Does Luteal Phase Support Effect Pregnancy Rates in Intrauterine Insemination Cycles? A Prospective Randomised Controlled Study in a Tertiary Center

Intrauterine insemination (IUI) is a common treatment for couples with subfertility. Clomiphene citrate, gonadotropins, and letrozole are used for ovulation induction in IUI cycles. It has been well documented that luteal support with exogenous progesterone after in vitro fertilization is associated with higher pregnancy and live birth rates. Yet, luteal phase support in IUI cycles has become a debatable issue. The aim of this prospective controlled study was to assess the effect of luteal phase vaginal progesterone supplementation on β-hCG positivity and clinical pregnancy rates in women undergoing IUI. This prospective controlled randomised study was conducted at a tertiary infertility center. 87 patients with unexplained infertility or male subfertility who were treated with IUI using gonadotropins were enrolled. Patients in the study group (n = 44) received luteal phase vaginal progesterone supplementation. Patients in the control group (n = 43) did not receive any luteal phase support. There was no statistical difference between two groups in terms of β-hCG positivity and clinical pregnancy rates. Our findings do not show any beneficial effect of luteal phase support in IUI cycles stimulated with gonadotropins. Although luteal phase support in IUI cycles stimulated with gonadotropins is widely adopted, there is a lack of robust evidence.