Third Trimester Vitamin D Status Is Associated With Birth Outcomes and Linear Growth of HIV-Exposed Uninfected Infants in the United States.

BACKGROUND

Vitamin D status in pregnancy may influence the risk of prematurity, birth size, and child postnatal growth, but few studies have examined the relationship among pregnant women living with HIV.

METHODS

We conducted a prospective cohort study of 257 HIV-infected mothers and their HIV-exposed uninfected infants who were enrolled in the 2009-2011 nutrition substudy of the Surveillance Monitoring for ART Toxicities (SMARTT) study. HIV-infected pregnant women had serum 25-hydroxyvitamin D (25(OH)D) assessed in the third trimester of pregnancy, and their infants' growth and neurodevelopment were evaluated at birth and approximately 1 year of age.

RESULTS

The mean third trimester serum 25(OH)D concentration was 35.4 ± 14.2 ng/mL with 15% of women classified as vitamin D deficient (<20 ng/mL) and 21% as insufficient (20-30 ng/mL). In multivariable models, third trimester vitamin D deficiency and insufficiency were associated with -273 g [95% confidence interval (CI): -450 to -97] and -203 g (95% CI: -370 to -35) lower birth weights compared with vitamin D sufficient women, respectively. Maternal vitamin D deficiency was also associated with shorter gestation (mean difference -0.65 weeks; 95% CI: -1.22 to -0.08) and lower infant length-for-age z-scores at 1 year of age (mean difference: -0.65; 95% CI: -1.18 to -0.13). We found no association of vitamin D status with infant neurodevelopment at 1 year of age.

CONCLUSION

Third trimester maternal vitamin D deficiency was associated with lower birth weight, shorter length of gestation, and reduced infant linear growth. Studies and trials of vitamin D supplementation in pregnancy for women living with HIV are warranted.