Give 400micrograms daily during preconception and 1st trimester
Higher risk pregnancies get folic acid 5mg OD:
• Taking anti-epileptics
• Have a neural tube defect in mother/father
• Mothered a previous child with a neural tube defect
• DM
• Sickle cell disease
Combined test for Down syndrome
Combined Test
The combined test is the first line and the most accurate screening test.
It is performed between 11 and 14 weeks gestation and involves combining results from ultrasound and maternal blood tests.
1. Ultrasound measures nuchal translucency, which is the thickness of the back of the neck of the fetus.
a. Down’s syndrome is one cause of a nuchal thickness greater than 6mm.
2. Maternal blood tests:
○ Beta‑human chorionic gonadotrophin (beta-HCG) – a higher result indicates a greater risk
○ Pregnancy‑associated plasma protein‑A (PAPPA) – a lower result indicates a greater risk
Antenatal testing for Down syndrome
§ The screening tests provide a risk score for the fetus having Down’s syndrome.
§ When the risk of Down’s is greater than 1 in 150 (occurs in around 5% of tested women), the woman is offered amniocentesis or chorionic villus sampling.
Non invasive pre natal testing
Non-Invasive Prenatal Testing
• Non-invasive prenatal testing (NIPT) is a relatively new test for detecting abnormalities in the fetus during pregnancy.
• It involves a simple blood test from the mother.
• The blood will contain fragments of DNA, some of which will come from the placental tissue and represent the fetal DNA.
• These fragments can be analysed to detect conditions such as Down’s.
• NIPT is not a definitive test, but it does give a very good indication of whether the fetus is affected.
• NIPT is gradually being rolled out in the NHS as an alternative to invasive testing (CVS and amniocentesis) for women that have a higher than 1 in 150 risk of Down’s syndrome.
Hypothyroidism in pregnancy
Hypothyroidism in Pregnancy
• Untreated or under-treated hypothyroidism in pregnancy can lead to several adverse pregnancy outcomes, including miscarriage, anaemia, small for gestational age and pre-eclampsia.
• Hypothyroidism is treated with levothyroxine (T4).
• Levothyroxine can cross the placenta and provide thyroid hormone to the developing fetus.
• The levothyroxine dose needs to be increased during pregnancy, usually by at least 25 – 50 mcg (30 – 50%).
• Treatment is titrated based on the TSH level, aiming for a low-normal TSH level.
Hypertension in pregnancy
Hypertension
Women with existing hypertension may need changes to their medications.
Medications that should be stopped as they may cause congenital abnormalities:
• ACE inhibitors (e.g. ramipril)
• Angiotensin receptor blockers (e.g. losartan)
• Thiazide and thiazide-like diuretics (e.g. indapamide)
Medications that are not known to be harmful:
• Labetalol (a beta-blocker – although other beta-blockers may have adverse effects)
• Calcium channel blockers (e.g. nifedipine)
• Methyldopa
Target BP if hypertensive before pregnancy is 135/85
Sickle cell disease in pregnancy
Sickle Cell Disease
• Should take aspirin from 12 weeks of pregnancy
• Screen for trait in mother and if present check the father
HIV in pregnancy
HIV
• Start highly active antiretroviral treatment at 24 weeks
• Screen for hep B/C
• Usually delivered by caesarean to reduce vertical transmission
○ Unless have very low CD4 viral load
• Avoid breast feeding
Epilepsy in pregnancy
Epilepsy in Pregnancy
§ Women with epilepsy should take folic acid 5mg daily from before conception to reduce the risk of neural tube defects.
§ Pregnancy may worsen seizure control due to the additional stress, lack of sleep, hormonal changes and altered medication regimes.
§ Seizures are not known to be harmful to the pregnancy, other than the risk of physical injury.
§ Ideally, epilepsy should be controlled with a single anti-epileptic drug before becoming pregnant.
Regarding anti-epileptic drugs:
§ Levetiracetam, lamotrigine and carbamazepine are the safer anti-epileptic medication in pregnancy
Rheumatoid arthritis in pregnancy
Rheumatoid Arthritis
□ Rheumatoid arthritis is an autoimmune condition that causes chronic inflammation of the synovial lining of the joints, tendon sheaths and bursa.
□ It is an inflammatory arthritis.
□ It is treated with disease-modifying anti-rheumatic drugs (DMARDs).
□ Ideally, rheumatoid arthritis should be well controlled for at least three months before becoming pregnant.
□ Often the symptoms of rheumatoid arthritis will improve during pregnancy, and may flare up after delivery.
The treatment regime may need to be altered by a specialist rheumatologist before and during pregnancy:
□ Methotrexate is contraindicated, and is teratogenic, causing miscarriage and congenital abnormalities
□ Hydroxychloroquine is considered safe during pregnancy and is often the first-line choice
□ Sulfasalazine is considered safe during pregnancy
□ Corticosteroids may be used during flare-ups
NSAID’s in pregnancy
Non-Steroidal Anti-Inflammatory Drugs
E.g. ibuprofen and naproxen.
• They work by blocking prostaglandins. • Prostaglandins are important in maintaining the ductus arteriosus in the fetus and neonate. • Prostaglandins also soften the cervix and stimulate uterine contractions at the time of delivery. • NSAIDS are generally avoided in pregnancy unless really necessary (e.g. in rheumatoid arthritis). • They are particularly avoided in the third trimester, as they can cause premature closure of the ductus arteriosus in the fetus. • They can also delay labour.
Beta blockers in pregnancy
Beta-Blockers
Beta-blockers are commonly used for hypertension, cardiac conditions and migraine.
Labetalol is the most frequently used beta-blocker in pregnancy, and is first-line for high blood pressure caused by pre-eclampsia.
Beta-blockers can cause:
• Fetal growth restriction
• Hypoglycaemia in the neonate
• Bradycardia in the neonate
ACE Inhibitors and ARBs in pregnancy
ACE Inhibitors and Angiotensin II Receptor Blockers
○ Medications that block the renin-angiotensin system (ACE inhibitors and ARBs) can cross the placenta and enter the fetus.
○ In the fetus, they mainly affect the kidneys, and reduce the production of urine (and therefore amniotic fluid).
○ The other notably effect is hypocalvaria, which is an incomplete formation of the skull bones.
ACE inhibitors and ARBs, when used in pregnancy, can cause:
○ Oligohydramnios (reduced amniotic fluid)
○ Miscarriage or fetal death
○ Hypocalvaria (incomplete formation of the skull bones)
○ Renal failure in the neonate
○ Hypotension in the neonate
Opiate use in pregnancy
Opiates
• The use of opiates during pregnancy can cause withdrawal symptoms in the neonate after birth.
• This is called neonatal abstinence syndrome (NAS).
• NAS presents between 3 – 72 hours after birth with irritability, tachypnoea (fast breathing), high temperatures and poor feeding.
Antibiotic use in pregnancy
Antibiotics
1st line = penicillins + cephalosporins
Avoid tetracyclines in 2nd + 3rd trimester - risk to bone and tooth development
Avoid nitrofurantoin in 3rd trimester - risk of haemolytic anaemia in newborn
Warfarin and pregnancy
Warfarin
Warfarin may be used in younger patients with recurrent venous thrombosis, atrial fibrillation or metallic mechanical heart valves.
It crosses the placenta and is considered teratogenic in pregnancy, therefore it is avoided in pregnant women.
Warfarin can cause:
§ Fetal loss
§ Congenital malformations, particularly craniofacial problems
§ Bleeding during pregnancy, postpartum haemorrhage, fetal haemorrhage and intracranial bleeding
Lithium in pregnancy
Lithium
Lithium is used as a mood stabilising medication for patients with bipolar disorder, mania and recurrent depression.
