The relationship between serum vitamin D levels and pregnancy in patients undergoing intrauterine insemination

Abstract

Purpose: Intrauterine insemination is the first-line treatment option in unexplained infertility. This study aims to determine the relationship between pregnancy outcome of intrauterine insemination cycles with serum vitamin D levels. Materials and methods: Data from 212 ovulation induction cycles of 135 patients undergoing IUI after ovulation induction with gonadotropins were analyzed. Serum FSH, LH, estradiol, prolactin, anti-müllerian hormone (AMH), TSH, and vitamin 25(OH) D levels, ovarian response, and pregnancy results were analyzed. Patients were evaluated as Group A (20 ng/mL) and Group B (<20 ng/mL) according to serum vitamin D level. Results:The mean age of the patients was 29.71±4.18. The mean duration of infertility was 4.31±2.55 years. A total of 212 cycles were included in the study. The mean gonadotropin dose used per cycle was 832.0±463.8 IU, the mean induction time was 11.49±3.45 days. No statistically significant difference was detected between Group A (vitamin D ≥20 ng/mL) and Group B (vitamin D <20 ng/mL) regarding age, duration of infertility, BMI, AMH, antral follicle count, induction time, total gonadotropin dose, endometrial thickness (p<0.05). The pregnancy rate in Group A was 18.3% (n = 11), and 16.4% (n = 25) in Group B (p=0.742). No correlation was found between vitamin D and BMI, duration of infertility, antral follicle number, AMH, induction time, and the number of follicles. ROC curve analysis showed that vitamin D levels are not predictive for pregnancy (AUC=0.478 p=0.684). Conclusion: Serum vitamin D levels do not affect the pregnancy rates after IUI cycles following the ovulation induction.