OG12.4 | Heart Disease in Pregnancy — Summary & Reflection

KEY TAKEAWAYS

Heart disease complicates 1–3% of pregnancies and is responsible for 10–15% of maternal deaths in India, predominantly due to rheumatic heart disease (mitral stenosis). Normal pregnancy increases cardiac output 30–50% by 28–32 weeks, heart rate, and blood volume while reducing SVR — changes that can precipitate decompensation in a diseased heart. NYHA functional classification guides risk: Class I–II are manageable with specialist care; Class III carries maternal mortality 5–15%; Class IV and Eisenmenger syndrome are contraindications to pregnancy (maternal mortality up to 50%). Investigations include ECG, echocardiography, and WHO mWHO risk stratification. Management is multidisciplinary: benzathine penicillin prophylaxis against rheumatic fever, diuretics and digoxin for heart failure and AF, LMWH anticoagulation in the first trimester and at term (warfarin second trimester for mechanical valves). Labour is preferably vaginal with assisted second stage; ergometrine is absolutely contraindicated (use slow oxytocin infusion for AMTSL). The postpartum period is high-risk due to fluid mobilisation — HDU monitoring for 24–48 hours is mandatory in NYHA III–IV. ACE inhibitors and ARBs are contraindicated in pregnancy.

REFLECT

Return to Sunita's case: mitral stenosis presenting in AF at 28 weeks. She did not have the secondary prevention that could have prevented her RHD from progressing. Think about the chain of events: an untreated Group A streptococcal pharyngitis in childhood leading to rheumatic carditis, to mitral stenosis, to an undiagnosed cardiac condition entering pregnancy, to atrial fibrillation and potential pulmonary oedema at 28 weeks. Every link in this chain represents a point of preventable intervention. As a future clinician, where in this chain will you be able to act — at the individual patient level in your antenatal clinic, or at the public health level in advocating for streptococcal pharyngitis treatment, or both? What does Sunita's case tell you about the relationship between social determinants of health and maternal mortality in India?