Objectives: The success of ovulation induction-intrauterine insemination (OI-IUI) procedures may be limited by the absence of ovulation detection. The aim of this study was to evaluate the empirical use of ultrasonography and luteal phase progesterone (P4) as ovulation indicators and determine its effect on pregnancy outcome in OI-IUI cycles.
Material and methods: This prospective observational study, which was performed in a university setting, included 107 women with unexplained infertility. Following OI, IUI was performed 36 hours after human chorionic gonadotropin (hCG). P4 was measured 72–96 hours after hCG. At the same time, the appearance of ovaries and signs indicative of ovulation, which are decreased follicle dimensions, irregularity of follicular walls, and the presence of free fluid in the Douglas pouch, were noted.
Results: In 58 patients (54.2%), ovulation was detected at the P4 level of > 10 ng/mL. Eighty-nine patients had ultrasound images suggestive of ovulation. However, only 50 of these were confirmed ovulation as indicated using P4. Implantation was observed in a total of 13 patients (12.1%). All patients were in the ovulation detected group with P4 > 10 ng/mL (AUC: 0.750; p = 0.004). P4 of > 21.5 ng/mL detected successful ovulation and was strongly associated with implantation with 77% sensitivity and 61% specificity (OR: 9.9; 95% CI: 2.4–41.2). Body mass index (BMI) > 23.9 kg/m2 was a reliable anovulation indicator as a secondary outcome (AUC: 0.696; p = 0.02).
Conclusions: In 45.8% of the patients, ovulation did not occur even with OI treatment. The association of progesterone measurement and ovarian ultrasound scanning between 72 and 96 hours after hCG treatment can be used to detect ovulation. In doing so, we can find the optimal treatment for patients with infertility in their next cycle.