Utero-placental perfusion Doppler indices in growth restricted fetuses: effect of sildenafil citrate

Abstract

Objective: To assess efficacy and tolerability of sildenafil citrate on utero-placental blood flow and fetal growth in pregnancies complicated by fetal growth restriction (FGR).

Methods: From March 2015, a randomized controlled trial of 54 patients at 24 weeks or more complicated by FGR and abnormal Doppler indices were randomly allocated 1:1 into an intervention arm (receive sildenafil citrate, 50 mg) or a control arm (receive placebo). The primary outcomes were changes occurred in the Doppler parameters 2 h following drug administration.

Results: Baseline characteristics were similar between groups. Significant difference was observed in the Delta uterine and umbilical Doppler indices among sildenafil group as compared to placebo group (p < 0.001). Middle cerebral Doppler indices, however, decreased significantly after sildenafil, which could be the result of shifting more blood to improve the utero-placental perfusion. No difference regarding Delta cerebro-placental ratio among both groups (p = 0.979). Sildenafil was also associated with pregnancy prolongation (p = .0001), increased gestational age at delivery (p = .004), improved neonatal weight (p = .0001), and less admission to neonatal intensive care unit (p = .03). No adverse effects reported in both treatment arms.

Conclusion: Sildenafil citrate, by its vasodilator effect, can improve utero-placental blood flow in pregnancies complicated by FGR and abnormal Doppler.

Clinical trial: gov Registry: NCT02362399.

Keywords: Fetal growth restriction; middle cerebral artery Doppler; sildenafil citrate; umbilical artery Doppler; uterine artery Doppler.