Obstetrics Flashcards
How many chromosomes does the primary oocyte have?
46
How many chromosomes does the mature ovum have?
23
Which hormone suppresses the mother’s immune reaction to foetal antigens?
Progesterone
When does the corpus luteum stop producing progesterone?
10 weeks gestation, then placenta produces it.
G4 P3
A pregnant woman with 3 previous deliveries.
G1 P0+1
A non-pregnant woman with a previous miscarriage.
A non-pregnant woman with a previous birth of healthy twins
G1 P1
A non-pregnant woman with a previous stillbirth
G1 P1
What age do foetal movements start?
18-20 weeks
What is the main complication of induction of labour?
Uterine hyperstimulation
What is the normal frequency of contractions?
4 or less in 10 mins
Is there a safe level of alcohol in pregnancy?
No!
Describe the features of foetal alcohol syndrome
- Microcephaly (small head)
- Thin upper lip
- Smooth flat philtrum (the groove between the nose and upper lip)
- Short palpebral fissure (short horizontal distance from one side of the eye to the other)
- Learning disability
- Behavioural difficulties
- Hearing and vision problems
- Cerebral palsy
- Cardiac malformations
Which high risk groups should be given 5mg folic acid?
- Women taking anti-epileptic drugs
- Previous baby with neural tube defects or FHx of NTD
- Obesity with BMI over 30
- Diabetes
- Sickle cell disease
- Thalassemia
- Malabsorption disorders (e.g. Crohn’s disease, coeliac)
- Those taking folate antagonist drugs (HIV anti-retroviral drugs, methotrexate, sulphonamides)
Describe some common problems in pregnancy
- Reduced foetal movements.
- N+V.
- Heartburn.
- Constipation.
Low birth weight is defined as…
< 2.5kg (5.5lb)
What is the average birth weight?
3.5kg (7.7lb)
Macrosomia is a birth weight of…
> 4.5kg (9.9lb)
Why might there be an issue measuring SFH?
Large fibroids, multiple pregnancy or BMI > 35.
Which trimester are miscarriages most common?
T1
Which drugs are contraindicated in breastfeeding?
LAMBAST + 6C’s
L - Lithium
A - Aspirin
M - Methotrexate
B - Benzodiazepines
A - Amiodarone
S - Sulphonylureas
T - Tetracycline
6’Cs - Carbimazole, Ciprofloxacin, Chloramphenicol, Cytotoxics, Clozapine, Codeine
Why are tetracyclines contraindicated in breastfeeding?
Tooth discolouration in infants.
Why is chloramphenicol contraindicated in breastfeeding?
Grey baby syndrome.
Why is ciprofloxacin contraindicated in breastfeeding?
Arthropathy in infants.
Does placenta praevia usually present with pain?
No
What is the investigation of choice for placenta praevia?
Transvaginal US.
Define puerperal psychosis
Acute onset of a manic or psychotic episode shortly after childbirth.
What are the indications for 5mg folic acid?
Take MORE Folic acid (5mg) if:
M - Metabolic disease (diabetes or Coeliac)
O - Obesity
R - Relative or personal Hx of NTDs
E- Epilepsy (taking antiepileptic medications)
+ Sickle Cell and Thalassaemia
What prophylactic antibiotics should be given for PPROM?
10 days erythromycin
In males and females how long should methotrexate be stopped for before conception?
6 months
Which SSRIs are safe to use in breastfeeding women?
Sertraline or paroxetine
Management of perineal tears
- First degree: conservative management, no repair required.
- Second degree: suturing on the ward.
- Third/fourth degree: repair in theatre.
In the combined test, how is Down’s syndrome differentiated from Edward and Patau syndrome?
- Down’s - high β-hCG
- Edward/Patau - lower β-hCG
If a pregnant women is not immune to rubella, when should the MMR vaccine be offered?
In the postnatal period.
If the Bishop score is ≤ 6, what is the preferred method of induction?
Vaginal prostaglandins or oral misoprostol.
If the Bishop score is > 6, what is the preferred method of induction?
Amniotomy and an intravenous oxytocin infusion.
Describe the interpretation of the Bishop score
- < 5 indicates that labour is unlikely to start without induction.
- ≥ 8 indicates that the cervix is ripe, or ‘favourable’ - there is a high chance of spontaneous labour, or response to interventions made to induce labour.
Name an absolute contraindication for induction of labour
Previous classical Caesarean section.
How can you distinguish between a mass representing a tubal ectopic pregnancy vs the CL, on US?
- Ectopic moves separately to the ovary.
- CL moves with the ovary.
In an intrauterine pregnancy, how much will hCG rise by in 48 hours?
Doubled
What level of hCG should a pregnancy be visible on US scan?
> 1500 IU/L
Symptoms of a miscarriage
Vaginal bleeding and abdominal/pelvic pain.
When can foetal heart beat be detected on transvaginal US?
5.5-6 weeks gestation OR CRL 7mm or more.
What is a key complication of ERPC?
Endometritis (infection of endometrium).
Define recurrent miscarriage
3 or more consecutive miscarriages.
