Predictive Factors for Pregnancy after Intrauterine Insemination: A Prospective Study

Abstract

Introduction: Intrauterine insemination (IUI) is a widely used first-line treatment for selected cases of subfertil- ity due to its simplicity, cost-effectiveness, and minimal invasiveness. However, its success is influenced by multiple factors related to the couple, ovarian stimulation protocol, and semen parameters. Identifying predictive factors for pregnancy following IUI can help in optimizing patient selection and improving outcomes. Objectives: To evaluate the clinical, hormonal, and procedural factors associated with successful pregnancy following IUI and to identify significant predictors that influence the likelihood of conception. Materials and Methods: This prospective interventional open-label study was conducted in the Department of Obstetrics and Gynecology, Eden Hospital, Medical College and Hospital, Kolkata, over one year. Protocol de- velopment began in November 2016, and patient recruitment and data collection took place from January to July 2017 after ethics committee approval, followed by data analysis and thesis preparation. Women seeking infer- tility treatment in the OPD were counselled and enrolled after meeting the inclusion and exclusion criteria. Based on a previous study [xiv] and the formula n = 4pq/l², the calculated sample size was 257; however, due to time constraints and single-researcher limitations, 50% of this number (≈130 IUI cycle) were included. Results: In our study, female age, male age, BMI, and type of infertility were not significantly associated with pregnancy outcomes, although no women were older than 35 years and most pregnancies occurred in men over 35 years, contrasting with Mathieu et al., who reported poorer outcomes with increasing male age [93]. The ma- jority of pregnancies (75%) occurred in women with infertility duration less than six years, with the highest conception rates seen in unexplained infertility (75%) followed by endometriosis (25%). Laparoscopic tubal patency assessment were more common in the conception group. Hormonal analysis showed that all who con- ceived had LH and FSH ≤10 mIU/mL, significantly lower prolactin (p = 0.0298), and no significant differences in TSH. Fasting and postprandial blood sugar levels were higher in the conception group but within normal lim- its. All pregnancies occurred when two preovulatory follicles were present, while endometrial thickness had no significant effect. Semen analysis revealed significantly higher semen volume, pre-wash sperm count, motility, and post-wash count among those who conceived. Conclusion: Several factors including cause of infertility, infertility duration, FSH, LH and PROLACTIN level, follicular response, semen volume, prewash sperm count, motility and post-wash sperm count are predictive of IUI success. Careful selection of patients and individualized stimulation protocols based on these predictors can enhance pregnancy outcomes in IUI cycles.