Obstetrics Flashcards
Gravidity vs parity?
G = number of pregnancies
P = number of births after 24+0 weeks
Trimesters of pregnancy?
First trimester = weeks 0-13
Second trimester = weeks 14-26
Third trimester = weeks 27-40
Types of foetal lie?
Longitudinal (~99.7%)
Transverse
Oblique
Management of transverse lie or Breech presentation?
< 36 weeks = advise should self-resolve
> 36 weeks = external cephalic version (ECV) or elective C-section
Causes of antenatal haemorrhage?
Placenta praevia
Placental abruption
Vasa praevia
Miscarriage
Ectopic pregnancy
Molar pregnancy
Placenta praevia vs placenta accreta?
Praevia = low-lying placenta
Accreta = placenta attached to myometrium
Features, investigation and management of placenta praevia?
Painless vaginal bleeding
Non-tender uterus
Foetal trace normal
Investigation = usually identified at anomaly scan, TVUS
Management = elective or emergency C-section (acute bleed)
When should women with a low-lying placenta be re-scanned?
32 weeks
Features and management of vasa praevia?
Painless vaginal bleeding
Rupture of membranes
Non-tender uterus
Foetal bradycardia or death
Management = emergency C-section
Features and management of placental abruption?
Painful vaginal bleeding
Tender, tense uterus
Foetal distress
PMH trauma or injury
Management = emergency C-section (foetal distress), observe or induced vaginal birth (no foetal distress)
Features, investigation and management of an ectopic pregnancy?
Painful vaginal bleeding
Recent amenorrhoea
Dizziness, syncope, shock
Investigation = TVUS
Management = expectant management (< 35mm, asymptomatic) or methotrexate (< 35mm, symptomatic), salpingectomy/salpingotomy (> 35mm, foetal heartbeat, bHCG > 5000)
Features, investigation and management of a molar pregnancy?
Painless vaginal bleeding
Large and bulky uterus
Abnormally high hCG
Hyperemesis gravidarum
Investigation = TVUS (“snowstorm sign”)
Management = suction or surgical curettage
Types of miscarriage and features?
Threatened = painless bleeding, os closed
Delayed = painless bleeding, dead foetus in sac, os closed
Inevitable = painful and heavy bleeding, os open
Incomplete = remnants left behind, os open
Management of miscarriage?
1st line = wait 7-14 days
2nd line = vaginal misoprostol
3rd line = vacuum aspiration or surgical management
Maximum gestation eligible for TOP?
24 weeks
Medical vs surgical management of TOP?
Medical = mifepristone (anti-progestogen) + misoprostol (prostaglandin) 48 hours later
Surgical = vacuum evacuation or D&E
Gestation of booking visit, early scan, Down’s screening, anomaly scan, anti-D injections for Rh -ve women?
Booking = 8-12 weeks
Early scan and Down’s screening = 10-13+6 weeks
Anomaly = 18-20+6 weeks
Anti-D = 28 weeks (first dose), 34 weeks (second dose)
Diseases screened for at the booking appointment?
HIV
Syphillis
Hepatitis B
Monozygotic vs dizygotic twins?
Monozygotic (“identical”) = one fertilised ova split into two
Dizygotic (“non-identical”) = two separate ova fertilised at same time
Lifestyle guidance for pregnancy?
- Folic acid from before conception to 12 weeks
- Aspirin from 12 weeks if at risk of pre-eclampsia
- Vitamin D during pregnancy and breastfeeding
- Low vitamin A intake e.g. liver
- Should not drink or smoke
- Avoid air travel after 37 weeks (singleton) or after 32 weeks (multiple)
NICE criteria for requiring iron supplementation in pregnancy?
First trimester = < 110g/L
Second and third trimester = < 105g/L
Postpartum = < 100g/L
Measuring the SFH?
- From pubic bone to fundus
- After 20 weeks should be within 2cm of gestational age e.g. 24 weeks = 22-26cm
Down’s syndrome screening investigations and features?
All 3 of:
→ nuchal translucency measurement
→ serum bHCG
→ pregnancy-associated plasma protein A (PAPP-A)
↑ bHCG, ↓ PAPP-A, thickened nuchal translucency
Management of women with a “high” risk of a foetus with Down’s syndrome?
Offer second screening test:
→ NIPT e.g. cffDNA
→ amniocentesis or CVS
Oligohydramnios vs polyhydramnios?
Oligo = reduced amniotic fluid
Poly = increased amniotic fluid
Features and management of pre-eclampsia?
Triad of:
→ new hypertension > 20 weeks gestation
→ proteinuria
→ other organ involvement e.g. liver disease, headaches, visual disturbances, epigastric pain
Management = labetalol (1st line), nifedipine or hydralazine (2nd line)
Management of hypertension in pregnancy?
1st line = labetalol
2nd line = nifedipine or hydralazine
Feature and management of eclampsia?