It is avoided in pregnant women or those planning pregnancy unless other options (i.e. antipsychotics) have failed.
• Lithium is particularly avoided in the first trimester, as this is linked with congenital cardiac abnormalities. ○ In particular, it is associated with Ebstein’s anomaly, where the tricuspid valve is set lower on the right side of the heart (towards the apex), causing a bigger right atrium and a smaller right ventricle. • When lithium is used, levels need to be monitored closely (NICE says every four weeks, then weekly from 36 weeks). • Lithium also enters breast milk and is toxic to the infant, so should be avoided in breastfeeding.
SSRI’s in pregnancy
Selective Serotonin Reuptake Inhibitors
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly used antidepressants in pregnancy.
□ SSRIs can cross the placenta into the fetus.
□ The risks need to be balanced against the benefits of treatment.
□ The risks associated with untreated depression can be very significant.
Women need to be aware of the potential risks of SSRIs in pregnancy:
□ First-trimester use has a link with congenital heart defects
□ First-trimester use of paroxetine has a stronger link with congenital malformations
□ Third-trimester use has a link with persistent pulmonary hypertension in the neonate
□ Neonates can experience withdrawal symptoms, usually only mild and not requiring medical management
Roaccutane in pregnancy
Isotretinoin (Roaccutane)
Isotretinoin is a retinoid medication (relating to vitamin A) that is used to treat severe acne.
It should be prescribed and monitored by a specialist dermatologist.
• Isotretinoin is highly teratogenic, causing miscarriage and congenital defects. • Women need very reliable contraception before, during and for one month after taking isotretinoin.
Rubella in pregnancy
Rubella
• Rubella is also known as German measles.
• Congenital rubella syndrome is caused by maternal infection with the rubella virus during the first 20 weeks of pregnancy.
• The risk is highest before ten weeks gestation.
• Women planning to become pregnant should ensure they have had the MMR vaccine.
○ When in doubt, they can be tested for rubella immunity.
○ If they do not have antibodies to rubella, they can be vaccinated with two doses of the MMR, three months apart.
• Pregnant women should not receive the MMR vaccination, as this is a live vaccine.
○ Non-immune women should be offered the vaccine after giving birth.
The features of congenital rubella syndrome to be aware of are:
• Congenital deafness
• Congenital cataracts
• Congenital heart disease (PDA and pulmonary stenosis)
• Learning disability
Chicken pox in pregnancy
Chickenpox
Chickenpox is caused by the varicella zoster virus (VZV).
It is dangerous in pregnancy because it can lead to:
○ More severe cases in the mother, such as varicella pneumonitis, hepatitis or encephalitis
○ Fetal varicella syndrome
○ Severe neonatal varicella infection (if infected around delivery)
Mothers that have previously had chickenpox are immune and safe.
○ When in doubt, IgG levels for VZV can be tested. A positive IgG for VZV indicates immunity.
○ Women that are not immune to varicella may be offered the varicella vaccine before or after pregnancy.
Exposure to chickenpox in pregnancy:
○ When the pregnant woman has previously had chickenpox, they are safe
○ When they are not sure about their immunity, test the VZV IgG levels. If positive, they are safe.
○ When they are not immune, they can be treated with IV varicella immunoglobulins as prophylaxis against developing chickenpox. This should be given within ten days of exposure.
When the chickenpox rash starts in pregnancy, they may be treated with oral aciclovir if they present within 24 hours and are more than 20 weeks gestation.
Listeria infection in pregnancy
Listeria
• Listeria is an infectious gram-positive bacteria that causes listeriosis.
• Listeriosis is many times more likely in pregnant women compared with non-pregnant individuals.
• Infection in the mother may be asymptomatic, cause a flu-like illness, or less commonly cause pneumonia or meningoencephalitis.
• Listeriosis in pregnant women has a high rate of miscarriage or fetal death. It can also cause severe neonatal infection.
• Listeria is typically transmitted by unpasteurised dairy products, processed meats and contaminated foods.
• Pregnant women are advised to avoid high-risk foods (e.g. blue cheese) and practice good food hygiene.
Congenital cytomegalovirus in pregnancy
Congenital Cytomegalovirus
® Congenital cytomegalovirus infection occurs due to a cytomegalovirus (CMV) infection in the mother during pregnancy.
® The virus is mostly spread via the infected saliva or urine of asymptomatic children.
® Most cases of CMV in pregnancy do not cause congenital CMV.
The features of congenital CMV are:
® Fetal growth restriction
® Microcephaly
® Hearing loss
® Vision loss
® Learning disability
® Seizures
Congenital toxoplasmosis in pregnancy
Congenital Toxoplasmosis
◊ Infection with the Toxoplasma gondii parasite is usually asymptomatic.
◊ It is primarily spread by contamination with faeces from a cat that is a host of the parasite.
◊ When infection occurs during pregnancy, it can lead to congenital toxoplasmosis.
◊ The risk is higher later in the pregnancy.
There is a classic triad of features in congenital toxoplasmosis:
◊ Intracranial calcification
◊ Hydrocephalus
◊ Chorioretinitis (inflammation of the choroid and retina in the eye)
Parovirus B19 in pregnancy
Infections with parvovirus B19 in pregnancy can lead to several complications, particularly in the first and second trimesters. Complications are:
} Miscarriage or fetal death
} Severe fetal anaemia
} Hydrops fetalis (fetal heart failure)
} Maternal pre-eclampsia-like syndrome
Fetal anaemia is caused by parvovirus infection of the erythroid progenitor cells in the fetal bone marrow and liver.
} These cells produce red blood cells, and the infection causes them to produce faulty red blood cells that have a shorter life span.
} Less red blood cells results in anaemia.
} This anaemia leads to heart failure, referred to as hydrops fetalis.
Maternal pre-eclampsia-like syndrome is also known as mirror syndrome.
} It can be a rare complication of severe fetal heart failure (hydrops fetalis).
} It involves a triad of hydrops fetalis, placental oedema and oedema in the mother.
} It also features hypertension and proteinuria.
Women suspected of parvovirus infection need tests for:
} IgM to parvovirus, which tests for acute infection within the past four weeks
} IgG to parvovirus, which tests for long term immunity to the virus after a previous infection
} Rubella antibodies (as a differential diagnosis)
Treatment is supportive. Women with parvovirus B19 infection need a referral to fetal medicine to monitor for complications and malformations.
Zika virus in pregnancy
Zika Virus
w The zika virus is spread by host Aedes mosquitos in areas of the world where the virus is prevalent.
w It can also be spread by sex with someone infected with the virus.
w It can cause no symptoms, minimal symptoms, or a mild flu-like illness.
In pregnancy, it can lead to congenital Zika syndrome, which involves:
w Microcephaly
w Fetal growth restriction
w Other intracranial abnormalities, such as ventriculomegaly and cerebellar atrophy
Pregnant women that may have contracted the Zika virus should be tested with viral PCR and antibodies to the Zika virus.
w Women with a positive result should be referred to fetal medicine for close monitoring of the pregnancy.
There is no treatment for the virus.
Rhesus incompatibility in pregnancy
Rhesus Incompatibility in Pregnancy
• Women that are rhesus-D positive do not need any additional treatment during pregnancy.
• When a woman that is rhesus-D negative becomes pregnant, we have to consider the possibility that her child will be rhesus positive.
• It is likely at some point in the pregnancy (i.e. childbirth) that the blood from the baby will find a way into the mother’s bloodstream.
