The Effect of Endometrial Thickness on The Day of Human Chorionic Gonadotropin Injection on Reproductive Outcome in Clomiphene Citrate and Intrauterine Insemination Cycles

Backround: To evaluate the effect of endometrial thickness (EMT) on the day of Human Chorionic Gonadtropin(hCG) injection on reproductive outcome in clomiphene citrate and intrauterine insemination cycles (CC + IUI). Methods Overall 640 cycles in couples with unexplained infertility or WHO Category 2 normogonadotropic anovulatory women and met the inclusion criteria were analyzed retrospectively. Our study was approved by Ministry of Health, Health Sciences University Etlik Zübeyde Hanim Women’s Institutional Board (30/12/2020-90057706-799) who applied to Reproductive Endocrinology Department of a tertiary center between February 2019 and February 2020 and received ovulation induction with CC + IUI. The demographic characteristics and EMT at the hCG injection day were compared in the group with a clinical pregnancy with those who failed to achieve pregnancy. Results Out of the evaluated 640 cycles, 92 cases had a high β-hCG (14.4%) and 80 (12.5%) resulted in a clinical pregnancy. While 23 (23/640, 3.6%) of the cases with clinical pregnancy experienced spontaneous abortion, 52 (8.1%) resulted in live birth. Maternal age, duration of infertility and clomiphene citrate dosage were found to have an impact on the clinical pregnancy and live birth ratio. The cut-off value for endometrial thickness is 8.45 mm (sensitivity 49.4%, specificity 55.3%) for clinical pregnancy. The incidence of biochemical pregnancy was less while the incidence of clinical pregnancy (p = 0.010) and live birth (p = 0.002) was high in cases with an EMT > 8–9 mm on the day of β-HCG injection Conclusion Higher pregnancy rates have been reported at certain EMT values. However, cycle success can be predicted not only by EMT but also by considering other factors such as female age, infertility duration, and endometrial pattern.