Does the choice of anticoagulation strategy improve maternal and fetal outcomes in pregnant women with mechanical heart valves?
In pregnant women with mechanical heart valves, there is a trade-off between maternal and fetal outcomes, with VKAs minimizing maternal complications and LMWH maximizing livebirths.
VKAs are associated with fewest maternal complications but also with fewest livebirths. Sequential treatment does not eliminate anticoagulant-related foetal/neonatal adverse events. LMWH is associated with the highest number of livebirths. The safety of UFH throughout pregnancy and first-trimester warfarin ≤ 5 mg/day remains unconfirmed.
D’Souza et al. (2017) studied this question.