Effects of Preconceptional Vitamin D Levels on IVF Outcomes in Infertile Patients with Polycystic Ovary Syndrome: A Retrospective Cohort Study

Abstract Background: Vitamin D is known to have various roles in different stages of reproduction, and abnormalities in its levels are observed in many diseases, including polycystic ovary syndrome (PCOS). This study aimed to determine the relationship between the outcomes of the in vitro fertilization (IVF) procedures with respect to the initial vitamin D levels among patients diagnosed with PCOS. Methods: This study was designed as a retrospective cohort study of 1174 PCOS patients who consulted Acıbadem Maslak Hospital IVF Clinic between January 2015 and September 2022. The effect of preconceptional vitamin D levels on IVF outcomes of PCOS patients was investigated. Data analysis explored initial vitamin D levels’ correlation with IVF outcomes with SigmaPlot 14.5. Results: We observed a correlation between the patient's preconceptional vitamin D status and positive clinical pregnancy rates (p= <0.001) as well as increased endometrial thickness on hCG day (p=<0.001). The cut-off value of vitamin D level for a positive hCG test was calculated as 13.24 ng/mL. No association was seen in the other IVF outcome parameters, miscarriage rates, and the subgroup analysis of clinical pregnancy rates according to endometrial thickness. Conclusions: Observing increased positive hCG tests generated promising findings, as it indicates that the PCOS patients’ initial vitamin D status can influence supplementation efforts as their final pregnancy results were significantly impacted. Conclusively, it may be said that patients having vitamin D values above 13.24 ng/mL are more likely to get a positive hCG result after IVF procedures.