Early Prophylactic Enoxaparin for the Prevention of Preeclampsia and Intrauterine Growth Restriction: A Randomized Trial.

BACKGROUND: Preeclampsia (PE) and intrauterine growth restriction (IUGR) are major causes of maternal and perinatal morbidity and mortality. Previous studies have shown that intervention with low-dose aspirin resulted in a reduction in the occurrence of preterm PE. However, no data are currently available on the effect of low-molecular-weight heparin (LMWH) for the prevention of pregnancy complications in women enrolled at first trimester screening. OBJECTIVE: We aimed to assess the effectiveness of LMWH in the prevention of PE, IUGR, fetal death, and abruptio placentae in women classified as high risk based on their medical history and in women selected by first trimester screening of PE. Study -Design: This was a multicenter, randomized, open-label, parallel controlled trial in women without thrombophilia between 6.0 and 15.6 weeks of gestation. Inclusion criteria were severe PE or IUGR before 34 weeks of gestation and/or abruptio placentae or unexplained intrauterine death in a previous pregnancy; uterine artery mean pulsatility index Doppler >95th percentile and/or positive first trimester screening for PE. Pregnant women were randomly assigned to receive no intervention or LMWH until the 36th week of gestation. The primary composite outcome consisted of 1 or more of the following: development of PE, IUGR, abruptio placentae, and intrauterine fetal death. RESULTS: A total of 278 pregnant women were randomly allocated to receive LMWH (n = 134) or no intervention (n = 144). Overall, 115 (41%) women experienced placental insufficiency complications, with no significant differences between the 2 arms: 50/144 (34.7%) in the LMWH arm and 43/134 (32%) in the control arm (p = 0.64, OR: 1.13, 95% CI: 0.68-1.85). CONCLUSION: LMWH did not reduce the incidence of placenta-mediated complications either in women with previous adverse obstetric history without thrombophilia or in women selected by first trimester screening for PE. Based on these results, we cannot recommend the use of LMWH alone in women at risk of placental complications.

Role of 3-dimensional power Doppler sonography in differentiating pregnant women with threatened preterm labor from those with an asymptomatic short cervix.

OBJECTIVES: To compare cervical volumes and vascularization indices using 3-dimensional power Doppler sonography among singleton pregnancies with threatened preterm labor and an asymptomatic short cervix. METHODS: Three hundred asymptomatic healthy pregnant women between 24 and 34.6 gestational weeks were prospectively scanned for cervical length. If cervical length was short, defined as below the 10th percentile for gestational age, the cervical volume and vascularization indices (vascularization index [VI], vascularization-flow index [VFI], and flow index [FI]) were measured. Women receiving any treatment for preterm delivery prevention were excluded. During this period, the same sonographic parameters were measured among patients with threatened preterm labor admitted to our institution during the first 24 hours after admission. Multiple pregnancies and fetal or maternal pathologic conditions, were exclusion criteria. Data on body mass index, maternal age, smoking, parity, family history of preterm birth, mother who was born preterm, and previous preterm birth among the pregnant women were recorded. Sonographic and medical history parameters were compared between the two groups. RESULTS: Twenty-nine asymptomatic healthy women (9.6%) had a short cervix. Additionally, 71 pregnancies with threatened preterm labor were scanned. There were no statistically significant differences between the groups in medical history parameters or cervical length. The cervical volume was smaller in threatened preterm cases (12.90 versus 17.168 cm(3); P = .005). The VI and VFI were lower in women with an asymptomatic short cervix (VI, 4.369% versus 15.939%; P < .001; VFI, 1.514 versus 4.878; P < .001). The FI was higher in the short cervix group (33.581 versus 30.311; P = .006). CONCLUSIONS: Three-dimensional transvaginal sonography reveals differences in cervical volume and vascularization indices between pregnancies with an asymptomatic short cervix and cases with threatened preterm labor, although cervical length is similar in both groups.