The common prothrombotic factors in nulliparous women do not compromise blood flow in the feto-maternal circulation and are not associated with preeclampsia or intrauterine growth restriction.

OBJECTIVE: In this study we evaluated the associations between common prothrombotic factors and increased blood flow resistance in the feto-maternal circulation, intrauterine growth restriction, small for gestational age, or preeclampsia.

STUDY DESIGN: A prospective study was conducted in healthy nulliparous women with spontaneous singleton pregnancy. Blood was tested for the common prothrombotic factors, i.e., factor V Leiden, factor II G20210A, methylenetetrahydrofolate reductase C677T, anticardiolipin, and lupus anticoagulant. Blood flow resistance in the uterine, placental, and umbilical arteries were assessed by multigate Doppler and compared between women with and without prothrombotic factors. The maternal, fetal, and neonatal clinical courses were also compared among these subgroups.

RESULTS: Prothrombotic factors were detected in 191 of 637 (30%) subjects. No significant difference in resistance to blood flow in the feto-maternal unit was discernible between women with and without prothrombotic factors. Pregnancy-induced hypertension or preeclampsia occurred in 10 of 191 (5.2%) and in 19 of 446 (4.3%) of women with and without a prothrombotic factor respectively ( P = .59). Intrauterine growth restriction was detected at 31 weeks in 13 of 164 (7.9%) and in 42 of 377 (11.1%) fetuses of women with and without a prothrombotic factor ( P = .26), and small for gestational age at delivery was observed in 19 of 187 (10.2%) and in 41 of 413 (9.9%) of mothers with and without prothrombotic markers, respectively.

CONCLUSION: The presence of prothrombotic factors in healthy nulliparous women does not compromise blood flow in the feto-maternal unit, nor is it associated with preeclampsia, intrauterine growth restriction, or small for gestational age .