Relationship between serum vitamin D levels and pregnancy rate of women with recurrent implantation failure undergoing IVF

Objective: Vitamin D deficiency has been shown to be associated with pregnancy complications due to the effect on implantation. However, the effect of vitamin D on the clinical outcomes of IVF in women with recurrent implantation failure is unclear. Present study aimed to investigate the effect of vitamin D status in recurrent implantation failure (RIF) patients undergoing in vitro fertilization (IVF) cycles.

Methods: A cross-sectional study was carried out on 52 women with RIF undergoing IVF treatments from 2018 to 2019. Blood samples were collected from participant after 2 weeks of embryo transfer and then serum 25-OH vitamin D levels were measured using enzyme-linked immunosorbent assay (ELISA) method. Clinical pregnancy and patients’ characteristics were evaluated.

Results: The incidence of vitamin D deficiency, insufficiency and sufficiency among the studied population were 7.7%, 73.1% and 19.2%, respectively. Vitamin D levels were significantly associated with clinical pregnancy in patients with ≥30 years old, being overweight, duration of marriage and infertility duration ≥5 years and having history of abortion. By adjusting confounding factors in the multivariate analysis, we found a significant association between vitamin D levels and clinical pregnancy in RIF patients (p=0.007).

Conclusion: There is a significant correlation between vitamin D levels and clinical pregnancy rate in RIF woman undergoing IVF. However, more randomized, controlled trials are suggested.