Objective This study was carried out to determine the
maternal (including thromboembolic and hemorrhagic
complications) and fetal outcomes (including miscarriage,
stillbirth, baby death, and live birth) in women with mechanical
heart valves managed with therapeutic doses of
unfractionated heparin (UFH) versus enoxaparin during
pregnancy.
Methods This is a prospective comparative, nonrandomized
study. Pregnant women with mechanical heart valves
presenting to high-risk pregnancy unit of Benha University
Hospital, Egypt were treated with UFH 15,000 U/12 h
versus enoxaparin (Clexane) 1 mg/kg SC/12 h during
pregnancy and the results were analyzed.
Results 40 pregnant women were included in the study.
In 20 pregnant women, anticoagulation was with UFH, and
20 pregnant women received enoxaparin. One (3 %)
thrombotic complication occurred with enoxaparin treatment.
Noncompliance or subtherapeutic levels contributed
to this outcome in this case. Antenatal hemorrhage occurred
in 4 (10 %) and postpartum hemorrhagic complications
in 5 (12.5 %) pregnancies. Of the 32 pregnant
women who continued after 20 weeks’ gestation, 100 %
(17/17) of the women taking predominantly UFH had a
surviving infant compared with 93 % (14/15) of the women
taking primarily enoxaparin (p = 0.25). One intrauterine
fetal death occurred in the enoxaparin group. There was no
significant difference in the live birth rates between the two
groups (p = 0.31).
Conclusions Compliance with therapeutic dose of UFH
during pregnancy in women with mechanical heart valves
is associated with a low risk of valve thrombosis and
good fetal outcomes, but meticulous monitoring is
essential