Pregnancy Flashcards
Molar pregnancy has what appearance on ultrasound?
Snow storm appearance
What marker is used in pregnancy tests?
- beta HCG
- human chorionic gonadotrohpin
Name causes of bleeding in pregnancy
- implantation bleeding
- sub-chorionic haematoma
- cervical causes; infection, malignancy, polyp
- vaginal causes; infection, malignancy
- unrelated; haematuria, PR bleeding etc
- miscarriage
- ectopic
Describe symptoms of miscarriage
- positive urine pregnancy test
- bleeding primary symptoms (> cramping), varied amount
- period type cramps
- passed products may be brought in
- cervical shock symptoms
What are cervical shock symptoms and how are they managed?
- cramps
- nausea and vomiting
- sweating
- fainting
- resolves if product removed from cervix
- resuscitation with IV infusion, uterotonics maybe required
What are the causes of miscarriage
- embryonic abnormality
- immune cause; antiphospholipid syndrome
- infections; cytomegalovirus, rubella, toxoplasmosis, listeria
- severe emotional upsets, stress
- iatrogenic loss
- associations; heavy smoking, cocaine, alcohol misuse
- uncontrolled diabetes
Describe the pathophysiology of miscarraige
- unclear
- bleeding from placental bed or chorion causing hypoxia and villous / placental dysfunction
- this causes embryonic demise
What are the different classifications of miscarriage?
- threatened miscarriage (risk to pregnancy)
- inevitable miscarriage (pregnancy can’t be saved)
- incomplete miscarriage (part of pregnancy is lost already)
- complete miscarriage (all of pregnancy is lost, uterus is empty)
- early foetal demise or non-continuing pregnancy
- anembryonic pregnancy; no foetus, empty sac
Describe the management of miscarriage
- assessing and ensuring haemodynamic stability
- investigations; FBC, group and save, serum hCG, ultrasound, histology
- realistic but sensitive discussion
- discharge or admit
- treatment; conservative, medical, manual vacuum aspiration
- anti-D administration if surgical intervention is needed
- emotional support
Recurrent miscarriage is defined as what?
3 or more pregnancy losses
Name the common sites of ectopic pregnancy
- fallopian tube
- interstitial
- isthmic
- ampullary
- fimbrial
Describe the presentation of ectopic pregancy
- pain
- dizziness
- collapse
- shoulder tip pain
- shortness of breath
- pallor
- haemodynamic instability
- signs of peritonism
- guarding and tenderness
Name investigations for ectopic pregnancy
- FBC
- group and save
- beta HCG
- USS (transvaginal is the gold standard); empty uterus / pseudo sac, +/- mass in adenexa, free fluid pouch of douglas
Describe the management of ectopic pregnancy
- ABCDE
- surgical management (if patient acutely unwell); laparoscopic salpingectomy or salpingotomy
- medical management (if stable); methotrexate 1 or 2 doses as protocol
- conservative management
Describe the presentation of pregnancy of unknown location
- amenorrhoea
- abdominal pain
- no evidence of pregnancy in uterus, fallopian tube, cervix, csection scar or abdominal cavity
- level of hCG confirming a pregnancy circumstnace
Describe the management of pregnancy of unknown location
- follow up with progesterone levels
- medically with methotrexate if no deterioration clinically
Describe possible issues of presentation for molar pregnancy
- hyperemesis, hyperthyroidism, early onset pre-eclampsia
- varied bleeding and occasional history of passage of ‘grape like’ tissue
- fundus > dates on abdominal palpation
- rare cases; shortness of breath (due to embolisation to lungs) or seizures (metastasis to brain)
- USS can diagnose ‘snow storm appearance’
Describe the management of molar pregnancy
- surgical procedure (uterine evacuation) and tissue sent for histology to ascertain type
- in higher gestation where foetus is present in partial mole medical management can be undertaken
- registration and follow up with molar pregnancy services
- 3 centres in UK; london, sheffield, dundee
What is implantation bleeding?