• When this happens, the baby’s red blood cells display the rhesus-D antigen.
• The mother’s immune system will recognise this rhesus-D antigen as foreign, and produce antibodies to the rhesus-D antigen.
• The mother has then become sensitised to rhesus-D antigens.
• Usually, this sensitisation process does not cause problems during the first pregnancy.
• During subsequent pregnancies, the mother’s anti-rhesus-D antibodies can cross the placenta into the fetus.
• If that fetus is rhesus-D positive, these antibodies attach themselves to the red blood cells of the fetus and causes the immune system of the fetus to attack them, causing the destruction of the red blood cells (haemolysis).
• The red blood cell destruction caused by antibodies from the mother is called haemolytic disease of the newborn.
Anti D injections
Management
Prevention of sensitisation is the mainstay of management.
• This involves giving intramuscular anti-D injections to rhesus-D negative women.
• There is no way to reverse the sensitisation process once it has occurred, which is why prophylaxis is so essential.
• The anti-D medication works by attaching itself to the rhesus-D antigens on the fetal red blood cells in the mothers circulation, causing them to be destroyed.
• This prevents the mother’s immune system recognising the antigen and creating it’s own antibodies to the antigen.
• It acts as a prevention for the mother becoming sensitised to the rhesus-D antigen.
Anti-D injections are given routinely on two occasions:
• 28 weeks gestation
• Birth (if the baby’s blood group is found to be rhesus-positive)
Anti-D injections should also be given at any time where sensitisation may occur, such as:
• Antepartum haemorrhage
• Amniocentesis procedures
• Abdominal trauma
Anti-D is given within 72 hours of a sensitisation event.
After 20 weeks gestation, the Kleinhauer test is performed to see how much fetal blood has passed into the mother’s blood, to determine whether further doses of anti-D are required.
When should a couple be referred for further testing regarding infertility?
Investigation and referral for infertility should be initiated after the couple has been trying to conceive without success for 12 months. This can be reduced to 6 months if the woman is older than 35, as her ovarian stores are likely to be already reduced and time is more precious.
Some causes of infertility
Causes
• Sperm problems (30%)
• Ovulation problems (25%)
• Tubal problems (15%)
• Uterine problems (10%)
• Unexplained (20%)
40% of infertile couples have a mix of male and female causes.
Female hormone testing for infertility
Female hormone testing involves:
• Serum LH and FSH on day 2 to 5 of the cycle
• Serum progesterone on day 21 of the cycle (or 7 days before the end of the cycle if not a 28-day cycle).
• Anti-Mullerian hormone
• Thyroid function tests when symptoms are suggestive
• Prolactin (hyperprolactinaemia is a cause of anovulation) when symptoms of galactorrhea or amenorrhoea
High FSH suggests poor ovarian reserve (the number of follicles that the woman has left in her ovaries). The pituitary gland is producing extra FSH in an attempt to stimulate follicular development.
High LH may suggest polycystic ovarian syndrome (PCOS).
A rise in progesterone on day 21 indicates that ovulation has occurred, and the corpus luteum has formed and started secreting progesterone.
Anti-Mullerian hormone can be measured at any time during the cycle and is the most accurate marker of ovarian reserve. It is released by the granulosa cells in the follicles and falls as the eggs are depleted. A high level indicates a good ovarian reserve.
Further investigations, often performed in secondary care:
○ Ultrasound pelvis to look for polycystic ovaries or any structural abnormalities in the uterus
○ Hysterosalpingogram to look at the patency of the fallopian tubes
○ Laparoscopy and dye test to look at the patency of the fallopian tubes, adhesions and endometriosis
What is Hysterosalpingogram
Hysterosalpingogram
A hysterosalpingogram is a type of scan used to assess the shape of the uterus and the patency of the fallopian tubes. Not only does it help with diagnosis, but it also has therapeutic benefit. It seems to increase the rate of conception without any other intervention. Tubal cannulation under xray guidance can be performed during the procedure to open up the tubes.
A small tube is inserted into the cervix. A contrast medium is injected through the tube and fills the uterine cavity and fallopian tubes. Xray images are taken, and the contrast shows up on the xray giving an outline of the uterus and tubes. If the dye does not fill one of the tubes, this will be seen on an xray and suggests a tubal obstruction.
There is a risk of infection with the procedure, and often antibiotics are given prophylactically for patients with dilated tubes or a history of pelvic infection. Screening for chlamydia and gonorrhoea should be done before the procedure.
Management when anovulation is the cause of infertility
The options when anovulation is the cause of infertility include:
• Weight loss for overweight patients with PCOS can restore ovulation
• Clomifene may be used to stimulate ovulation
• Letrozole may be used instead of clomifene to stimulate ovulation (aromatase inhibitor with anti-oestrogen effects)
• Gonadotropins may be used to stimulate ovulation in women resistant to clomifene
• Ovarian drilling may be used in polycystic ovarian syndrome
• Metformin may be used when there is insulin insensitivity and obesity (usually associated with PCOS)
Clomifene is an anti-oestrogen (a selective oestrogen receptor modulator). It is given on days 2 to 6 of the menstrual cycle. It stops the negative feedback of oestrogen on the hypothalamus, resulting in a greater release of GnRH and subsequently FSH and LH.
Ovarian drilling involves laparoscopic surgery. The surgeon punctures multiple holes in the ovaries using diathermy or laser therapy. This can improve the woman’s hormonal profile and result in regular ovulation and fertility.
Management of tubal factors affecting fertility
Management of Tubal Factors
The options for women with alterations to the fallopian tubes that prevent the ovum from reaching the sperm and uterus include:
• Tubal cannulation during a hysterosalpingogram
• Laparoscopy to remove adhesions or endometriosis
• In vitro fertilisation (IVF)
Management of uterine factors affecting fertility
Management of Uterine Factors
Surgery may be used to correct polyps, adhesions or structural abnormalities affecting fertility.
Management of sperm problems affecting fertility
Management of Sperm Problems
Surgical sperm retrieval is used when there is a blockage somewhere along the vas deferens preventing sperm from reaching the ejaculated semen. A needle and syringe is used to collect sperm directly from the epididymis through the scrotum.
Surgical correction of an obstruction in the vas deferens may restore male fertility.
Intra-uterine insemination involves collecting and separating out high-quality sperm, then injecting them directly into the uterus to give them the best chance of success. It is unclear whether this is any better than normal intercourse.
Intracytoplasmic sperm injection (ICSI) involves injecting sperm directly into the cytoplasm of an egg. These fertilised eggs become embryos, and are injected into the uterus of the woman. This is useful when there are significant motility issues, a very low sperm count and other issues with the sperm.
Donor insemination with sperm from a donor is another option for male factor infertility.
What factors can affect semen analysis
Factors Affecting Semen Analysis and Sperm Quality and Quantity
Several lifestyle factors may affect the results of semen analysis and the quality and quantity of sperm:
• Hot baths
• Tight underwear
• Smoking
• Alcohol
• Raised BMI
• Caffeine
A repeat sample is indicated after 3 months in borderline results or earlier (2 – 4 weeks) with very abnormal results.
Results of semen analysis
Results
Normal results indicated by the World Health Organisation are:
• Semen volume (more than 1.5ml)
• Semen pH (greater than 7.2)
• Concentration of sperm (more than 15 million per ml)
• Total number of sperm (more than 39 million per sample)
• Motility of sperm (more than 40% of sperm are mobile)
• Vitality of sperm (more than 58% of sperm are active)
• Percentage of normal sperm (more than 4%)
Polyspermia (or polyzoospermia) refers to a high number of sperm in the semen sample (more than 250 million per ml).
