Elevated maternal serum folate in the third trimester and reduced fetal growth: a longitudinal study.
ABSTRACT This study aimed to examine the association of fetal growth and elevated third trimester maternal serum folate due to folic acid (FA) supplement intake. Dietary intake, use of FA supplements, weight, and blood biomarkers of B-vitamins (serum folate, pyridoxal, vitamin B(12), and plasma total homocysteine) were observed in 33 healthy pregnant women at the third trimester (average gestational age 35 wk). Birth outcomes were assessed through hospital birth records. Infant anthropometry and maternal blood biomarkers were followed up at 1 mo postpartum. Fourteen women were taking FA supplements at the third trimester. Dietary intake was similar among FA users and non-users, but serum folate and pyridoxal were significantly higher in users (11.6±6.7 vs. 6.1±3.2 ng/mL, and 13.8±21.7 vs. 3.2±1.4 ng/mL, respectively). Plasma total homocystein (tHcy) was higher in non-users compared to users, but not significantly. Nine FA users and eight non-users had low serum vitamin B(12) values (<203 pg/mL). Nine FA users and all non-users had low serum pyridoxal values (<7.0 ng/mL). Infant birthweight was significantly lower in users compared to non-users (2,894±318 vs. 3,154±230 g). At 1 mo postpartum, infant weight and length were similar between FA users and non-users, but infant weight gain was larger in users. Higher serum folate values due to FA use in the third trimester was related to reduced fetal size. Excess FA under low vitamin B(6) and B(12) status may affect fetal growth.
Article: Validity and reproducibility of folate and vitamin B(12) intakes estimated from a self-administered diet history questionnaire in Japanese pregnant women.[show abstract] [hide abstract]
ABSTRACT: No validated dietary questionnaire for assessing folate and vitamin B(12) intakes during pregnancy is available in Japan. We evaluated the validity and reproducibility of intakes of folate and vitamin B(12) estimated from a self-administered diet history questionnaire (DHQ) in Japanese pregnant women. A sample of 167 healthy subjects with singleton pregnancies in the second trimester was recruited at a private obstetric hospital in metropolitan Tokyo from June to October 2008 (n = 76), and at a university hospital in Tokyo from June 2010 to June 2011 (n = 91). The dietary intakes of folate and vitamin B(12) were assessed using the DHQ. The serum concentrations of folate and vitamin B(12) were measured as reference values in the validation study. To assess the reproducibility of the results, 58 pregnant women completed the DHQ twice within 4-5 week interval. Significantly positive correlations were found between energy-adjusted intakes and serum concentrations of folate and vitamin B(12) (r = 0.286, p < 0.001 and r = 0.222, p = 0.004, respectively). After excluding the participants with nausea (n = 121), the correlation coefficient for vitamin B(12) increased to 0.313 (p = 0.001). When participants were classified into quintiles based on intakes and serum concentrations of folate and vitamin B(12), approximately 60% were classified in the same or adjacent quintile. The intraclass correlation coefficients of the two-time DHQ were 0.725 for folate and 0.512 for vitamin B(12). The present study indicated that the DHQ had acceptable validity and reproducibility for assessing folate and vitamin B(12) intakes in Japanese pregnant women.Nutrition Journal 03/2012; 11:15. · 2.48 Impact Factor