Mechanical valve prosthesis and anticoagulation regimens in pregnancy: a tertiary centre experience.

OBJECTIVE

This study was undertaken to analyze the maternal and perinatal outcome in women with prosthetic heart valves on different anticoagulant regimens.

STUDY DESIGN

A retrospective chart review of pregnancies in 40 women with mechanical valve prostheses at a tertiary referral centre from 1997 to 2010. The main outcome measures were major maternal complications and perinatal outcome.

RESULTS

The valves replaced were mitral (67.5%), aortic (15.0%), or both (17.5%). Forty-nine pregnancies (72.1%) resulted in live births, 3(4.4%) had stillbirths, and 13(19.1%) had spontaneous abortions and 1(1.4%) underwent therapeutic abortions. The live birth rate was higher in women on heparin (78.3%) compared with those on warfarin (66.9%). There were 2 maternal deaths due to acute mitral valvular thrombosis while on acenocoumarol in the second trimester. Hemorrhagic complications occurred in 3 patients on heparin in the postpartum period, 2 of whom required transfusion. In addition one patient who was on acenocoumarol developed secondary hemorrhage.

CONCLUSION

No anticoagulant regimen can be said to be entirely safe for use during pregnancy as there is a degree of risk with each regimen. Further larger studies are needed to come up with sufficient evidence-based recommendations for the best possible management of such patients to reduce the maternal risks after mechanical heart valve replacement without compromising fetal outcome.