Influence of vitamin D levels on fertilization rate and pregnancy after in vitro fertilization: a retrospective analysis

Currently, vitamin D deficiency is associated with an increased risk of abnormal pregnancy implantation, leading to obstetric complications such as preeclampsia and fetal growth restriction. However, the effect of vitamin D on infertility treatment outcomes in couples using assisted reproductive technologies (ART) remains poorly studied. Aim - to determine whether vitamin D is associated with clinical outcomes of in vitro fertilization (IVF), specifically to examine the relationship between preconception serum vitamin D level and pregnancy outcomes following ART in women with infertility. Materials and methods. The study was conducted from September 2023 to September 2024. A total of 100 patients selected for the study had their vitamin D level measured before undergoing ART. All participants were divided into three groups based on their total vitamin D levels: the Group 1 - 65 patients with vitamin D level deficiency (<50 nmol/L); the Group 2 - 24 patients with insufficient vitamin D level (50-75 nmol/L); the Group 3 - 11 patients with optimal vitamin D level (>75 nmol/L). Multivariate logistic regression was used to assess the predictors of ongoing pregnancy. Results. The rates of ongoing pregnancy were as follows 53.8% (35/65) in the Group 1, 66.6% (16/24) in the Group 2, and 72.7% (8/11) in the Group 3. Women with optimal vitamin D level are more likely to conceive and achieve an ongoing pregnancy through IVF compared to those with vitamin D deficiency or insufficiency. Conclusions. Vitamin D deficiency and insufficiency are common among women undergoing infertility treatment with ART. The approximate rate of ongoing pregnancy achieved in women receiving ART is associated with serum vitamin D levels and is higher in those with optimal vitamin D status. The study was conducted in accordance with principles of the Declaration of Helsinki. Research protocol was approved by local ethics committee of the participating institution. Informed consent was obtained. The author declares no conflict of interest.