Iron intake and iron status during pregnancy and risk of congenital heart defects: A case-control study.

BACKGROUND: The relationships between iron nutritional status and congenital heart defects (CHDs) among humans are still unclear. This study aimed to explore the associations of maternal iron intake during pregnancy and maternal and neonatal iron status with CHDs. METHODS: This hospital-based case-control study analyzed 474 cases and 948 controls in Shaanxi China. Eligible women waiting for delivery in the hospital were interviewed to report their diets and characteristics during pregnancy. We conveniently collected maternal blood before delivery and neonatal cord blood to get a subgroup of 50 cases and 100 controls. Mixed logistic regression models were used to estimate ORs (95%CIs) for CHDs associated with iron intake. Mixed linear regression models were used to assess the relationships between CHDs and iron status. RESULTS: Mothers whose fetuses have CHDs were less likely to have higher intakes of total iron and heme iron during pregnancy, and the tests for linear trend were significant (all P < 0.05). Mothers whose fetuses have CHDs were less likely to take iron supplements during pregnancy (OR = 0.28, 95%CI: 0.21, 0.36) and during the first trimester (OR = 0.32, 95%CI: 0.12, 0.84). Maternal SF and Hb concentrations before delivery were lower and maternal sTfR/SF before delivery was higher among the cases than the controls. CONCLUSIONS: Mothers whose fetuses have CHDs are less likely to have higher intakes of total iron and heme iron and take iron supplements during pregnancy compared to their counterparts. Maternal iron status before delivery is low among mothers whose fetuses have CHDs.

The association of maternal dietary folate intake and folic acid supplementation with small-for-gestational-age births: a cross-sectional study in Northwest China.

The effect of maternal folate intake on small-for-gestational-age (SGA) births remains inconclusive. The present study aimed to investigate the associations of maternal folate intake from diet and supplements with the risk of SGA births using data from a cross-sectional study in Shaanxi Province of Northwest China. A total of 7307 women who were within 12 months (median 3; 10th-90th percentile 0-7) after delivery were included. Two-level models were adopted to examine the associations of folate (dietary folate, supplemental folic acid and total folate) intake with the risk of SGA births and birth weight Z score, controlling for a minimum set of confounders that were identified in a directed acyclic graph. Results showed that a higher supplemental folic acid intake during the first trimester was negatively associated with the risk of SGA births (≤60 d v. non-use: OR 0·80; 95 % CI 0·66, 0·96; >60 d v. non-use: OR 0·78; 95 % CI 0·65, 0·94; Ptrend = 0·010; per 10-d increase: OR 0·97; 95 % CI 0·95, 0·99). A higher total folate intake during pregnancy was associated with a reduced risk of SGA births (highest tertile v. lowest tertile: OR 0·77; 95 % CI 0·64, 0·94; Ptrend = 0·010; per one-unit increase in the log-transformed value: OR 0·81; 95 % CI 0·69, 0·95). A similar pattern was observed for the birth weight Z score. Our study suggested that folic acid supplementation during the first trimester and a higher total folate intake during pregnancy were associated with a reduced risk of SGA births.