Preparatory Mindset
Beyond GDM and hypertension, two other medical conditions deserve their own chapters because they behave differently in pregnancy: viral hepatitis (especially HBV — vertical transmission prevention is a core competency) and cardiac disease (the leading indirect cause of maternal death; pregnancy is a cardiac stress test). The exam mindset:
- Hepatitis in pregnancy: most cases are viral hepatitis (A-E) or pregnancy-specific liver disease (intrahepatic cholestasis of pregnancy, acute fatty liver of pregnancy, preeclampsia-related HELLP). The critical difference: HEV is far more severe in pregnancy (fulminant hepatitis, high mortality), while HBV management centres on preventing mother-to-child transmission (MTCT) — maternal antiviral (tenofovir) + neonatal HBIG + vaccine. Liver disease unique to pregnancy: AFLP (acute fatty liver of pregnancy) — an obstetric emergency needing delivery.
- Cardiac disease in pregnancy: blood volume ↑40-50%, cardiac output ↑30-40% — the load peaks in the third trimester and during labour/puerperium. Mitral stenosis (rheumatic) is the classic decompensating lesion; Eisenmenger syndrome, pulmonary hypertension, severe aortic stenosis, and Marfan aortopathy are contraindications to pregnancy. Management = multidisciplinary, drug adjustment (avoid warfarin in 1st trimester — teratogenic; use LMWH), and delivery planning.
Core Concepts
1. Hepatitis in pregnancy — three categories of liver disease
| Category | Examples |
|---|---|
| I. Pregnancy-specific liver disease | Intrahepatic cholestasis of pregnancy (ICP), acute fatty liver of pregnancy (AFLP), preeclampsia/HELLP liver involvement, hyperemesis gravidarum liver dysfunction |
| II. Coincidental acute liver disease | Acute viral hepatitis (A, B, C, E), drug-induced liver injury, acute cholecystitis |
| III. Chronic liver disease predating pregnancy | Chronic hepatitis B/C, autoimmune hepatitis, cirrhosis, Wilson disease |
2. Viral hepatitis in pregnancy
| Virus | Behaviour in pregnancy | Key management |
|---|---|---|
| HAV | Self-limited; no chronicity; not more severe | Supportive; hygiene; no vertical transmission risk |
| HBV | Same chronicity rates; MTCT mainly at delivery (exposure to maternal blood) | Screen all pregnant women (HBsAg); if HBsAg+ → check HBV DNA/viral load; tenofovir in 3rd trimester if viral load >200,000 IU/mL; neonatal HBIG + HBV vaccine within 12 h (reduces MTCT to <5%) |
| HCV | MTCT ~5% (higher if HIV co-infection); no vaccine | No antiviral in pregnancy routinely (DAAs not licensed); avoid invasive procedures; no breastfeeding restriction |
| HEV | Severe — fulminant hepatitis, high mortality especially 3rd trimester | Supportive; delivery if deteriorating; consider ribavirin (postpartum) — pregnancy + HEV = obstetric emergency |
| HDV | Only with HBV | Prevent HBV |
Breastfeeding: safe with HBV (neonate immunised) and HCV; not contraindicated generally.
3. Pregnancy-specific liver disease — high-yield
Intrahepatic cholestasis of pregnancy (ICP):
- Pruritus (often palms/soles, worse at night) + elevated bile acids (>10 μmol/L), ± jaundice, 3rd trimester.
- Fetal risk: sudden stillbirth (esp. bile acids >40 μmol/L) — the main concern.
- Treatment: ursodeoxycholic acid (UDCA); monitor bile acids + CTG/NST; delivery at 37-38 weeks (or earlier if severe).
Acute fatty liver of pregnancy (AFLP):
- Obstetric emergency — microvesicular fatty infiltration; 3rd trimester; nausea/vomiting, abdominal pain, jaundice, hypoglycaemia, coagulopathy, encephalopathy, ↑uric acid.
- Diagnosis: Swansea criteria; imaging (USS/CT fatty liver); exclude HELLP.
- Treatment: urgent delivery + supportive care (glucose, FFP, liver/ICU support). Maternal mortality significant if delayed.
4. Cardiac disease in pregnancy
Pregnancy cardiovascular load:
- Blood volume ↑40-50%; cardiac output ↑30-40%; HR ↑; SVR ↓ in 1st half.
- Peak load: 3rd trimester + labour (cardiac output spikes with contractions) + immediate postpartum (autotransfusion). Most decompensation occurs in these windows.
Classify by risk (mWHO class):
| Risk | Lesions |
|---|---|
| Low risk — pregnancy generally safe | Small ASD/VSD, repaired simple lesions, mild mitral stenosis, most NYHA class I |
| High risk — pregnancy contraindicated | Eisenmenger syndrome, severe pulmonary hypertension, severe aortic stenosis, Marfan with dilated aorta, severe LV dysfunction |
| Special risk | Mechanical heart valves (anticoagulation), cyanotic heart disease |
Rheumatic heart disease (common in developing regions):
- Mitral stenosis — the classic decompensating lesion: fixed obstruction + volume overload → pulmonary oedema / atrial fibrillation in pregnancy; rate control (β-blocker), diuretics, avoid tachycardia; delivery with short second stage; consider percutaneous mitral valvotomy if refractory.