Seizures
Management = magnesium sulphate
How long should magnesium sulphate be given in eclampsia?
Until 24 hours post-seizure or post-delivery
Management of magnesium sulphate induced respiratory depression?
Calcium gluconate
Safest anti-epileptics during pregnancy?
Lamotrigine
Levetiracetam
Features and management of HELLP syndrome?
Haemolysis
Elevated liver enzymes
Low platelet count
Management = urgent delivery
Features and management of hyperemesis gravidarum?
Frequent N&V
Ketonuria
Dehydration
Weight loss
High beta-hCG
Management = cyclizine or promethazine (long term), admission + IV saline with K+ (acute)
Complications of prematurity?
Increased risk of mortality
Respiratory distress
Chronic lung disease
Intraventricular haemorrhage
Necrotising entercolitis
Retinopathy of prematurity
Hypothermia, jaundice, infection
C-section categories?
Cat 1 = immediate threat to life of mother and/or baby, delivery within 30 mins
Cat 2 = maternal or foetal distress which is not immediately life-threatening, delivery within 75 mins
Cat 3 = mother and baby stable but delivery required
Cat 4 = elective C-section
Vaginal birth after C-section success rate and contraindication?
70-75% women have a successful vaginal birth
Contraindicated if PMH uterine rupture or classic C-section (longitudinal)
5 key features when assessing CTG?
Contractions
Baseline rate (foetal HR)
Variability (foetal HR)
Accelerations/decelerations (foetal HR)
When do foetal movements first occur?
Prim = 18-20 weeks
Multi = 16-18 weeks
Investigations for RFM?
Doppler scan
Abdominal USS
Investigation and criteria for gestational diabetes?
OGTT
→ fasting ≥ 5.6
→ 2-hour OGTT ≥ 7.8
Management of gestational diabetes (no PMH diabetes)?
Glucose < 7 = lifestyle modifications (1st line), short-acting insulin (2nd line)
Glucose ≥ 7 or foetal complications = short-acting insulin
Offer C-section at term e.g. 39 weeks
Management of gestational diabetes (PMH diabetes)?
Stop oral medication apart from metformin
Commence short-acting insulin
Management of VZV exposure in pregnancy?
Check VZV antibodies
≤ 20 weeks and not immune = VZIG
> 20 weeks and not immune = VZIG or aciclovir 7-14 days post-exposure
Management of group B strep infection in pregnancy?
Prophylactic benzylpenicillin if:
→ previous pregnancy with GBS
→ positive swab
→ preterm labour
→ pyrexia during labour
Investigations for baby born to a Rh -ve mother?
Cord blood taken at delivery
→ FBC, Coombs and ABO group
Investigations of preterm rupture of membranes?
1st line = speculum exam
2nd line = fluid PAMG-1 or insulin-like growth factor binding protein-1
Management of preterm rupture of membranes?
Admission
Oral erythromycin (chorioamnionitis prophylaxis)
Antenatal corticosteroids (NRDS prophylaxis)
Stages of labour?
Stage 1 = onset of true labour to fully dilated cervix
→ latent = 0-3cm
→ active = 3-10cm
Stage 2 = from full dilation to foetal delivery
Stage 3 = from foetal to placental delivery
Score used to assess if IOL needed and interpretation?
Bishop score
< 5 = labour unlikely to start without induction
≥ 8 = ripe cervix with low need for induction
Options for IOL?
Membrane sweep before:
→ Bishop ≤ 6 = vaginal prostaglandin or oral misoprostol
→ Bishop > 6 = amniotomy + IV oxytocin
Types of perineal tear and management?
1st degree = skin torn (no repair)
2nd degree = perineal muscle torn (suturing on ward)
3rd degree = anal sphincter torn (theatre repair)
4th degree = rectum torn (theatre repair)
Management of shoulder dystocia?
Urgent senior help
McRobert’s manoeuvre
Main risk factor for umbilical cord prolapse?
Artificial rupture of membranes
Management of umbilical cord prolapse?
Push foetus back into uterus
Keep cord warm and moist
Fill bladder with 500ml
Get mum on all 4s
Tocolytics to stop contractions
Definitive management = C-section
Tocolytic examples?
Indomethacin
Nifedipine
Magnesium sulphate
Terbutaline
Most common cause of puerperal pyrexia and management?
Endometritis
Management = admission + IV antibiotics
Causes of primary vs secondary PPH?
Primary (< 24 hours):
→ tone (atony = most common PPH cause)
→ trauma
→ tissue
→ thrombin
Secondary (24 hours-6 weeks):
→ tissue
→ endometritis
Management of PPH?
ABCDE
Rub the uterus
Drugs = oxytocin/syntocinon (1st line), ergometrine, carboprost
Surgery = balloon tamponate, ligation, hysterectomy
Anticoagulant of choice in pregnancy?
Low molecular weight heparin
Duration of maternal LMWH thromboprophylaxis?
Until 6 weeks post-partum