- occurs when the fertilised egg implants in the endometrial lining
- timing is about 10 days post-ovulation
- bleeding is light / brownish and self limiting
- soon signs of pregnancy emerge
- occasionally mistaken as period (2 weeks post ovulation, heavier, bright red like a normal period usually)
- watchful waiting and being aware of entity
- usually settles and pregnancy continues
What is a chorionic haematoma?
Pooling of blood between endometrium and the embryo due to separation; sub-chorionic
Describe symptoms of chorionic haematoma
- bleeding
- cramping
- threatened miscarriage
- large haematomas may be a source of infection, irritability (causing cramping) and miscarriage
How is bacterial vaginosis treated in pregnancy?
- metronidazole 400mg twice daily for 7 days
- avoid alcohol during medication
- option of vaginal gel
How is chlamydia treated during pregnancy?
- erythromycin, amoxicillin
- test of cure 3 weeks late
- liaise with sexual health, include partner tracing
What is hyperemesis gravidarum?
- vomiting in the first trimester common, limited and mild
- starts as early as around time of missed period
- if excessive, protracted, altering quality of life it is called hyperemesis gravidarum
Hyperemesis gravidarum can have what effects?
- dehydration
- ketosis
- electrolyte and nutritional disbalance
- weight loss
- altered liver function (up to 50%)
- signs of malnutrition
- emotional instability, anxiety
- severe cases can cause mental health issues
What are the principles of management of hyperemesis gravidarum?
- rehydration IV, electrolyte replacement
- parenteral antiemetic
- nutritional supplement
- vitamin supplement; thiamine / pabrinex
- NG feeding, total parenteral nutrition
- steroid use in recurrent, severe cases
- thromboprophylaxis
Name medications used in the treatment of hyperemesis gravidarum
- antimetics
- first line; cyclizine (50mg orally, IM or IV 8 hourly), prochlorperazine (12.5mg IM/IV 8 hourly or 5-10mg orally 8 hourly)
- second line; metoclopramide 5-10mg IM 8 hourly
- thiamine supplement 50mg TDS / pabrinex IV
- H2 receptor blocker (ranitidine) and PPI (omperazole) safe for use in pregnancy
- steroid; oral prednisolone 40mg/ day in divided doses, tapered per effect over weeks
The fertilised ovum progressively divides and differentiates into what?
A blastocyst as it moves from site of fertilisation in the upper oviduct to the site of implantation in the uterus
What occurs 3-5 days after fertilisation?
Transport of blastocyst into the uterus
What occurs 5-8 days after fertilisation?
Blastocyst attaches to lining of uterus
What do the two parts of the blastocyst go on to develop?
- inner cells develop into embryo
- outer cells burrow into uterine wall and become placenta
What happens when the blastocyst adheres to the endometrial lining?
- cords of trophoblastic cells being to penetrate the endothelium (achieves implantation)
- advancing cords of trophoblastic cells tunnel deeper into endometrium, carving out a hole for the blastocyst
- the boundaries between cells in the advancing trophoblastic tissue disintegrate
The placenta is derived from what?
Both trophoblast and decidual tissue
Describe placental development
- trophoblast cells (chorion) differentiate into multinucleate cells (syncytiotrophoblasts) which invade decidue and break down capillaries to form cavities filled with maternal blood
- developing embryo sends capillaries to form palcental villi
- no direct contact between foetal and maternal blood, thin layer of tissue
Describe the early nutrition provisions for the embryo
- invasion of the trophoblastic cells into the decidua
- HCG signals the corpus luteum to continue secreting progesterone
- progesterone stimulates decidual cells to concentrate glycogen, proteins and lipids
The oxygen supply of the foetus with oxygen is facilitated by what three factors?
- foetal Hb; increased ability to carry O2
- higher Hb concentration in foetal blood
- bohr effect; foetal Hb can carry more oxygen in low PCO2 than in high PCO2
How does the placenta transport nutrients and waste products?
