PROSPECTIVE STUDY OF THE RELATIONSHIP BETWEEN MATERNAL SERUM 25-HYDROXY VITAMIN D LEVELS DURING THE ANTENATAL PERIOD AND OVARIAN RESERVE IN FEMALE NEWBORNS

Abstract

Objective

To determine the relationship between maternal serum 25-hydroxy vitamin D [25(OH)D] levels during the antenatal period and ovarian reserve in female newborns, and to investigate the connection between these parameters.

Materials and Methods

This prospective cohort study at Bursa Yuksek Ihtisas Hospital (July 2023-April 2024) included 200 pregnant women, with 95 completing the study by delivering at 37 weeks or later without complications. 25(OH)D and anti-mullerian hormone (AMH) levels were measured in maternal blood between 12-24 weeks of gestation, before delivery, and in neonatal cord blood. Participants were divided into three groups based on second-trimester 25(OH)D levels: <10 ng/ml (Group 1), 10-20 ng/ml (Group 2), and ≥20 ng/ml (Group 3). Comparisons were made for demographic data, maternal 25(OH)D and AMH levels, and cord blood AMH and 25(OH)D levels. Spearman correlation analysis was used to analyze relationships between parameters.Logistic regression analyzed factors affecting cord blood AMH.

Results

Of the 95 patients, 36 were in Group 1, 43 in Group 2, and 16 in Group 3. The groups were similar in terms of age, BMI, gestational week, antenatal vitamin D supplementation, birth weight, and Apgar scores. There was no statistically significant difference between the groups in terms of pre-delivery maternal AMH and neonatal cord blood AMH levels. There was no correlation between maternal second trimester 25(OH)D levels and pre-delivery maternal AMH and cord blood AMH levels. However, maternal second trimester 25(OH)D levels were significantly positively correlated with neonatal cord blood 25(OH)D levels and maternal pre-delivery 25(OH)D levels. Additionally, neonatal cord blood 25(OH)D levels were significantly positively correlated with cord blood AMH levels (r=0.215, p=0.037). Factors affecting neonatal cord blood AMH levels were evaluated using linear regression analysis. According to the regression model, which included age, birth weight, and neonatal cord blood 25(OH)D as independent variables, the regression model was significant, and cord blood 25(OH)D was found to have a significant impact on neonatal AMH levels (R² = 0.097, p=0.025).

Conclusion

Vitamin D levels impact the female reproductive system, with maternal vitamin D levels correlating with those in newborns. This suggests maternal vitamin D may affect gonadal development in female fetuses. Neonatal AMH measurement, an ovarian folliculogenesis marker, can help identify these effects. Umbilical cord AMH levels in female fetuses might be influenced by neonatal vitamin D levels. Therefore, adequate maternal vitamin D supplementation during pregnancy is crucial for healthy gonadal development in female newborns. Larger, well-designed randomized studies are needed for more definitive conclusions.