Evaluation of Progesterone Effects on Fetal Doppler Velocimetry

Background Progesterone is a smooth muscle relaxant and also has a vasodilator effect on human placental arteries and veins. Objectives The aim of this study was to evaluate the effect of progesterone therapy on fetal Doppler velocimetry in intrauterine growth retardation (IUGR) and preterm fetuses. Methods Thirty pregnant females with IUGR and thirty pregnant females with threatened preterm labor at 28 to 37 weeks of gestation were enrolled in the clinical trial study. Fetal Doppler velocimetry was investigated before, 24 hours and two weeks after progesterone therapy. Seven patients with IUGR and 9 patients with preterm labor were excluded from the study before completion of the survey due to the termination of pregnancy. Results Following progesterone treatment, middle cerberal arterypulsatility index (MCA_PI) significantly decreased after 24 hours in patients with IUGR and after two weeks in patients with preterm labor (P < 0.001). There was not a statistically significant decrease in the pulsatility index of the fetal umbilical artery (UmA) after 24 hours in the IUGR fetuses (P = 0.18). Umbilical artery pulsatility index (UmA_PI) significantly decreased after two weeks in IUGR fetuses (P < 0.004). Conclusions Progesterone led to a reduction in the MCA_PI and UmA_PI in IUGR and preterm fetuses. Vasodilatory effect of progesterone on the umbilical artery is mediated by multiple doses in IUGR fetuses.