Normospermia (or normozoospermia) refers to normal characteristics of the sperm in the semen sample.
Oligospermia (or oligozoospermia) is a reduced number of sperm in the semen sample. It is classified as:
○ Mild oligospermia (10 to 15 million / ml)
○ Moderate oligospermia (5 to 10 million / ml)
○ Severe oligospermia (less than 5 million / ml)
Cryptozoospermia refers to very few sperm in the semen sample (less than 1 million / ml).
Azoospermia is the absence of sperm in the semen.
Pre testicular causes of low sperm
Pre-Testicular Causes
Testosterone is necessary for sperm creation. The hypothalamo-pituitary-gonadal axis controls testosterone. Hypogonadotrophic hypogonadism (low LH and FSH resulting in low testosterone), can be due to:
• Pathology of the pituitary gland or hypothalamus
• Suppression due to stress, chronic conditions or hyperprolactinaemia
• Kallman syndrome
Testicular causes of low sperm count
Testicular Causes
Testicular damage from:
• Mumps
• Undescended testes
• Trauma
• Radiotherapy
• Chemotherapy
• Cancer
Genetic or congenital disorders that result in defective or absent sperm production, such as: ○ Klinefelter syndrome ○ Y chromosome deletions ○ Sertoli cell-only syndrome ○ Anorchia (absent testes)
Post testicular causes of low sperm count
Post-Testicular Causes
Obstruction preventing sperm being ejaculated can be caused by:
§ Damage to the testicle or vas deferens from trauma, surgery or cancer
§ Ejaculatory duct obstruction
§ Retrograde ejaculation
§ Scarring from epididymitis, for example, caused by chlamydia
§ Absence of the vas deferens (may be associated with cystic fibrosis)
§ Young’s syndrome (obstructive azoospermia, bronchiectasis and rhinosinusitis)
Investigations following abnormal semen analysis
Investigations
The initial steps for investigating abnormal semen analysis include a history, examination, repeat sample and ultrasound of the testes.
Patients with abnormal semen results are referred to a urologist for further investigations. Further investigations that may be considered include:
• Hormonal analysis with LH, FSH and testosterone levels
• Genetic testing
• Further imaging, such as transrectal ultrasound or MRI
• Vasography, which involves injecting contrast into the vas deferens and performing xray to assess for obstruction
• Testicular biopsy
Management of male factor infertility
Management
Management depends on the underlying cause, and can involve:
• Surgical sperm retrieval where there is obstruction
• Surgical correction of an obstruction in the vas deferens
• Intra-uterine insemination involves separating high-quality sperm, then injecting them into the uterus
• Intracytoplasmic sperm injection (ICSI) involves injecting sperm directly into the cytoplasm of an egg
• Donor insemination involves sperm from a donor
Process of IVF
Process
There are a number of steps involved in the process of IVF:
• Suppressing the natural menstrual cycle
• Ovarian stimulation
• Oocyte collection
• Insemination / intracytoplasmic sperm injection (ICSI)
• Embryo culture
• Embryo transfer
Complications of IVF
Complications
The main complications relating to the overall process are:
• Failure
• Multiple pregnancy
• Ectopic pregnancy
• Ovarian hyperstimulation syndrome
There is a small risk of complications relating to the egg collection procedure:
• Pain
• Bleeding
• Pelvic infection
• Damage to the bladder or bowel
What is ovarian hyperstimulation syndrome
Ovarian hyperstimulation syndrome (OHSS) is a complication of ovarian stimulation during IVF infertility treatment. It is associated with the use of human chorionic gonadotropin (hCG) to mature the follicles during the final steps of ovarian stimulation.
Pathophysiology of ovarian hyper stimulation syndrome
Pathophysiology
The primary mechanism for OHSS is an increase in vascular endothelial growth factor (VEGF) released by the granulosa cells of the follicles. VEGF increases vascular permeability, causing fluid to leak from capillaries. Fluid moves from the intravascular space to the extravascular space. This results in oedema, ascites and hypovolaemia.
The use of gonadotrophins (LH and FSH) during ovarian stimulation results in the development of multiple follicles. OHSS is provoked by the “trigger injection” of hCG 36 hours before oocyte collection. HCG stimulates the release of VEGF from the follicles. The features of the condition begin to develop after the hCG injection.
There is also activation of the renin-angiotensin system. A notable finding in patients with OHSS is a raised renin level. The renin level correlates with the severity of the condition.
How is development of ovarian hyperstimulation syndrome tried to be prevented?
Prevention
Women are individually assessed for their risk of developing OHSS.
During stimulation with gonadotrophins, they are monitored with:
• Serum oestrogen levels (higher levels indicate a higher risk)
• Ultrasound monitor of the follicles (higher number and larger size indicate a higher risk)
In women at higher risk several strategies may be used to reduce the risk: ○ Use of the GnRH antagonist protocol (rather than the GnRH agonist protocol) ○ Lower doses of gonadotrophins ○ Lower dose of the hCG injection ○ Alternatives to the hCG injection (i.e. a GnRH agonist or LH)
Risk factors for getting ovarian hyperstimulation syndrome
Risk Factors
• Younger age
• Lower BMI
• Raised anti-Müllerian hormone
• Higher antral follicle count
• Polycystic ovarian syndrome
• Raised oestrogen levels during ovarian stimulation
Features and symptoms of ovarian hyperstimulation syndrome
Features
Early OHSS presents within 7 days of the hCG injection. Late OHSS presents from 10 days onwards.
Features of the condition include:
• Abdominal pain and bloating
• Nausea and vomiting
• Diarrhoea
• Hypotension
• Hypovolaemia
• Ascites
• Pleural effusions
• Renal failure
• Peritonitis from rupturing follicles releasing blood
• Prothrombotic state (risk of DVT and PE)
Severity of ovarian hyperstimulation syndrome
Severity
The severity is determined based on the clinical features:
• Mild: Abdominal pain and bloating
• Moderate: Nausea and vomiting with ascites seen on ultrasound
• Severe: Ascites, low urine output (oliguria), low serum albumin, high potassium and raised haematocrit (>45%)
• Critical: Tense ascites, no urine output (anuria), thromboembolism and acute respiratory distress syndrome (ARDS)
Management of ovarian hyper stimulation syndrome
Management
Management is supportive with treatment of any complications. This involves:
• Oral fluids
• Monitoring of urine output
• Low molecular weight heparin (to prevent thromboembolism)
• Ascitic fluid removal (paracentesis) if required
• IV colloids (e.g. human albumin solution)
Patients with mild to moderate OHSS are often managed as an outpatient. Severe cases require admission, and critical cases may require admission to the intensive care unit (ICU).
TOM TIP: Haematocrit may be monitored to assess the volume of fluid in the intravascular space. Haematocrit is the concentration of red blood cells in the blood. When the haematocrit goes up, this indicates less fluid in the intravascular space, as the blood is becoming more concentrated. Raised haematocrit can indicate dehydration.
What is an ectopic pregnancy?
Ectopic pregnancy is when a pregnancy is implanted outside the uterus. The most common site is a fallopian tube. An ectopic pregnancy can also implant in the entrance to the fallopian tube (cornual region), ovary, cervix or abdomen.
Risk factors of having an ectopic pregnancy
Risk Factors
Certain factors can increase the risk of ectopic pregnancy:
• Previous ectopic pregnancy
• Previous pelvic inflammatory disease
• Previous surgery to the fallopian tubes
• Intrauterine devices (coils)
• Older age
• Smoking
Presentation of an ectopic pregnancy
Presentation
Ectopic pregnancy typically presents around 6 – 8 weeks gestation.
