Effect of transdermal nitroglycerin compared with sildenafil citrate on Doppler indices in intrauterine growth restriction

Abstract

Objective This study aimed to compare the effect of sildenafil citrate on pulsatility index of uterine, umbilical and middle cerebral arteries to that of nitroglycerine in cases of intrauterine growth restriction (IUGR). Background IUGR is one of the most common and serious complications of pregnancy. Sildenafil citrate and nitroglycerine are emerging as potential candidates for the treatment of IUGR through improving uteroplacental blood flow. Participants and methods Ninety singleton pregnancies, with IUGR and abnormal uterine and umbilical arteries Doppler, were included in the study and randomized into three groups to receive either oral sildenafil citrate (50 mg), a transdermal nitroglycerine patch (10 mg), or placebo. Maternal mean arterial blood pressure and the pulsatility index (PI) of uterine (Ut.A), umbilical (UA) and fetal middle cerebral (MCA) arteries were measured before and two hours after application of drugs. Results A significant reduction of Ut.A-PI occurred after application of both sildenafil citrate (16.7%, P = 0.001) and nitroglycerine (18.7%, P = 0.001). UA-PI also showed a significant decrease with both sildenafil citrate (17.8%, P = 0.001) and nitroglycerine (17.03%, P = 0.001), with no significant difference between the two drugs. No changes were observed in Doppler velocimetry in the placebo group, and no significant change in MCA-PI was observed in any group. Maternal arterial blood pressure decreased significantly with administration of both sildenafil citrate and nitroglycerine. Conclusion Sildenafil citrate has an effect similar to nitroglycerine in improving Doppler indices and blood flow of uterine and umbilical arteries in growth-restricted fetuses.