Mechanical heart valves and pregnancy: Issues surrounding anticoagulation. Experience from two obstetric cardiac centres.

BACKGROUND

Pregnant women with mechanical heart valves are at significant risk of obstetric/cardiac complications. This study compares the anticoagulation management in two obstetric cardiac centres.

METHODS

Retrospective case-note review from Chelsea and Westminster/Royal Brompton Hospitals (CR) and Erasmus Medical Centre (EMC). Main outcome measure was mechanical heart valve thrombosis.

RESULTS

Nineteen pregnancies from CR and 25 pregnancies from EMC were included. Most women were on low-molecular-weight heparin (LMWH) throughout pregnancy at CR, whereas at EMC most had LMWH in the first trimester and vitamin K antagonists in subsequent trimesters. Peak anti-factor Xa were performed monthly at CR, levels 0.39-1.51 IU/mL (mean 0.82 IU/mL). Anticoagulation management peri-partum was inconsistent. Delivery was mainly by caesarean section at CR (74%) and vaginal delivery at EMC (64%). No maternal deaths and only one mechanical heart valve thrombosis at CR. Two mechanical heart valve thromboses and one maternal death at EMC.

CONCLUSION

Peri-partum anticoagulation strategies, anticoagulation monitoring and mode of delivery inconsistencies reported.