Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcome

Background Maternal caffeine consumption during pregnancy may have adverse effects on fetal, neonatal and maternal outcomes. Objectives This review investigates the effects of restricting caffeine intake by mothers on fetal, neonatal and pregnancy outcomes. Search strategy We searched the Cochrane Pregnancy and Childbirth Group's Trials Register ( December 2008), scanned bibliographies of published studies and corresponded with investigators. Selection criteria Randomised controlled trials including quasi-randomised controlled trials (RCTs) investigating the effect of caffeine and/ or supplementary caffeine versus restricted caffeine intake or placebo on pregnancy outcome. Data collection and analysis The two review authors independently assessed trial quality and extracted data. Main results One study met the inclusion criteria. Caffeinated instant coffee ( 568 women) was compared with decaffeinated instant coffee ( 629 women) and it was found that reducing the caffeine intake of regular coffee drinkers (3+ cups/day) during the second and third trimester by an average of 182 mg/day did not affect birthweight or length of gestation. Authors' conclusions There is insufficient evidence to confirm or refute the effectiveness of caffeine avoidance on birthweight or other pregnancy outcomes. There is a need to conduct high-quality, double-blinded RCTs to determine whether caffeine has any effect on pregnancy outcome. PLAIN LANGUAGE SUMMARY Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcome Caffeine is a stimulant found in tea, coffee, cola, chocolate and some over-the-counter medicines. Conflicting results found in the literature make it difficult for health professionals to advise pregnant women about avoiding caffeine during pregnancy. Clearance of caffeine from the mother's blood slows down during pregnancy. Some authors of observational studies have concluded that caffeine intake is harmful to the fetus, causing growth restriction, reduced birthweight, preterm birth or stillbirth. The newborn could also have withdrawal symptoms if the mother has a high intake of caffeine ( more than eight cups of coffee per day). Only one controlled study was identified. The study was based in Denmark. Women less than 20 weeks pregnant were randomly assigned to drinking caffeinated instant coffee ( 568 women after exclusions) or decaffeinated instant coffee ( 629 women). Drinking three cups of coffee a day in early pregnancy had no effect on birthweight, preterm births or growth restriction. Sufficient evidence is not available from randomised controlled trials to support any benefits from avoiding caffeine during pregnancy.