Have a low threshold for suspecting an ectopic pregnancy, even in atypical presentations. Always ask about the possibility of pregnancy, missed periods and recent unprotected sex in women presenting with lower abdominal pain.
The classic features of an ectopic pregnancy include:
• Missed period
• Constant lower abdominal pain in the right or left iliac fossa
• Vaginal bleeding
• Lower abdominal or pelvic tenderness
• Cervical motion tenderness (pain when moving the cervix during a bimanual examination)
It is also worth asking about: ○ Dizziness or syncope (blood loss) ○ Shoulder tip pain (peritonitis)
Ultrasound findings of an ectopic pregnancy
Ultrasound Findings
A transvaginal ultrasound scan is the investigation of choice for diagnosing a miscarriage. A gestational sac containing a yolk sac or fetal pole may be seen in a fallopian tube.
Sometimes a non-specific mass may be seen in the tube. When a mass containing an empty gestational sac is seen, this may be referred to as the “blob sign”, “bagel sign” or “tubal ring sign” (all referring to the same appearance).
A mass representing a tubal ectopic pregnancy moves separately to the ovary. The mass may look similar to a corpus luteum; however, a corpus luteum will move with the ovary.
Features that may also indicate an ectopic pregnancy are:
• An empty uterus
• Fluid in the uterus, which may be mistaken as a gestational sac (“pseudogestational sac”)
Criteria for expectant management in an ectopic pregnancy
Criteria for expectant management:
○ Follow up needs to be possible to ensure successful termination
○ The ectopic needs to be unruptured
○ Adnexal mass < 35mm
○ No visible heartbeat
○ No significant pain
○ HCG level < 1500 IU / l
Women with expectant management need careful follow up with close monitoring of hCG levels, and quick and easy access to services if their condition changes.
Types of management for an ectopic pregnancy
There are three options for terminating an ectopic pregnancy:
• Expectant management (awaiting natural termination)
• Medical management (methotrexate)
• Surgical management (salpingectomy or salpingotomy)
Medical management of an ectopic pregnancy
Management with Methotrexate
Methotrexate is highly teratogenic (harmful to pregnancy). It is given as an intramuscular injection into a buttock. This halts the progress of the pregnancy and results in spontaneous termination.
Women treated with methotrexate are advised not to get pregnant for 3 months following treatment. This is because the harmful effects of methotrexate on pregnancy can last this long.
Common side effects of methotrexate include:
• Vaginal bleeding
• Nausea and vomiting
• Abdominal pain
• Stomatitis (inflammation of the mouth)
Criteria for methotrexate are the same as expectant management, except:
§ HCG level must be < 5000 IU / l
§ Confirmed absence of intrauterine pregnancy on ultrasound
When is surgery used for an ectopic pregnancy
Surgical Management
Anyone that does not meet the criteria for expectant or medical management requires surgical management. Most patients with an ectopic pregnancy will require surgical management. This include those with:
• Pain
• Adnexal mass > 35mm
• Visible heartbeat
• HCG levels > 5000 IU / l
Two surgical options for an ectopic pregnancy
There are two options for surgical management of ectopic pregnancy:
○ Laparoscopic salpingectomy
○ Laparoscopic salpingotomy
Laparoscopic salpingectomy is the first-line treatment for ectopic pregnancy. This involves a general anaesthetic and key-hole surgery with removal of the affected fallopian tube, along with the ectopic pregnancy inside the tube.
Laparoscopic salpingotomy may be used in women at increased risk of infertility due to damage to the other tube. The aim is to avoid removing the affected fallopian tube. A cut is made in the fallopian tube, the ectopic pregnancy is removed, and the tube is closed.
There is an increased risk of failure to remove the ectopic pregnancy with salpingotomy compared with salpingectomy. NICE state up to 1 in 5 women having salpingotomy may need further treatment with methotrexate or salpingectomy.
Anti-rhesus D prophylaxis is given to rhesus negative women having surgical management of ectopic pregnancy.
Early vs late miscarriage
Miscarriage is the spontaneous termination of a pregnancy. Early miscarriage is before 12 weeks gestation. Late miscarriage is between 12 and 24 weeks gestation.
Missed miscarriage
• Missed miscarriage – the fetus is no longer alive, but no symptoms have occurred
Threatened miscarriage
• Threatened miscarriage – vaginal bleeding with a closed cervix and a fetus that is alive
Inevitable miscarriage
• Inevitable miscarriage – vaginal bleeding with an open cervix
Incomplete miscarriage
• Incomplete miscarriage – retained products of conception remain in the uterus after the miscarriage
Complete miscarriage
• Complete miscarriage – a full miscarriage has occurred, and there are no products of conception left in the uterus
Anembryonic pregnancy
• Anembryonic pregnancy – a gestational sac is present but contains no embryo
Diagnosing a miscarriage
TV scan is gold standard method.
There are three key features that the sonographer looks for in an early pregnancy. These appear sequentially as the pregnancy develops. As each appears, the previous feature becomes less relevant in assessing the viability of the pregnancy. These features are:
• Mean gestational sac diameter
• Fetal pole and crown-rump length
• Fetal heartbeat
When a fetal heartbeat is visible, the pregnancy is considered viable. A fetal heartbeat is expected once the crown-rump length is 7mm or more.
Management of miscarriage less than 6 weeks gestation
Management
Less Than 6 Weeks Gestation
Women with a pregnancy less than 6 weeks’ gestation presenting with bleeding can be managed expectantly provided they have no pain and no other complications or risk factors (e.g. previous ectopic).
Expectant management before 6 weeks gestation involves awaiting the miscarriage without investigations or treatment. An ultrasound is unlikely to be helpful this early as the pregnancy will be too small to be seen.
A repeat urine pregnancy test is performed after 7 – 10 days, and if negative, a miscarriage can be confirmed. When bleeding continues, or pain occurs, referral and further investigation is indicated.
Management of a miscarriage more than 6 weeks gestation
More Than 6 Weeks Gestation
The NICE guidelines (2019) suggest referral to an early pregnancy assessment service (EPAU) for women with a positive pregnancy test (more than 6 weeks’ gestation) and bleeding.
The early pregnancy assessment unit will arrange an ultrasound scan. Ultrasound will confirm the location and viability of the pregnancy. It is essential always to consider and exclude an ectopic pregnancy.
There are three options for managing a miscarriage:
• Expectant management (do nothing and await a spontaneous miscarriage)
• Medical management (misoprostol)
• Surgical management
Expectant management of a miscarriage
Expectant Management
Expectant management is offered first-line for women without risk factors for heavy bleeding or infection. 1 – 2 weeks are given to allow the miscarriage to occur spontaneously. A repeat urine pregnancy test should be performed three weeks after bleeding and pain settle to confirm the miscarriage is complete.
Persistent or worsening bleeding requires further assessment and repeat ultrasound, as this may indicate an incomplete miscarriage and require additional management.
Medical management of a miscarriage
Medical Management
Misoprostol is a prostaglandin analogue, meaning it binds to prostaglandin receptors and activates them. Prostaglandins soften the cervix and stimulate uterine contractions.
Medical management of miscarriage involves using a dose of misoprostol to expedite the process of miscarriage. This can be as a vaginal suppository or an oral dose.
The key side effects of misoprostol are:
• Heavier bleeding
• Pain
• Vomiting
• Diarrhoea
Surgical management of a miscarriage
Surgical Management
Surgical management can be performed under local or general anaesthetic.
There are two options for surgical management of a miscarriage:
• Manual vacuum aspiration under local anaesthetic as an outpatient
• Electric vacuum aspiration under general anaesthetic
Prostaglandins (misoprostol) are given before surgical management to soften the cervix.
