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................................................................................................................................................................ threatened. The best period for surgery is between the 13th and 28th weeks. With full maternal and foetal monitoring and attention to cardiopulmonary bypass, particularly the use of pulsatile perfusion, the risks to both the mother and the foetus can be minimized. Gestational age has a large impact on neonatal outcome.87,88

Caesarean delivery may be considered before cardiopulmonary bypass if gestational age is >26 weeks.86 Whether or not delivery is advantageous for the baby at this gestational age depends on gender, estimated weight, prior administration of corticosteroids before delivery, and the outcome statistics of the neonatal unit concerned. When gestational age is >_28 weeks, delivery before surgery should be considered. Before surgery, a full course (two doses of betamethasone 12 mg intramuscularly 12 h apart) of corticosteroids should be administered to the mother, whenever possible. During cardiopulmonary bypass, foetal heart rate and uterine tone should be monitored, and cardiopulmonary bypass time should be minimized for better foetal outcomes.89,90

3.8 Timing and mode of delivery: risk for

mother and child A delivery plan should be made with details of induction, management of labour, delivery, and post-partum surveillance. The emotional context, psychological care, and ethical challenges should also be taken into account. This delivery plan should be widely disseminated and placed in the patient’s hand-held notes. Specific expertise and collaborative management by a pregnancy heart team in specialist centres is mandatory for all moderate- and high-risk patients.

3.8.1 Timing of delivery Induction of labour should be considered at 40 weeks of gestation in all women with cardiac disease; this reduces the risk of emergency caesarean section by 12% and the risk of stillbirth by 50% in women without heart disease, and the benefit is likely to be greater for women with heart disease91 who have higher rates of obstetric complications.92 Timing of induction will depend on cardiac status, obstetric evaluation including cervical assessment, foetal well-being, and foetal lung maturity.

3.8.2 Labour induction Both misoprostol [25 mg, prostaglandin E1 (PGE1)] or dinoprostone [1–3 mg or slow-release formulation of 10 mg (PGE2)] can be used safely to induce labour. Reassuringly, in women without heart disease, high-dose (600 mg) misoprostol has no effect on cardiac parameters,93 although there remains a theoretical risk of coronary vasospasm and arrhythmias. Dinoprostone may cause profound hypotension, but only when injected blindly into the myometrium,94 and this route of administration should be avoided. Mechanical methods such as a cervical ripening balloon might be preferable in patients where a drop in systemic vascular resistance would be detrimental.95 Artificial rupture of membranes and infusion of oxytocin can be used safely in women with heart disease. 3.8.3 Vaginal or caesarean delivery The ROPAC data show that elective caesarean section carries no maternal benefit and results in earlier delivery and lower birth weight.96 Vaginal delivery is associated with less blood loss and lower risk of infection, venous thrombosis, and embolism, and should be advised for most women. Caesarean section should be considered for obstetric indications and for patients presenting in labour on oral anticoagulants (OACs), with aggressive aortic pathology, and in acute intractable HF. Caesarean section is advised in severe forms of PH (including Eisenmenger’s syndrome).

3.8.4 Delivery in anticoagulated women (not including mechanical valve; see section 5) For women with a planned caesarean section, therapeutic low molecular weight heparin (LMWH) dosing can be simply omitted for 24 h prior to surgery. If delivery has to be performed earlier, then anti-Xa activity can guide the timing of the procedure. In high-risk women, therapeutic UFH can be restarted at 6 h post-delivery. In women at moderate or low-risk, a single prophylactic dose of LMWH-for example, in the case of enoxaparin, 20 mg if weight is <50 kg, 40 mg if 50–90 kg, and for women with a raised body mass index (BMI) 0.5 mg/kg-can be given at 6 h post-delivery, before restarting therapeutic LMWH 12 h later. If vaginal delivery is planned, moderate- and high-risk patients can be converted to an infusion of UFH with regular checks of aPTT to optimize control, and the infusion stopped at least 4–6 hours prior to insertion of regional anaesthesia or anticipated delivery. For women at low-risk, therapeutic LMWH can be omitted for 24 h prior to anticipated delivery. Anticoagulation can be restarted as above.

3.8.5 Urgent delivery on therapeutic anticoagulation Delivery in a patient taking therapeutic anticoagulation carries a highrisk of maternal haemorrhage. For UFH, protamine sulfate should be given, the exact dose depending on the mode of administration and time since the last dose of UFH (please refer to the European Medicines Agency statement: https://www.medicines.org.uk/emc/ product/8). In the case of LMWH, protamine sulfate should be given; however, not only may antifactor Xa activity remain prolonged and bleeding tendency persist,97 but the half-life of LMWH is longer and absorption after subcutaneous injection is prolonged, such that repeated doses or an infusion of protamine sulfate may be required. If the patient is on OACs, caesarean section is preferred to reduce the risk of foetal intracranial haemorrhage. Reversal of anticoagulation is better with four-factor prothrombin complex concentrate, best given as an individualized dose dependent on maternal weight, initial international normalized ratio (INR), and target INR98 than fresh frozen plasma (12–15 mL/kg),99 and should be given prior to caesarean delivery to achieve an INR <_1.5; however, none of the available algorithms have been validated in pregnant women. Vitamin K (5–10 mg i.v.) may also be given, but may take up to 8–12 h to reverse the INR and has a persistent effect making reanticoagulation more difficult. The foetus may remain anticoagulated Downloaded from academic.oup.com/eurheartj/article/39/34/3165/5078465 by guest on 07 October 2026