RESUMO
ObjectiveTo evaluate the efficiency of heparin on the ratio of peak systolic to least diastolic flow velocity (S/D) of umbilical artery flow velocity waveforms at second-trimester pregnancies. MethodsSixty-seven pregnant women carrying 72 fetuses (5 twins) whose fetal umbilical artery flow S/D ratios were more than the 95~th percentage were divided into study and control groups. In study group, 35 women carrying 38 fetuses were treated with heparin at a dose of 6250 U or 12 500 U + 5% glucose 500 ml intravenously per day for a mean of (3.7?2.1)days, ranging from 1 to 10 days. In control group,another 32 women with 34 fetuses were treated regularly with dextran-40 500 ml and 10% glucose 500 ml + rooted salvia 30 ml; and 10% glucose 500 ml + 654-II 20 mg for a mean of (6.8 ?2.8) days, ranging from 3 to 14 days. After treatment the S/D ratios were re-examined, and compared between two groups. ResultsThe mean of decreased S/D ratios per day in heparin group and control group was 0.37(t=3.620, P