Maternal serum vitamin D at 11-13 weeks in pregnancies delivering small for gestational age neonates.

OBJECTIVES To determine if maternal serum levels of 25(OH)D at 11-13 weeks' gestation are altered in pregnancies that subsequently deliver small for gestational age (SGA) neonates and whether the levels are related to placental function reflected in serum concentration of pregnancy-associated plasma protein-A (PAPP-A). METHODS Serum 25(OH)D and PAPP-A were measured at 11-13 weeks in 150 singleton pregnancies that delivered SGA neonates and 1,000 appropriate for gestational age (AGA) controls. The median 25(OH)D and PAPP-A multiple of the unaffected median (MoM) in the outcome groups were compared. RESULTS In the SGA, the median serum 25(OH)D and PAPP-A were significantly decreased (0.78 vs. 1.00 MoM, p < 0.0001 and 0.78 vs. 1.00 MoM, p < 0.0001, respectively). The incidence of 25(OH)D levels below the 10th percentile was significantly higher in the SGA than the AGA group in Caucasian women (p = 0.002) but not in those of African racial origin (p = 0.183). There was no significant association between 25(OH)D MoM and PAPPA MoM in either the SGA or the AGA groups. CONCLUSION Serum 25(OH)D levels at 11-13 weeks are decreased in pregnancies of Caucasian women that deliver SGA neonates but not in those of African racial origin. The decrease in 25(OH)D levels is unrelated to placental function.