The link between arsenic exposure and deficits in children's neurodevelopment has been suggested, but it remains unclear regarding the arsenic-related effects on the developing brain in early life. To investigate the associations of in utero arsenic exposure with neonatal neurobehavioral development, we conducted a cross-sectional study of 892 mother-infant pairs from 10 hospitals of different levels in Shanghai, China. The concentrations of arsenic were determined in cord blood samples. Neurobehavioral measures were administered at 3 days postpartum in full-term newborns using the neonatal behavioral neurological assessment (NBNA). Logistic regression models were used to estimate odds ratios for dichotomous NBNA outcomes. After adjusting for potential confounders, a natural log unit (ln-unit) increase in cord blood arsenic was associated with 90% increased odds of low NBNA score (95% confidence interval [CI]: 1.62, 2.23). As for clusters, each ln-unit arsenic increase was associated with 47% increased odds of low score for behavior (95% CI: 1.31, 1.66) and 36% increased odds of low score for passive muscle tone (95% CI: 1.23, 1.51). Odds ratios comparing extreme tertiles were 8.62 (95% CI: 4.19, 17.8) for total scale, 3.69 (95% CI: 2.35, 5.82) for behavior, and 3.32 (95% CI: 2.21, 4.97) for passive tone (all p-trend < 0.001). Stratified analyses showed that these associations were strengthened in newborns of mothers over 29 years of age. Our results provide evidence for an inverse association between low-level prenatal arsenic exposure and neurobehavioral performance of newborns, particularly among those born to older mothers. Further studies are warranted to confirm these findings and to determine whether such decrements in early neurodevelopment persist in later childhood.

With the increasing recognition of the importance of the non-skeletal effects of vitamin D (VitD), more and more attention has been drawn to VitD status in early life. However, the VitD status of newborns and factors that influence VitD levels in Shanghai, China, remain unclear. A total of 1030 pregnant women were selected from two hospitals in Shanghai, one of the largest cities in China located at 31 degrees north latitude. Umbilical cord serum concentrations of 25-hydroxy vitamin D [25(OH)D] were measured by LC-MS-MS, and questionnaires were used to collect information. The median cord serum 25(OH)D concentration was 22.4 ng/mL; the concentration lower than 20 ng/mL accounted for 36.3% of the participants, and the concentration lower than 30 ng/mL for 84.1%. A multivariable logistic regression model showed that the determinants of low 25(OH)D status were being born during autumn or winter months and a lack of VitD-related multivitamin supplementation. The relative risk was 1.7 for both autumn (95% CI, 1.1–2.6) and winter (95% CI, 1.1–2.5) births (p < 0.05). VitD-related multivitamin supplementation more than once a day during pregnancy reduced the risk of VitD deficiency [adjusted OR (aOR) = 0.6, 95% CI (0.45–1.0) for VitD supplementation] (p < 0.05). VitD deficiency and insufficiency are common in newborns in Shanghai, China, and are independently associated with season and VitD supplementation. Our findings may assist future efforts to correct low levels of 25(OH)D in Shanghai mothers and their newborn children.