Anti-rhesus D prophylaxis is given to rhesus negative women having surgical management of miscarriage.
Manual vacuum aspiration involves a local anaesthetic applied to the cervix. A tube attached to a specially designed syringe is inserted through the cervix into the uterus. The person performing the procedure then manually uses the syringe to aspirate contents of the uterus. To consider manual vacuum aspiration, women must find the process acceptable and be below 10 weeks gestation. It is more appropriate for women that have previously given birth (parous women).
Electric vacuum aspiration is the traditional surgical management of miscarriage. It involves a general anaesthetic. The operation is performed through the vagina and cervix without any incisions. The cervix is gradually widened using dilators, and the products of conception are removed through the cervix using an electric-powered vacuum.
What is a recurrent miscarriage
Three or more consecutive miscarriage
Causes of recurrent miscarriages
Causes
• Idiopathic (particularly in older women)
• Antiphospholipid syndrome
• Hereditary thrombophilias
• Uterine abnormalities
• Genetic factors in parents (e.g. balanced translocations in parental chromosomes)
• Chronic histiocytic intervillositis
• Other chronic diseases such as diabetes, untreated thyroid disease and systemic lupus erythematosus (SLE)
Anti phospholipid syndrome
Antiphospholipid Syndrome
Antiphospholipid syndrome is a disorder associated with antiphospholipid antibodies, where blood becomes prone to clotting. The patient is in a hyper-coagulable state. The main associations are with thrombosis and complications in pregnancy, particularly recurrent miscarriage.
Antiphospholipid syndrome can occur on its own, or secondary to an autoimmune condition such as systemic lupus erythematosus.
The risk of miscarriage in patients with antiphospholipid syndrome is reduced by using both:
• Low dose aspirin
• Low molecular weight heparin (LMWH)
TOM TIP: If you remember one cause of recurrent miscarriages, remember antiphospholipid syndrome. Consider this in patients presenting in exams with recurrent miscarriages. There may be a past history of deep vein thrombosis. Test for antiphospholipid antibodies, and treatment is with aspirin and LMWH.
Hereditary thrombophillias likely to cause recurrent miscarriage
Hereditary Thrombophilias
The key inherited thrombophilias to remember are:
• Factor V Leiden (most common)
• Factor II (prothrombin) gene mutation
• Protein S deficiency
Uterine abnormalities which can cause recurrent miscarriage
Uterine Abnormalities
Several uterine abnormalities can cause recurrent miscarriages:
• Uterine septum (a partition through the uterus)
• Unicornuate uterus (single-horned uterus)
• Bicornuate uterus (heart-shaped uterus)
• Didelphic uterus (double uterus)
• Cervical insufficiency
• Fibroids
Chronic Histiocytic Intervillositis
Chronic Histiocytic Intervillositis
Chronic histiocytic intervillositis is a rare cause of recurrent miscarriage, particularly in the second trimester. It can also lead to intrauterine growth restriction (IUGR) and intrauterine death.
The condition is poorly understood. Histiocytes and macrophages build up in the placenta, causing inflammation and adverse outcomes. It is diagnosed by placental histology showing infiltrates of mononuclear cells in the intervillous spaces.
Investigations following recurrent miscarriage
Investigations
Patients should be referred to a specialist in recurrent miscarriage for further investigation. Investigations include:
• Antiphospholipid antibodies
• Testing for hereditary thrombophilias
• Pelvic ultrasound
• Genetic testing of the products of conception from the third or future miscarriages
• Genetic testing on parents
Management of recurrent miscarriage
Management
Management of recurrent miscarriage depends on the underlying cause.
There is new evidence from the PRISM trial that suggests a benefit to using vaginal progesterone pessaries during early pregnancy for women with recurrent miscarriages presenting with bleeding. This may become part of guidelines in the future. At present, the RCOG guidelines on recurrent miscarriage (2011) state there is insufficient evidence for progesterone supplementation.
Medical abortion method
Medical Abortion
A medical abortion is most appropriate earlier in pregnancy, but can be used at any gestation. It involves two treatments:
• Mifepristone (anti-progestogen)
• Misoprostol (prostaglandin analogue) 1 – 2 day later
Mifepristone is an anti-progestogen medication that blocks the action of progesterone, halting the pregnancy and relaxing the cervix.
Misoprostol is a prostaglandin analogue, meaning it binds to prostaglandin receptors and activates them. Prostaglandins soften the cervix and stimulate uterine contractions. From 10 weeks gestation, additional misoprostol doses (e.g. every 3 hours) are required until expulsion.
Rhesus negative women with a gestational age of 10 weeks or above having a medical TOP should have anti-D prophylaxis.
Surgical abortion method
Surgical Abortion
Surgical abortion can be performed, depending on preference and gestational age, under:
• Local anaesthetic
• Local anaesthetic plus sedation
• General anaesthetic
Prior to surgical abortion, medications are used for cervical priming. This involves softening and dilating the cervix with misoprostol, mifepristone or osmotic dilators. Osmotic dilators are devices inserted into the cervix, that gradually expand as they absorb fluid, opening the cervical canal.
There are two options for surgical abortion:
○ Cervical dilatation and suction of the contents of the uterus (usually up to 14 weeks)
○ Cervical dilatation and evacuation using forceps (between 14 and 24 weeks)
Rhesus negative women having a surgical TOP should have anti-D prophylaxis. The NICE guidelines (2019) say it should be considered in women less than 10 weeks gestation.
Post abortion after care
Post-Abortion Care
Women may experience vaginal bleeding and abdominal cramps intermittently for up to 2 weeks after the procedure. A urine pregnancy test is performed 3 weeks after the abortion to confirm it is complete. Contraception is discussed and started where appropriate. Support and counselling is offered.
Complications of an abortion
Complications
• Bleeding
• Pain
• Infection
• Failure of the abortion (pregnancy continues)
• Damage to the cervix, uterus or other structures
Hyperemesis Gravidarum
Hyperemesis Gravidarum
Hyperemesis gravidarum is the severe form of nausea and vomiting in pregnancy. The RCOG guideline (2016) criteria for diagnosing hyperemesis gravidarum are “protracted” NVP plus:
• More than 5 % weight loss compared with before pregnancy
• Dehydration
• Electrolyte imbalance
Management of Hyperemesis Gravidarum
Antiemetics are used to suppress nausea. Vaguely in order of preference and known safety, the choices are:
1. Prochlorperazine (stemetil)
2. Cyclizine
3. Ondansetron
4. Metoclopramide
Ranitidine or omeprazole can be used if acid reflux is a problem.
The RCOG also suggest complementary therapies that may be considered by the woman:
○ Ginger
○ Acupressure on the wrist at the PC6 point (inner wrist) may improve symptoms
When would cases of Hyperemesis Gravidarum be admitted to hospital
Mild cases can be managed with oral antiemetics at home. Admission should be considered when:
§ Unable to tolerate oral antiemetics or keep down any fluids
§ More than 5 % weight loss compared with pre-pregnancy
§ Ketones are present in the urine on a urine dipstick (2 + ketones on the urine dipstick is significant)
§ Other medical conditions need treating that required admission
Moderate-severe cases may require ambulatory care (e.g. early pregnancy assessment unit) or admission for:
□ IV or IM antiemetics
□ IV fluids (normal saline with added potassium chloride)
□ Daily monitoring of U&Es while having IV therapy
□ Thiamine supplementation to prevent deficiency (prevents Wernicke-Korsakoff syndrome)
□ Thromboprophylaxis (TED stocking and low molecular weight heparin) during admission
What is a molar pregnancy and what are the two types?
