Low-molecular-weight heparin for thrombophilia in pregnant women

Low-molecular-weight heparin (LMWH) is the anticoagulant of choice during pregnancy because it is associated with a low incidence of osteoporosis and thrombocytopenia. Antithrombotic therapy has recently been used to prevent pregnancy loss in high-risk patients with evidence of acquired or congenital thrombophilia. The aim of the present study was to gain further information on the teratogenic potential of LMWH in this patient group.

The study population included 46 patients with a history of recurrent abortions, intrauterine fetal death or intrauterine growth restriction (IUGR) and severe early-onset preeclampsia. Patients with a history of thromboembolism or positive findings for thrombophilia were prescribed LMWH (enoxaparin sodium, 40 mg daily) in combination with low-dose aspirin (100 mg daily) in the first trimester (group 1, n=14) or the second trimester (group 2, n=17); the remaining 15 patients received low-dose aspirin alone (group 3).

No significant differences were noted between the groups in the incidence of congenital malformations or abortions, IUGR or preterm deliveries. One infant in group 1 had familial bilateral postaxial polydactyly of the hands and one in group 3 had patent ductus arteriosus.

Despite the small size of the study groups, our results support the assumption that the use of LMWH is safe, at least as a teratogenic agent, in patients with thrombophilia throughout pregnancy.