Euploid embryo counts in IVF: Associations with maternal age, vitamin D, sleep quality, and BMI.

Maternal age is a known correlate of embryo euploidy, but the associations with vitamin D status, sleep quality, and body mass index (BMI) are not fully understood. This study investigated these factors in relation to euploid embryo counts per in vitro fertilization (IVF) cycle. This retrospective cross-sectional study included 42 women undergoing a single IVF cycle with preimplantation genetic testing for aneuploidy at one center. Serum vitamin D levels, BMI, and Pittsburgh Sleep Quality Index (PSQI) scores were recorded before ovarian stimulation. Analyses involved multivariable linear regression, bootstrapping with 1,000 resamples, sensitivity analysis, and binomial models that accounted for the number of embryos tested. Linear regression revealed negative associations between maternal age and PSQI scores with euploid embryo counts, while vitamin D was positively associated (regression coefficient = 0.055; p = 0.006). BMI was not a significant factor. Vitamin D was the only factor whose bias-corrected and accelerated bootstrap 95% confidence interval excluded zero (0.006-0.145), and its association remained significant in sensitivity analysis. Higher vitamin D levels were also linked to a higher euploidy rate in binomial models (p = 0.017), including models adjusted separately for anti-Müllerian hormone (p = 0.026) or antral follicle count (p = 0.044). Maternal age, BMI, and PSQI scores were not significant in these models. Across all analyses, vitamin D demonstrated the most consistent association with embryo euploidy. These preliminary findings from a small observational cohort warrant confirmation in larger prospective studies and do not establish causality.