The Changes in Doppler Indices of Fetal Ductus Venosus and Umbilical Artery After Amnioinfusion for Women With Preterm Premature Rupture of Membranes Before 26 Weeks' Gestation

Objective: To investigate the changes in Doppler indices of the fetal ductus venosus (DV) and umbilical artery (UMA) after amnioinfusion in pregnant women with preterm premature rupture of membranes (pPROM). Pregnancies with pPROM and severe oligohydramnios cause sequelae in newborns and mothers. Materials and Methods: This cross-sectional study included a group of 25 patients with pPROM before 26 weeks' gestation. Color Doppler imaging was used to measure the impedance index and quantitative blood flow in the DV and systolic/diastolic ratio (S/D) of the UMA before and 30 minutes after the end of amnioinfusion. The following velocity parameters were measured: (1) DV peak systolic velocity; (2) DV time-averaged velocity; (3) DV maximum forward velocity during atrial contraction; (4) DV S/D; (5) DV pulsatility index (PI); (6) DV Pourcelot's resistance index (RI); (7) fetal heart rate; and (8) UMA S/D. Results: Twenty-one of the 25 patients underwent a total of 27 amnioinfusions. The mean PI and RI of the DV, and S/D of the DV and UMA decreased significantly after amnioinfusion (PI, 0.75 ± 0.24 vs. 0.60 ± 0.18, p = 0.009; RI, 0.60 ± 0.15 vs. 0.50 ± 0.13; DV S/D, 3.07 ± 1.81 vs. 2.13 ± 0.66, p = 0.008; UMA S/D, 3.58 ± 0.87 vs. 2.88 ± 0.62, p = 0.001). Conclusion: Amnioinfusion increases the space for the fetuses and reduces the impedance of the fetoplacental circulation. Improvements in DV and UMA flow may benefit fetuses suffering severe oligohydramnios in mid-pregnancy.