A hydatidiform mole is a type of tumour that grows like a pregnancy inside the uterus. This is called a molar pregnancy.
There are two types of molar pregnancy: a complete mole and a partial mole.
A complete mole occurs when two sperm cells fertilise an ovum that contains no genetic material (an “empty ovum”). These sperm then combine genetic material, and the cells start to divide and grow into a tumour called a complete mole. No fetal material will form.
A partial mole occurs when two sperm cells fertilise a normal ovum (containing genetic material) at the same time. The new cell now has three sets of chromosomes (it is a haploid cell). The cell divides and multiplies into a tumour called a partial mole. In a partial mole, some fetal material may form.
Diagnosis of a molar pregnancy
Diagnosis
Molar pregnancy behaves like a normal pregnancy. Periods will stop and the hormonal changes of pregnancy will occur. There are a few things that can indicate a molar pregnancy versus a normal pregnancy:
• More severe morning sickness
• Vaginal bleeding
• Increased enlargement of the uterus
• Abnormally high hCG
• Thyrotoxicosis (hCG can mimic TSH and stimulate the thyroid to produce excess T3 and T4)
Ultrasound of the pelvis shows a characteristic “snowstorm appearance” of the pregnancy. Provisional diagnosis can be made by ultrasound and confirmed with histology of the mole after evacuation.
Management of a molar pregnancy
Management
Management involves evacuation of the uterus to remove the mole. The products of conception need to be sent for histological examination to confirm a molar pregnancy. Patients should be referred to the gestational trophoblastic disease centre for management and follow up. The hCG levels are monitored until they return to normal. Occasionally the mole can metastasise, and the patient may require systemic chemotherapy.
3 stages of labour
Labour and delivery normally occur between 37 and 42 weeks gestation.
There are three stages of labour:
• First stage – from the onset of labour (true contractions) until 10cm cervical dilatation
• Second stage – from 10cm cervical dilatation until delivery of the baby
• Third stage – from delivery of the baby until delivery of the placenta
First stage of labour
First Stage
The first stage of labour is from the onset of labour (true contractions) until the cervix is fully dilated to 10cm. It involves cervical dilation (opening up) and effacement (getting thinner). The “show” refers to the mucus plug in the cervix, which prevents bacteria from entering the uterus during pregnancy, falling out and creating space for the baby to pass through.
The first stage has three phases:
• Latent phase – from 0 to 3cm dilation of the cervix. This progresses at around 0.5cm per hour. There are irregular contractions.
• Active phase – from 3cm to 7cm dilation of the cervix. This progresses at around 1cm per hour, and there are regular contractions.
• Transition phase – from 7cm to 10cm dilation of the cervix. This progresses at around 1cm per hour, and there are strong and regular contractions.
Braxton-Hicks Contractions
Braxton-Hicks Contractions
Braxton-Hicks contractions are occasional irregular contractions of the uterus. They are usually felt during the second and third trimester. Women can experience temporary and irregular tightening or mild cramping in the abdomen. These are not true contractions, and they do not indicate the onset of labour. They do not progress or become regular. Staying hydrated and relaxing can help reduce Braxton-Hicks contractions.
What are the signs of labour?
The signs of labour are:
• Show (mucus plug from the cervix)
• Rupture of membranes
• Regular, painful contractions
• Dilating cervix on examination
Latent and established signs of the first part of labour
NICE guidelines on intrapartum care (2017) refer to the latent first stage and established list stage.
The latent first stage is when there are both:
○ Painful contractions
○ Changes to the cervix, with effacement and dilation up to 4cm
The established first stage of labour is when there are both: § Regular, painful contractions § Dilatation of the cervix from 4cm onwards
Second stage - passive stage of labour
Time between being fully dilated and urge to push
Complete cervical dilatation but no pushing
Often seen in women with epidural anaesthesia
Recommended to leave 1-2 hours before pushing to reduce rate of instrumental
delivery
Second stage - active stage of labour
Maternal pushing until baby is born
Should take less than 2 hours for primips, 1 hour for multips
Assess fetal heart rate every 5 mins, may need syntocin if contractions wane, hourly vaginal examination and
record urination
As head descends, perineum stretches – applied gentle pressure on the perineum controls delivery of the head,
reducing perineal tearing and reducing cranial injury to fetus
Third stage of labour
Third stage
Delivery of the placenta
Placenta separates from uterus and uterus contracts to 24 week size
Marked by a rush of blood with lengthening of the cord
Normally takes under 1 hour but accelerated to around 5 mins by use of syntometrine (syntocin plus ergometrine IM) given as anterior shoulder is born
Decreases incidence of PPH but can precipitate MI in susceptible individuals – just give oxytocin instead
Check placenta for completeness
Premature labour
Prematurity
Prematurity is defined as birth before 37 weeks gestation. The more premature the baby, the worse the outcomes.
Babies are considered non-viable below 23 weeks gestation. Generally, from 23 to 24 weeks, resuscitation is not considered in babies that do not show signs of life. Babies born at 23 weeks have around a 10% chance of survival. From 24 weeks onwards, there is an increased chance of survival, and full resuscitation is offered.
The World Health Organisation classify prematurity as:
• Under 28 weeks: extreme preterm
• 28 – 32 weeks: very preterm
• 32 – 37 weeks: moderate to late preterm
Vaginal progesterone use for prophylaxis
Vaginal Progesterone
Progesterone can be given vaginally via gel or pessary as prophylaxis for preterm labour. Progesterone has a role in maintaining pregnancy and preventing labour by decreasing activity of the myometrium and preventing the cervix remodelling in preparation for delivery. This is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation.
Prophylaxis of preterm labour using cervical cerclage
Cervical Cerclage
Cervical cerclage involves putting a stitch in the cervix to add support and keep it closed. This involves a spinal or general anaesthetic. The stitch is removed when the woman goes into labour or reaches term.
Cervical cerclage is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had a previous premature birth or cervical trauma (e.g. colposcopy and cone biopsy).
“Rescue” cervical cerclage may also be offered between 16 and 27 + 6 weeks when there is cervical dilatation without rupture of membranes, to prevent progression and premature delivery.
Preterm prelabour rupture of membranes
Preterm Prelabour Rupture of Membranes
Preterm prelabour rupture of membranes is where the amniotic sac ruptures, releasing amniotic fluid, before the onset of labour and in a preterm pregnancy (under 37 weeks gestation).
How is preterm prelabour rupture of membranes diagnosed?
Diagnosis
Rupture of membranes can be diagnosed by speculum examination revealing pooling of amniotic fluid in the vagina. No tests are required.
Where there is doubt about the diagnosis, tests can be performed:
• Insulin-like growth factor-binding protein-1 (IGFBP-1) is a protein present in high concentrations in amniotic fluid, which can be tested on vaginal fluid if there is doubt about rupture of membranes
• Placental alpha-microglobin-1 (PAMG-1) is a similar alternative to IGFBP-1
Preterm prelabour rupture of the membranes management
Management
Prophylactic antibiotics should be given to prevent the development of chorioamnionitis. The NICE guidelines (2019) recommend erythromycin 250mg four times daily for ten days, or until labour is established if within ten days.
Induction of labour may be offered from 34 weeks to initiate the onset of labour.
Preterm labour with intact membranes
Preterm labour with intact membranes involves regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
How is preterm labour managed?