- water diffuses along its osmotic gradient
- electrolytes follow H20 (iron and Ca2+ only go from mother to child)
- glucose, passes via simplified transport
- free diffusion of fatty acids
- diffusion of waste products
Name examples of drugs that can cross the placenta
- thalidomide, carbamazepine, coumarins, tetracycline
- alcohol, nicotine, heroin, cocaine, caffeine
Human chorionic gonadotrophin (HCG) has what effects?
- prevents involution of corpus luteum (which in turn stimulates progesterone, oestrogen)
- effect on the testes of male foetus; development of sex organs
Human placental lactogen has what effects?
- produced from week 5 of pregnancy
- growth hormone like effects, protein tissue formation
- decreases insulin sensitivity in mother; more glucose for the foetus
- involved in breast development
Progesterone has what effects?
- development of decidual cells
- decreases uterus contractility
- preparation for lactation
Oestrogens have what effect?
- enlargement of uterus
- breast development
- relaxation of ligaments
Increase in cardiac output in pregnancy is due to what?
The demands of the uteroplacental circulation
Why does the cardiac output depend on body position in pregnancy?
The uterus can compress the vena cava
Describe the cardiovascular changes during pregnancy
- increased cardiac output
- heart rate increased
- bp drops during 2nd trimester, rises in 3rd trimester
- multiple pregnancy; CO increases more, BP drops more
- increased plasma volume
- increased stroke volume
- decreased peripheral vascular resistance
Describe the haematological changes during pregnancy
- plasma volume increases proportionally with cardiac output
- erythropoesis increases
- Hb is decreased by dilution
- iron requires increases; meaning iron supplements are needed
What is the definition of anaemia in pregnancy?
- first trimester Hb <110g/L
- 2nd and 3rd trimester Hb <105g/L
Describe the respiratory changes during pregnancy
- occur partly due to progesterone increase and partly because enlarging uterus interferes with lung function
- lower CO2 levels
- O2 consumption increases to meet metabolic needs
- RR increases, tidal and minute volume increases
Describe the urinary system changes during pregnancy
- GFR and renal plasma flow increases (up to 30-50%; peaks at 16-24 weeks)
- increased re-absorption of ions and water; placental steroids, aldosterone
- slight increase of urine formation
What is the average weight gain during pregnancy?
11kg
What occurs during the mothers anabolic phase?
- normal or increased sensitivity to insulin
- lower plasmatic glucose level
- lipogenesis, glycogen stores increases
- growth of breasts, uterus, weight gain
What occurs during the mothers catabolic phase?
- accelerated starvation
- maternal insulin resistance
- increased transport of nutrients through placental membrane
- lipolysis
What are the hormonal changes towards the end of pregnancy?
- uterus becomes progressively more excitable
- oestrogen:progesterone ratio alters increasing excitability; progesterone inhibits contractility while oestrogen increases contractility
- prostaglandins produced by placenta, myometrium, decidua and membranes
- oxytocin (from maternal posterior pituitary gland); increases contractions and excitability
Cervical stretching during labour causes what to be released?
Oxytocin
What are the three stages of labour?
- 1st stage; cervical dilation (8-24 hours)
- 2nd stage; passage of the foetus through birth canal (few min to 120 mins)
- 3rd stage; expulsion of placenta
What hormones are involved in producing and releasing milk?
- oestrogen; growth of ductile system
- progesterone; development of lobule alveolar system
- both of these inhibit milk production, at birth sudden drop in E and P
- prolactin stimulates milk production
- oxytocin; mild let down reflex
What are the folic acid recommendations?
- 400mcg folic acid pre-conception and first trimester
- 5mg in some cases (obese, diabetics, antiepileptics, FH)
What are the vitamin D recommendations?
- Throughout pregnancy and continuation if breast feeding
- 10 mcg/day
What foods should be avoided in pregnancy?
- soft cheese
- undercooked meat, cured meats, game
- tuna
- raw / partially cooked eggs
- pate
- liver
- vitamin and fish oil supplements
What is the commonest cause of iatrogenic prematurity?
Pre-eclampsia
What is the definition of hypertension in pregnancy?