List the causes of recurrent miscarriage
- Idiopathic
- Antiphospholipid syndrome
- Hereditary thrombophilias
- Uterine abnormalities e.g. fibroids, Asherman’s syndrome, septate uterus.
- Genetics
- Chronic histiocytic intervillositis
- Diabetes, untreated thyroid disease, PCOS and SLE
How would you reduce the risk of miscarriage in patients with antiphospholipid syndrome?
- Low dose aspirin
- LMWH
How long should magnesium sulphate be continued for in high risk severe pre-eclampsia or eclampsia?
24 hours after delivery or 24 hours after last seizure.
Describe the normal laboratory findings in pregnancy
- Reduced urea
- Reduced creatinine
- Increased urinary protein loss
- Reduced Hb
- Normal/reduced platelets
Is weight loss in babies after the first few days after birth normal?
Yes, weight loss between 7-10% in the first few days is normal and most babies return to their birth weight within 2 weeks of life.
What should be done if a breastfed baby loses > 10% of birth weight in the first week of life?
Referral to a midwife-led breastfeeding clinic.
Diagnosis of preterm prelabour rupture of membranes (PPROM)?
- Pooling of amniotic fluid in vagina on sterile speculum examination.
- If amniotic fluid not seen, IGF binding protein-1 or placental alpha-microglobin-1 (e.g. AmniSure) testing indicated.
When should corticosteroids be offered?
To women between 24 and 34 weeks gestation in whom imminent preterm birth is anticipated. In order to mature foetal lungs and reduce respiratory distress syndrome. Example: 2 doses of IM betamethasone, 24 hrs apart.
What is the first-line medication for pregnancy-induced hypertension?
Labetalol
Define pregnancy-induced hypertension (gestational hypertension)
New-onset hypertension after 20 weeks gestation in a previously normotensive women without evidence of significant proteinuria (< 30mg/mmol).
What is the first-line surgical intervention in postpartum haemorrhage if mechanical and medical measures fail?
Intrauterine balloon tamponade (Bakri catheter).
A 36-year-old multiparous women is in advanced labour at 37 weeks gestation. An ultrasound confirms a breech presentation. She is fully dilated and has been pushing for one and a half hours, however the buttocks are still not visible. How should this situation be managed?
Caesarean section
Is aspirin safe to use whilst breastfeeding?
No, aspirin is contraindicated in breastfeeding due to its association with Reye’s syndrome.
Treatment for pregnant women <= 20 weeks gestation that are not immune to varicella, who get exposed to chickenpox?
Varicella-zoster immunoglobulin.
Treatment for pregnant women > 20 weeks gestation that are not immune to varicella, but have been exposed or present within 24hrs of rash onset?
Antivirals e.g. aciclovir.
Treatment for babies born to mothers who are infected with Hep B?
Vaccination and Hep B immunoglobulin.
Which placenta abnormality is associated with IVF?
Placenta praevia.
What investigations should be performed when there are late decelerations on CTG?
Foetal blood sampling - to assess for foetal hypoxia and acidosis.
What range is the normal foetal HR?
110-160 bpm
What does late decelerations on CTG indicate?
Foetal distress e.g. asphyxia or placental insufficiency.
What does variable decelerations on CTG indicate?
May indicate cord compression.
Define lochia
Passing vaginal discharge containing blood, mucous and uterine tissue, which can continue for 6 weeks following childbirth.
Reduced foetal movements can indicate what?
Foetal distress and hypoxia.
Stillbirth and restricted growth.
At what gestation would referral to the maternal foetal medicine unit be made if a mother hasn’t felt any foetal movements yet?
24 weeks
How would you investigate reduced foetal movements?
- Handheld Doppler to confirm foetal heartbeat, then CTG to monitor to HR.
- US scan if no foetal heartbeat.
First-line treatment for magnesium sulphate induced respiratory depression?
Calcium gluconate.
Should serum ferritin levels be checked when a pregnant patient has a Hb < 110g/L?
No not routinely - NICE guidelines state that Hb < 110g/L in T1 should begin iron supplementation. In T2&3 serum ferritin levels fall independently of iron stores and are therefore unreliable.
Raised levels of maternal serum AFP produced by the developing foetus suggests…
- NTD.
- Abdominal wall defects.
- Multiple pregnancy.
Low levels of maternal serum AFP produced by the developing foetus suggests…
- Down’s syndrome.
- Edwards syndrome.
- Maternal diabetes.
- Maternal obesity.
Is epilepsy medication contra-indicated in breastfeeding?
No all anti-epileptics are safe in breastfeeding, except barbiturates.
What position should the patient be in with an umbilical cord prolapse?
On all fours or the left lateral position.
Name a cause of visual impairment in babies born before 32 weeks gestation
Retinopathy of prematurity.
List some contraindications for a planned vaginal birth after caesarean (VBAC)
- Previous vertical (classical) caesarean scars.
- Previous uterine rupture.
- Placenta praevia.
What is the most frequent cause of severe early-onset (< 7 days) infection in newborn infants?
Group B streptococcus infection.
List the complications of an abortion
- Bleeding.
- Infection.
- Pain.
- Failure.
- Damage to cervix and uterus.