Three-Dimensional Angiogenic Evaluation of the Effect of Mifepristone in Early Gestation: Pilot Study

Abstract

Mifepristone (RU486) it is known as an effective abortifacient and postcoital contraceptive method, whose mechanism is not yet known. We carried on a pilot study with the aim of determining the effect that Mifepristone could have in utero-placental vascular compartment during the first trimester of pregnancy compared with placebo. This is a randomized, double-blind, placebo-controlled research. We randomly assigned to two groups patients requesting pregnancy termination with a gestational age between 9th and 11st weeks: Group A receiving placebo and Group B receiving RU. With transvaginal ultrasound tridimensional probe we measured at an initial time (t1) and then 4 hours after administration of Mifepristone or placebo (t2) Doppler parameters: uterine arteries mean Resistance Index, spiral arteries Resistance Index, intervillous flow, umbilical Resistance Index and tridimensional vascular settings and the placental volume. We observed how Mifepristone shows an immediate selective hemodynamic effect in trophoblastic tissue in the first hours of administration. A significant decrease in spiral arteries pulsatility index was demonstrated, without modifying uterine maternal and fetal territories or the other studied parameters. Angiopower 3D evaluation of the interface maternal fetal is complex and encourages to carry further investigations carry further investigations.