- > 140/90 mmHg on 2 occasions
- > 160/110 mmHg once
- (>30/15 mmHg compared to first trimester BP)
What are the risks of having pre-existing hypertension during pregnancy?
- pre-eclampsia 2x risk
- foetal growth restriction
- placental abruption
Describe pregnancy induced hypertension
- second half of pregnancy
- resolves within 6 weeks of delivery
- no proteinuria or other features of pre-eclampsia -
- rate of recurrence is high
What is the triad of features of pre-eclampsia?
- hypertension
- proteinuria (>0.3g/24h or uPCR>0.3)
- oedema
- rarely all three so absence does not exclude diagnosis
What is pre-eclampsia?
- a pregnancy specific multi-system disorder with unpredictable, variable and widespread manifestations
- women may be asymptomatic at the first time of their presentation
- diffuse vascular endothelial dysfunction, widespread circulatory disturbance
What is the time scale for early and late pre-eclampsia?
- early pre eclampsia <34 weeks
- late pre-eclampsia >34 weeks
Describe the pathogenesis of pre-eclampsia
- stage 1; abnormal placental perfusion, placental ischaemia
- stage 2; maternal syndrome, an anti-angiogenic state associated with endothelial dysfunction
What is HELLP syndrome?
- associated with pre-eclampsia
- haemolysis
- elevated liver enzymes
- low platelets
What liver features can occur with pre-eclampsia?
- epigastric / right upper quadrant pain
- abnormal liver enzymes
- hepatic capsule rupture
- HELLP syndrome
Name symptoms of pre-eclampsia
- headache
- visual disturbance
- epigastric / RUQ pain
- nausea / vomiting
- rapidly progressive oedema
- considerable variation in timing, progression and order of symptoms
Name signs of pre-eclampsia
- hypertension
- proteinuria
- oedema
- abdominal tenderness
- disorientation
- small for gestational age (SGA) foetus
- intra-uterine foetal death
- hyper-reflexia / involuntary movements / clonus
Name investigations for pre-eclampsia
- urea and electrolytes
- serum urate
- liver function tests
- FBC
- coagulation screen
- urine-protein creatinine ratio
- cardiotocography
- ultrasound; foetal assessment
Name risk factors for pre-eclampsia
- maternal age >40
- maternal BMI >30
- family history
- first pregnancy
- multiple pregnancy
- previous PE
- birth interval >10 years
- molar pregnancy
- pre-existing renal disease,
- pre-existing hypertension -
- diabetes all forms
- connective tissue disease
- thrombophilias
What is the mode of action of aspirin?
- inhibits cyclo-oxygenase
- prevents TXA2 synthesis
What is low dose aspirin used for in pregnancy?
- prevention of pre-eclampsia
- used for high risk women renal, DM etc
- commence before 16 weeks
- 150mg dose
How can pre-eclampsia be predicted on ultrasound?
- maternal uterine artery doppler
- at 20-24 weeks
- notching of the artery is a sign
What drugs can be used to treat hypertension in pregnancy?
- methyldopa (centrally acting alpha agonist)
- labetalol (alpha and beta antagonist)
- nifedipine SR (Ca2+ channel antagonist)
- hydralazine and doxazocin 2nd line
How is the foetus monitored during admission for pre-eclampsia?
- foetal movements
- CTG daily
- ultrasound; biometry, amniotic fluid index, umbilical artery doppler
What are the indications for birth with a pre-eclamptic mother?
- term gestation
- inability to control BP
- rapidly deteriorating biochemistry / haematology
- eclampsia
- other crisis
- foetal compromise
Name crises in pre-eclampsia
- eclampsia
- HELLP syndrome
- pulmonary oedema
- placental abruption
- cerebral haemorrhage
- cortical blindness
- DIC
- acute renal failure
- hepatic rupture
What is eclampsia?
- tonic clonic (grand mal) seizure occuring with features of pre-eclampsia
- associated with ischaemia / vasospasm
What antihypertensives can be IV in pre-eclampsia?
- IV labetalol
- IV hydralazine
What is the seizure treatment / prophylaxis of eclampsia?
