MATERNAL VITAMIN D STATUS IN RELATION TO FETAL GROWTH AND SURVIVAL: A PROSPECTIVE COHORT STUDY

Background and objectives: Fetal growth depends on placenta function. Maternal vitamin D status has been inversely associated with uteroplacental dysfunction. We aimed to investigate the associations between vitamin D status in early and late pregnancy with prevalence of neonatal small for gestational age (SGA), low birth weight (LBW), preterm delivery and pregnancy loss. Methods: Pregnant women were recruited at antenatal clinics in Sweden (latitude 57-58°N). Serum 25-hydroxyvitamin D (25OHD) was analyzed in gestational week ≤16 (trimester 1 (T1), N=2046) and >31 (trimester 3 (T3), N=1816) by liquid chromatography tandem mass spectrometry. Gestational and neonatal data were retrieved from medical records. Results: Logistic regression showed that 25OHD at T1 was only associated with pregnancy loss (OR 0.99, p=0.041). 25OHD at T3 ≥100 nmol/L was associated with lower odds of SGA (OR 0.3, p= 0.031) and LBW (OR 0.2, p= 0.046), compared to vitamin D deficiency (25OHD