Coffee consumption during pregnancy and selected congenital malformations: a nationwide case-control study.

Finland leads the world in per capita coffee consumption. To evaluate the hypothesis that coffee consumption during pregnancy is teratogenic, 755 pairs of mothers of malformed children and their controls were personally interviewed soon after delivery. After excluding tea drinkers and pairs with inadequate information, the study group included 706 pairs. Study subjects consisted of mothers of children with 112 defects of the central nervous system, 241 orofacial clefts, 210 structural defects of the skeleton, and 143 cardiovascular malformations. The coffee consumption during pregnancy was similar for the mothers of malformed or non-malformed children. The comparison of the mothers drinking at least four cups of coffee a day during pregnancy with those not consuming coffee at all showed a relative risk point estimate of 1.0 with the 95 per cent confidence limits of 0.7 and 1.3.