- Mitral regurgitation — usually tolerated (SVR ↓ helps).
- Aortic stenosis — fixed obstruction, poor tolerance of hypotension/tachycardia — high risk, may need valve intervention before/after pregnancy.
Congenital heart disease: repaired simple lesions usually fine; Eisenmenger = cyanosis + reversal of shunt — maternal mortality 30-50%, counsel against pregnancy; termination if occurs; contraception essential.
Management plan:
- Preconception counselling — risk assessment, echo, adjust drugs (ACE-I/ARB → switch; warfarin → LMWH if 1st trimester).
- Antenatal: joint obstetric-cardiology clinic; echo; NYHA functional class monitoring; avoid anaemia and infection; high-risk → deliver in tertiary centre.
- Labour: short 2nd stage (assisted vaginal delivery), avoid fluid overload, epidural analgesia cautiously (maintain preload in MS), endocarditis prophylaxis not routine.
- Postpartum: peak decompensation window — monitor 24-72 h; thrombosis prophylaxis (LMWH) especially after C-section.
Anticoagulation in pregnancy (mechanical valves):
- 1st trimester: LMWH (or adjusted-dose warfarin avoided — teratogenic).
- 2nd/3rd trimester: warfarin (5 mg threshold) or LMWH; switch to LMWH before delivery; epidural timing per protocol.
High-Yield Points
| Topic | Must-remember |
|---|---|
| Liver disease categories | Pregnancy-specific (ICP, AFLP, HELLP) vs coincidental (viral) vs chronic |
| HEV | Severe in pregnancy — fulminant, high mortality (3rd trimester) |
| HBV MTCT | Tenofovir if VL >200,000; HBIG + vaccine within 12 h → MTCT <5% |
| HBV screening | All pregnant women — HBsAg at booking |
| ICP | Pruritus + bile acids; fetal risk = sudden stillbirth; UDCA; deliver 37-38 wk |
| AFLP | Obstetric emergency — jaundice + hypoglycaemia + coagulopathy + encephalopathy; urgent delivery |
| Cardiac load windows | 3rd trimester + labour + postpartum (autotransfusion) |
| Eisenmenger | Pregnancy contraindicated — maternal mortality 30-50% |
| Mitral stenosis | Classic decompensating rheumatic lesion (pulmonary oedema, AF) |
| Mechanical valve | LMWH 1st trimester (warfarin teratogenic); warfarin/LMWH later |
| Drugs to avoid | ACE-I/ARB (fetotoxic), warfarin (1st trimester) |
Topic Summary
Hepatitis in pregnancy: pregnancy-specific liver disease (ICP — treat with UDCA, deliver early to prevent stillbirth; AFLP — urgent delivery) vs viral hepatitis (HEV is dangerous in pregnancy; HBV — screen, tenofovir for high viral load, HBIG + vaccine for neonate). Cardiac disease: pregnancy is a volume-overload stress test, peaking in the 3rd trimester, labour, and postpartum; mitral stenosis decompensates, Eisenmenger/pulmonary hypertension contraindicate pregnancy; management is multidisciplinary with tailored anticoagulation (LMWH early) and delivery planning. The shared theme: identify the high-risk mother early, optimise her disease, and time delivery deliberately.
LMCHK OSCE Practice — Pregnant Woman with Itchy Palms
Station setup: A 27-year-old primigravida at 34 weeks presents with generalised pruritus worse at night, worst on the palms and soles, for 2 weeks. No rash. LFT: ALT 60, bile acids 45 μmol/L. BP 115/70, no proteinuria.
Candidate tasks (8 min):
- Take focused history (itch timing, family history, previous pregnancy, gallstones, hepatitis).
- Diagnose intrahepatic cholestasis of pregnancy (ICP) — pruritus + elevated bile acids, 3rd trimester, normal BP (not preeclampsia).
- Explain the fetal risk (sudden stillbirth, especially bile acids >40 μmol/L) honestly but calmly.
- Outline management: UDCA (improves pruritus ± bile acids), serial bile acids + CTG/NST monitoring, delivery planned at 37-38 weeks (or earlier if severe/rising bile acids).
- Reassure re: symptoms resolve after delivery; screen postpartum for recurrence risk in future pregnancies.
Key marking cues:
- Distinguishes ICP (pruritus + bile acids, normal BP) from preeclampsia/HELLP and viral hepatitis.
- Emphasises the fetal (not maternal) risk — stillbirth.
- Prescribes UDCA and plans early term delivery.
- Gives postpartum follow-up (resolution + recurrence risk).
Companion station — HBV-positive antenatal counselling:
A 26-year-old G1P0 at 16 weeks, HBsAg+, HBeAg+, HBV DNA 5×10⁶ IU/mL.
- Explain vertical transmission risk and prevention (tenofovir from ~28 wk if VL >200,000; neonatal HBIG within 12 h + HBV vaccine series).
- Address breastfeeding (safe once neonate immunised) and delivery mode (vaginal OK, no benefit from C-section if prophylaxis given).
- Partner screening + vaccination; family planning counselling.
- Postpartum: continue tenofovir per protocol (or stop with close monitoring); monitor LFTs.