Magnesium sulphate
- loading dose; 4g IV over 5 minutes
- maintenance dose; IV infusion 1g/h
- if further seizures administer 2g Mg SO4
- if persistent seizures consider diazepam 10mg IV
What drug should be avoided in labour and birth in patients with pre-eclampsia?
Ergometrine
also caution with IV fluids
What is large for dates?
Symphyseal-fundal height >2cm larger than expected for gestational age
What are the causes of large for dates?
- wrong dates
- foetal macrosomia
- polyhydramnios
- diabetes
- multiple pregnancy
- obesity
How is foetal macrosomia diagnosed?
USS EFW >90th centile
What are the risks of foetal macrosomia?
- clinical and maternal anxiety
- labour dystocia (failure to progress in labour)
- shoulder dystocia; more with diabetes
- PPH
Describe the management of foetal macosomia
- exclude diabetes
- reassure
- conservative vs IOL vs C/S delivery
- in EFW >/= 5kg offer c/section
What is polyhydramnios?
- excess amniotic fluid
- amniotic fluid index (AFI >25cm)
- deepest pool >8cm
Name causes of polyhydramnios
maternal - diabetes foetal - anomaly; GI atresia, cardiac, tumours - monochorionic twin pregnancy - hydrops foetalis; Rh isoimmunisation - viral infection (erythrovirus B19, toxoplasmosis, CMV) - idiopathic
Name clinical features of polyhydramnios
Symptoms; - abdominal discomfort - pre labour rupture of membranes - preterm labour - cord prolapse Signs; - LFD - malpresentation - tense shiny abdomen - inability to feel foetal parts
Name investigation for polyhydramnios
- oral glucose tolerance test (OGTT)
- serology; toxoplasmosis, CMV, parvovirus
- antibody screen
- USS; foetal survey, lips, stomach
Describe management of polyhydramnios
- patient information; complications
- serial USS; growth, LV, presentation
- IOL by 40 weeks
- labour; risk of malpresentation, cord prolapse, preterm labour, PPH, neonatal examination
What are the different forms of twins?
Zygosity;
- monozygotic; splitting of a single fertilised egg
- dizygotic; fertilised of 2 ova by 2 spermatozoa
Chorionicity
- 1 or 2 placentas
- dizygotic; always DCDA
- monozygotic; dichorionic diamniotic (DCDA), monochorionic, diamniotic (MCDA), monochorionic monoamniotic (MCMA), conjoined
How can chorionicity be determined on USS?
- dichorionic diamniotic has a lambda sign
- monochorionic diamniotic has a T sign
What complications can occur in monochorionic twins?
- single foetal death
- selective growth restriction
- twin to twin transfusion syndrome
- twin anaemia-polycythaemia sequence
- abnormal dopplers
What is twin to twin transfusion syndrome?
- syndrome with artery-vein anastomoses
- donor twin perfuses the recipient twin
- olidohydramnios-polyhydramnios
What is management and complications of twin to twin transfusion syndrome?
- before 26/40; fetoscopic laser ablation
- > 26/40; amnioreduction / septostomy
- deliver 34-36/40
- complications; mortality >90% with no treatment
Describes the timings of delivery in multiple pregnancy
- DCDA twins deliver 37-38 weeks
- MCDA twins deliver after 36+0 weeks with steroids
- MCMA caesarean section
What are the effects of pregnancy on diabetes?
- increases insulin requirements
- N and V can precipitate DKA
- ketosis more common
- diabetic retinopathy worsens especially after rapid control of diabetes
- diabetic neuropathy can worsen
What is small for gestational age?
- Infant born with birth weight below 10th centile
- abdominal circumference or estimated foetal weight below 10th centile by ultrasound san
What is foetal growth restriction?
