Eisenmenger Syndrome in Pregnancy
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Direct answer
Eisenmenger syndrome is a long-standing left-to-right shunt that has reversed to right-to-left because pulmonary vascular resistance has risen, causing cyanosis and polycythaemia. Pregnancy in this condition carries a very high risk of maternal death, commonly quoted at around 30 to 50 per cent, from pulmonary hypertensive crisis, arrhythmia, haemorrhage and thromboembolism. Counselling, contraception and termination advice on grounds of risk to life are therefore central.
What you must remember
- Shunt reversal: the original left-to-right shunt from an ASD, VSD or PDA reverses when pulmonary pressure becomes systemic, producing cyanosis.
- Maternal mortality: very high in pregnancy, commonly quoted as around 30 to 50 per cent, and the highest risk is around delivery and the early puerperium.
- Contraception: copper intrauterine device or progestogen-only methods are generally favoured, and oestrogen-containing methods are avoided because of thrombosis.
- Termination advice: the MTP Act permits termination where continuing the pregnancy endangers the woman's life, and the decision is made with a multidisciplinary team.
- Anaesthetic hazards: hypovolaemia, hypoxia, acidosis and sudden systemic vasodilation can precipitate a fatal crisis.
- Specialist care: pregnancy in a woman with established Eisenmenger syndrome should be managed in a centre with cardiology and intensive care.
- Pulmonary vasodilators: used in specialist centres, with inhaled nitric oxide sometimes given in labour, and bosentan is teratogenic.
A comparison of pre-Eisenmenger and Eisenmenger physiology
A 24-year-old with an unrepaired large VSD and rising haemoglobin attends for pregnancy counselling. Distinguishing a simple left-to-right shunt from established Eisenmenger physiology changes the advice completely, so the shunt direction and pulmonary pressure must be checked first.
| Feature | Left-to-right shunt | Eisenmenger syndrome |
|---|---|---|
| Shunt direction | Left to right | Right to left |
| Pulmonary pressure | Normal or mildly raised | Systemic or suprasystemic |
| Clinical clue | Murmur, few symptoms | Cyanosis, clubbing, polycythaemia |
| Pregnancy risk | Manageable with care | Very high maternal mortality |
| Aim of management | Monitor and treat as needed | Counsel, prevent pregnancy, plan if continued |
The table shows why the same heart defect can carry very different pregnancy risk. Once the shunt has reversed, the pulmonary circulation can no longer buffer the haemodynamic changes of pregnancy and labour. In the viva, candidates should name the sequence of shunt reversal, pulmonary hypertension and cyanosis, and explain why the same lesion behaves differently before and after reversal.
Where the exam tries to catch you
Eisenmenger questions test counselling, contraception and the logic of termination, not just the anatomy.
- Trap: "A caesarean is always safer for Eisenmenger syndrome." Correct: caesarean is performed for obstetric reasons, since surgery and anaesthesia carry their own haemodynamic risk.
- Trap: "Prescribe a combined oral contraceptive for a woman with Eisenmenger syndrome." Correct: oestrogen-containing methods are avoided because of thrombosis, so a copper IUD or progestogen-only method is preferred.
- Trap: "Termination advice is never appropriate in a cardiac patient." Correct: where pregnancy threatens life, termination on grounds of risk to life is a recognised and counselled option.
Frequently asked questions
Why is pregnancy so dangerous in Eisenmenger syndrome?
Pregnancy in Eisenmenger syndrome is dangerous because the fixed pulmonary hypertension cannot accommodate the circulatory changes of pregnancy and labour. Maternal death from pulmonary hypertensive crisis, arrhythmia, haemorrhage or thromboembolism is the main concern.
Which contraceptive is preferred in Eisenmenger syndrome?
A copper intrauterine device or a progestogen-only method is generally preferred in Eisenmenger syndrome, since oestrogen-containing contraceptives raise the risk of thrombosis. Sterilisation is also considered in some women after counselling.
Can a woman with Eisenmenger syndrome be advised termination?
Termination may be advised in Eisenmenger syndrome when continuing the pregnancy threatens the woman's life, which the MTP Act recognises. The decision is made after counselling by a multidisciplinary team, and the woman's own choice remains central.
How does Eisenmenger syndrome differ from a simple left-to-right shunt in pregnancy?
In a simple left-to-right shunt, pulmonary pressure is normal or mildly raised, whereas in Eisenmenger syndrome the shunt has reversed and pressure is systemic. Pregnancy risk is therefore manageable in the first and very high in the second.