Maternal Serum 25-Hydroxyvitamin D and Measures of Newborn and Placental Weight in a U.S. Multicenter Cohort Study

• Published in: The journal of clinical endocrinology and metabolism 2013-01, Vol.98 (1), p.398-404
• Main Authors: Gernand, Alison D, Simhan, Hyagriv N, Klebanoff, Mark A, Bodnar, Lisa M
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Birth Weight - physiology; Cohort Studies; Endocrine Research; Endocrinopathies; Feeding. Feeding behavior; Female; Fetal Development - physiology; Fundamental and applied biological sciences. Psychology; Head - anatomy & histology; Head - growth & development; Humans; Infant, Newborn - physiology; Male; Medical sciences; Mothers; Organ Size - physiology; Placenta - anatomy & histology; Pregnancy - blood; United States; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Vitamin D - analogs & derivatives; Vitamin D - blood; Young Adult
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2012-3275

Context: Inconsistent associations between maternal vitamin D status and fetal size have been published in small studies. Objective: Our objective was to examine the association between maternal 25-hydroxyvitamin D [25(OH)D] levels and measures of newborn and placental weight. Design and Setting: We measured maternal 25(OH)D in mothers from the Collaborative Perinatal Project, an observational cohort conducted in 12 U.S. medical centers from 1959 to 1965. Participants: Women delivering singleton, term, live births with 25(OH)D measured at a gestation of 26 wk or less (n = 2146). Main Outcome Measures: Birth weight, ponderal index, placental weight, the placental to fetal weight ratio, and small for gestational age were measured. Hypotheses were formulated after data collection. Results: After confounder adjustment, mothers with 25(OH)D of 37.5 nmol/liter or greater gave birth to newborns with 46 g [95% confidence interval (CI), 9–82 g] higher birth weights and 0.13 cm (0.01–0.25 cm) larger head circumferences compared with mothers with less than 37.5 nmol/liter. Birth weight and head circumference rose with increasing 25(OH)D up to 37.5 nmol/liter and then leveled off (P < 0.05). No association was observed between 25(OH)D and ponderal index, placental weight, or the placental to fetal weight ratio. Maternal 25(OH)D of 37.5 nmol/liter or greater vs. less than 37.5 nmol/liter in the first trimester was associated with half the risk of small for gestational age (adjusted odds ratio 0.5; 95% CI 0.3–0.9), but no second-trimester association was observed. Conclusions: Maternal vitamin D status is independently associated with markers of physiological and pathological growth in term infants. Adequately powered randomized controlled trials are needed to test whether maternal vitamin D supplementation may improve fetal growth.