Maternal caffeine intake in pregnancy is inversely related to childhood peer problems in Japan: The Kyushu Okinawa Maternal and Child Health Study

Objectives: The present prebirth cohort study examined the association between maternal caffeine consumption during pregnancy and behavioral problems in Japanese children aged 5 years. Methods: Subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, and peer problems were assessed using the Japanese parent-report version of the Strengths and Difficulties Questionnaire. Adjustment was made for maternal age, gestation at baseline, region of residence at baseline, number of children at baseline, maternal and paternal education, household income, maternal depressive symptoms during pregnancy, maternal alcohol intake during pregnancy, maternal smoking during pregnancy, child's birth weight, child's sex, breastfeeding duration, and smoking in the household during the first year of life. Results: The contributors of caffeine in the diet during pregnancy were Japanese and Chinese tea (74.8%), coffee (13.0%), black tea (4.4%), confectionaries (4.0%), and soft drinks (3.7%). Higher maternal caffeine consumption during pregnancy was independently associated with a reduced risk of peer problems in the children: the adjusted odds ratios (95% confidence intervals) in the first, second, third, and fourth quartiles of maternal caffeine consumption during pregnancy were 1 (reference), 0.61 (0.35-1.06), 0.52 (0.29-0.91), and 0.51 (0.28-0.91), respectively (P for trend = 0.01). Maternal caffeine intake during pregnancy was not evidently related to the risk of emotional problems, conduct problems, or hyperactivity problems in the children. Conclusions: Maternal caffeine consumption, mainly from Japanese and Chinese tea, during pregnancy may be preventive against peer problems in Japanese children.