Relation of caffeine intake during pregnancy to intrauterine growth retardation and preterm birth.

Whether caffeine intake during pregnancy is related to intrauterine growth retardation, low birth weight, and preterm birth remains unclear. The purpose of this population-based study is to assess these associations and to evaluate the interaction between caffeine intake and smoking. The study participants (n = 7,025) were women who lived in Quebec City, Canada, and the surrounding area who gave birth between January 1989 and October 1989 to a singleton liveborn neonate. Information on gestational age at delivery, caffeine intake (coffee, tea, chocolate, and colas) during pregnancy, and several potential confounders was obtained by telephone a few weeks after delivery. Birth weight was abstracted from the birth certificate. Caffeine consumption was associated with an increased risk of intrauterine growth retardation (birth weight less than the 10th percentile for sex and gestational age). For women whose average daily caffeine consumption was 0-10, 11-150, 151-300, or > 300 mg, the adjusted odds ratios for delivering a newborn with growth retardation were 1.00, 1.28 (95% confidence interval (CI) 1.04-1.59), 1.42 (95% CI 1.07-1.87), and 1.57 (95% CI 1.05-2.33), respectively. Caffeine intake, however, was not related to preterm delivery or low birth weight. We conclude that caffeine intake during pregnancy is a risk factor for intrauterine growth retardation.