Maternal vitamin B-12 and folate status during pregnancy and excessive infant crying

Background: The etiology of excessive infant crying is largely unknown. We hypothesize that excessive infant crying may have an early nutritional origin during fetal development. Aims: This study is the first to explore whether (1) maternal vitamin B-12 and folate status during pregnancy are associated with excessive infant crying, and (2) whether and how maternal psychological well-being during pregnancy affects these associations. Study design: Women were approached around the 12th pregnancy week to complete a questionnaire (n = 8266) and to donate a blood sample (n = 4389); vitamin B-12 and folate concentrations were determined in serum. Infant crying behavior was measured through a postpartum questionnaire (+/- 3 months; n = 5218). Subjects: Pregnant women living in Amsterdam and their newborn child. Outcome measures: Excessive infant crying, defined as crying >= 3 h/day on average in the past week. Results: Multiple logistic regression analysis was performed for 2921 (vitamin B-12) and 2622 (folate) women. Vitamin B-12 concentration (categorized into quintiles) was associated with excessive infant crying after adjustment for maternal age, parity, ethnicity, education, maternal smoking and psychological problems (OR [95%CI]: Q1 = 3.31[1.48-7.41]: Q2 = 2.50[1.08-5.77]; Q3 = 2.59[1.12-6.00]; Q4 = 2.77[1.20-6.40]; Q5 = reference). Stratified analysis suggested a stronger association among women with high levels of psychological problems during pregnancy. Folate concentration was not associated with excessive infant crying. Conclusions: First evidence is provided for an early nutritional origin in excessive infant crying. A low maternal vitamin B-12 status during pregnancy could, in theory, affect infant crying behavior through two potential mechanisms: the methionine-homocysteine metabolism and/or the maturation of the sleep-wake rhythm. (C) 2011 Elsevier Ireland Ltd. All rights reserved.