Caffeine ingestion during pregnancy: in utero exposure and possible effects.

The vast majority of fetuses are exposed to one or more of the methylxanthines, primarily caffeine, often at frequent intervals, during gestation. Caffeine has a multitude of pharmacologic actions and its effects must be determined on the fetus and newborn in the immediate future for suggestive evidence links caffeine with such fetal and newborn pathology as pre- and postmaturity and intrauterine growth retardation. Since both caffeine and theophylline have markedly prolonged and variable half-lives especially in the premature infant, the possibility of prolonged effects from these drugs cannot be dismissed.