Effect of Nitric Oxide Donors on Uterine and Subendometrial Blood Flow in Patients with Unexplained Infertility: A Randomized Controlled Trial

Abstract

Unexplained infertility has been defined, by the Practice Committee of the American Society of Reproductive Medicine (ASRM), as inability of a couple to conceive for at least 12 months, with unremarkable standard infertility evaluation ((ASRM), 2006). Although estimates vary, the prevalence of unexplained infertility is approximately 15–30% Aim of the Work to evaluate the effect of nitroglycerine transdermal patches on uterine and subendometrial blood flow in women with unexplained infertility. Patients and Methods Transdermal nitroglycerine patch was administered to the allocated group from the 2nd day of cycle till maturation of the follicles ≥ 18 mm just for one cycle. Results The relatively underdeveloped endometrial thickness did not change significantly after treatment of women with unexplained infertility with nitroglycerin and remained significantly lower than women of the fertile group. Also, nitroglycerin treatment did not result in significant change in uterine artery Doppler indices. However, uterine artery indices of nitroglycerin-treated women did not also show a significant difference (P > 0.05) from fertile women. On the contrary, nitroglycerin treatment in women with unexplained infertility significantly increased subendometrial 3D power Doppler indices to mean values that did not differ significantly from the fertile women. According to the results of the current study, biochemical pregnancy was more commonly achieved in the nitroglycerin group compared to the control group (6.67% vs 3.33%), Yet this difference failed to prove statistical significance. Although adverse effects of nitroglycerin treatment in the current study, namely headache, blurring of vision and hypotension, were more common on the nitroglycerin group compared to the control and fertile groups; this difference couldn’t reach statistical significance (P > 0.05). Conclusion Doppler study of uterine hemodynamics can be considered in infertility work-up. Although still lacking evidence, women with suboptimal uterine perfusion may be offered therapies improving uterine blood flow, such as nitroglycerin.