Management
There are several options for improving the outcomes in preterm labour:
○ Fetal monitoring (CTG or intermittent auscultation)
○ Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour
○ Maternal corticosteroids: can be offered before 35 weeks gestation to reduce neonatal morbidity and mortality
○ IV magnesium sulphate: can be given before 34 weeks gestation and helps protect the baby’s brain
○ Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby at birth
Tocolysis (medication used to stop uterine contractions)
Tocolysis
Tocolysis involves using medications to stop uterine contractions. Nifedipine, a calcium channel blocker, is the medication of choice for tocolysis. Atosiban is an oxytocin receptor antagonist that can be used as an alternative when nifedipine is contraindicated.
Tocolysis can be used between 24 and 33 + 6 weeks gestation in preterm labour to delay delivery and buy time for further fetal development, administration of maternal steroids or transfer to a more specialist unit (e.g. with a neonatal ICU). It is only used as a short term measure (i.e. less than 48 hours).
Use of antenatal steroids in pre term labour
Antenatal Steroids
Giving the mother corticosteroids helps to develop the fetal lungs and reduce respiratory distress syndrome after delivery. They are used in women with suspected preterm labour of babies less than 36 weeks gestation.
An example regime would be two doses of intramuscular betamethasone, 24 hours apart.
Use of magnesium sulfate in preterm labour
Magnesium Sulfate
Giving the mother IV magnesium sulfate helps protect the fetal brain during premature delivery. It reduces the risk and severity of cerebral palsy. Magnesium sulphate is given within 24 hours of delivery of preterm babies of less than 34 weeks gestation. It is given as a bolus, followed by an infusion for up to 24 hours or until birth.
Mothers need close monitoring for magnesium toxicity at least four hourly. This involves close monitoring of observations, as well as tendon reflexes (usually patella reflex). Key signs of toxicity are:
• Reduced respiratory rate
Reduced blood pressure
• Absent reflexes
Indications for induction of labour
Indications
Induction of labour can be used where patients go over the due date. IOL is offered between 41 and 42 weeks gestation.
Induction of labour is also offered in situations where it is beneficial to start labour early, such as:
• Prelabour rupture of membranes
• Fetal growth restriction
• Pre-eclampsia
• Obstetric cholestasis
• Existing diabetes
• Intrauterine fetal death
• Breech
• Macrosomia
• Insufficient uterine contractions
• Prolonged labour
Contraindications to Induction
• Abnormal fetal lie
• Placenta praevia
• Cord prolapse
• Active genital herpes
What scoring system is used to measure whether labour should be induced?
The Bishop score is a scoring system used to determine whether to induce labour.
Five things are assessed and given a score based on different criteria (minimum score is 0 and maximum is 13):
• Fetal station (scored 0 – 3)
• Cervical position (scored 0 – 2)
• Cervical dilatation (scored 0 – 3)
• Cervical effacement (scored 0 – 3)
• Cervical consistency (scored 0 – 2)
A score of 8 or more predicts a successful induction of labour. A score below this suggests cervical ripening may be required to prepare the cervix.
How is induction of labour monitored?
Monitoring
There are two means for monitoring during the induction of labour.
• Cardiotocography (CTG) to assess the fetal heart rate and uterine contractions before and during induction of labour
• Bishop score before and during induction of labour to monitor the progress
Further management if induction of labour doesn’t work within 24 hours
Ongoing Management
Most women will give birth within 24 hours of the start of induction of labour.
The options when there is slow or no progress are:
• Further vaginal prostaglandins
• Artificial rupture of membranes and oxytocin infusion
• Cervical ripening balloon (CRB)
• Elective caesarean section
What is uterine hyperstimulation?
Uterine Hyperstimulation
• Uterine hyperstimulation is the main complication of induction of labour with vaginal prostaglandins.
• This is where the contraction of the uterus is prolonged and frequent, causing fetal distress and compromise.
The criteria for uterine hyperstimulation varies slightly between guidelines (always check local policies and involve experienced seniors). The two criteria often given are:
• Individual uterine contractions lasting more than 2 minutes in duration
• More than five uterine contractions every 10 minutes
Complications of uterine hyper stimulation and how is it managed?
Uterine hyperstimulation can lead to:
• Fetal compromise, with hypoxia and acidosis
• Emergency caesarean section
• Uterine rupture
Management of uterine hyperstimulation involves:
• Removing the vaginal prostaglandins, or stopping the oxytocin infusion
• Tocolysis with terbutaline
Complications of induction
Complications of Induction
• Uterine hyper stimulation
• Uterine rupture
• Intrauterine infection
• Prolapsed cord
• Amniotic fluid embolism
May lead to necessity of caesarean section
Different options for induction of labour
Membrane sweep
Vaginal prostaglandin E2 (dinoprostone)
Artificial rupture of membranes with an oxytocin infusion
Oral mifepristone (anti-progesterone) plus misoprostol are used to induce labour where intrauterine fetal death has occurred.
What is a membrane sweep (induction of labour)
Membrane sweep involves inserting a finger into the cervix to stimulate the cervix and begin the process of labour.
• It can be performed in antenatal clinic, and if successful, should produce the onset of labour within 48 hours.
• A membrane sweep is not considered a full method of inducing labour, and is more of an assistance before full induction of labour.
• It is used from 40 weeks gestation to attempt to initiate labour in women over their EDD.
Vaginal prostaglandin use in induction of labour
Vaginal prostaglandin E2 (dinoprostone) involves inserting a gel, tablet (Prostin) or pessary (Propess) into the vagina.
• The pessary is similar to a tampon, and slowly releases local prostaglandins over 24 hours.
• This stimulates the cervix and uterus to cause the onset of labour.
• This is usually done in the hospital setting so that the woman can be monitored before being allowed home to await the full onset of labour.
Cervical ripening balloon use in induction of labour
Cervical ripening balloon (CRB) is a silicone balloon that is inserted into the cervix and gently inflated to dilate the cervix.
• This is used as an alternative where vaginal prostaglandins are not preferred, usually in women with a previous caesarean section, where vaginal prostaglandins have failed or multiparous women (para ≥ 3).
Artificial rupture of membranes with an oxytocin infusion
Artificial rupture of membranes with an oxytocin infusion can also be used to induce labour, although this would only be used where there are reasons not to use vaginal prostaglandins.
• It can be used to progress the induction of labour after vaginal prostaglandins have been used.
Contraindications to oxytocin
• Possible obstructed labour
• Feto-pelvic disproportion
• Severe cardiovascular disease
What is used to induce labour after intrauterine death has occurred?
Oral mifepristone (anti-progesterone) plus misoprostol are used to induce labour where intrauterine fetal death has occurred.
What is cardiotocography?
Cardiotocography (CTG) is used to measure the fetal heart rate and the contractions of the uterus.
It is also known as electronic fetal monitoring.
It is a useful way of monitoring the condition of the fetus and the activity of labour.
CTG can help guide decision making and delivery. However, it should not be used in isolation for decision making, and it is essential to take into account the overall clinical picture.
Indications for continuous CTG monitoring in labour
Indications for Continuous CTG Monitoring
The indications for continuous CTG monitoring in labour include:
○ Sepsis
○ Maternal tachycardia (> 120)
○ Significant meconium
○ Pre-eclampsia (particularly blood pressure > 160 / 110)
○ Fresh antepartum haemorrhage
○ Delay in labour
○ Use of oxytocin
○ Disproportionate maternal pain
What can CTG measure during in labour?
Key Features
There are five key features to look for on a CTG:
§ Contractions – the number of uterine contractions per 10 minutes
§ Baseline rate – the baseline fetal heart rate
§ Variability – how the fetal heart rate varies up and down around the baseline
§ Accelerations – periods where the fetal heart rate spikes
§ Decelerations – periods where the fetal heart rate drops