- failure to achieve genetic potential for growth, implies pathological restriction of genetic growth potential
- AC or EFW below 3rd centile or
- AC or EFW below 10th centile and evidence of placental dysfunction
Name causes of small for gestational age
Placental - infarcts - abruption - often secondary to Htx Maternal; - smoking, alcohol, drugs - height and weight - age - maternal disease Foetal; - infection (rubella, CMV, toxoplasmosa) - congenital anomalies - chromosomal abnormalities e.g. downs syndrome
How is small for gestational age diagnosed?
- ultrasound measurement of AC and calculation of EFW
- measurements plotted on centile chart
- various charts available
- some customised for maternal factors
- intergrowth 21st used in NHS tayside
Name major risk factors for SGA
- maternal age >40
- smoker
- paternal or maternal SGA
- cocaine use
- daily vigorous exercise
- previous SGA
- previous stillbirth
- chronic hypertension
- diabetes with vascular disease
- renal impairment
- APS
- low PAPP-A
- foetal echogenic bowel
- bmi >35
- known large fibroids
What is the management plan once small for gestational age is recognised?
- serial scans with umbilical doppler and liquor volume as a minimum (reduced liquor is a sign of foetal distress)
- 150mg aspirin at night from 12 weeks in women with risk factors for pre-eclampsia or uterine artery notching at anomaly scan
What should the flow of blood be in the umbilical artery?
- should always be forward flow even in maternal diastole
- this can be measured using doppler
When is magnesium sulphate offered before delivery?
- 4 hours before delivery if no foetal compromise
- offer if below 32 weeks gestation
- can protect somewhat from cerebral palsy
Describe warfarin and its effects on pregnancy
- crosses the placenta and is teratogenic
- warfarin embryopathy; midface hypoplasia, stippled chondral calcification, short proximal limbs, short phalanges, scoliosis
- risk seems to be dose dependent (>5mg/day)
- convert to LMWH by 6 weeks
Describe post-natal anticoagulation
- neither heparin nor warfarin are contraindications to breastfeeding
- commence warfarin on 5th day post partum
- anticoagulant therapy should be continued until at least 6 weeks post-natal and until at least 3 months post partum
What is obstetric cholestasis?
- disease of pregnancy, a diagnosis of exclusion
- sever pruritus (excoriations but no rash), particularly palms and soles in second half pregnancy
- very rare; dark urine, anorexia and steatorrhoea
- LFTs deranged
- recovers within 2 weeks postnatal
- investigated by liver USS, viral serology and liver autoantibodies
The booking visit occurs when?
Generally 8-12 weeks
What occurs during the booking visit?
- history
- height, weight, BP
- bloods; Hb, ABO, rhesus status and antibodies, syphilis, HIV, hep b and c, urinalysis
- ultrasound; usually secondary app. confirm viability, single or multiple pregnancy, estimate gestational age, detect any major structural anomalies, offer trisomy screening
What can be used to estimate gestational age in first trimester and in second trimester?
On scan
- 1st trimester; crown rump length
- 2nd trimester; head circumference
What usually occurs during normal antenatal appointments?
- history; physical and mental health, foetal movements
- examination; BP and urinalysis, symphysis and fundal height, lie and presentation, engagement of presenting part, foetal heart auscultation
What is placenta praevia?
- When the placenta is low lying in the uterus and covers all or part of the cervix
- if placenta is low at anomaly scan then rescan at 32 weeks
- sometimes a transvaginal scan is needed for placental site
What trisomy can be screened for in pregnancy?
- downs syndrome; T21
- edwards syndrome T18
- pataus syndrome T13
How is trisomy risk assessed in the first trimester?
- measure of skin thickness behind foetal neck using ultrasound (nuchal thickness)
- measured at 11-13+6 weeks
- combined with HCG and PAPP-A
- a value of <3.5mm would be considered normal when the CRL is between 45 and 84 mm
How is trisomy risk assessed in the second trimester?
- blood sample at 15-20 weeks
- assay of HCG and AFP, unconjugated oestradiol, inhibin A
Describe NIPT
- cell free foetal DNA testing, non-invasive prenatal testing
- it detects foetal DNA fragments in a sample taken from the mother
- detectable from about 10 weeks of pregnancy
- screening test only, NOT diagnostic