In a retrospective study of ten epidemics of measles in virgin-soil populations in Greenland, 368 women were found to be pregnant at the time of their infection with measles. Information on the course of the pregnancies was obtained in 327 of these women and a clinical examination was made of 252 of their children. The risk of fetal death among women infected in the first trimester was found to be high. About half of 20 women infected during their first two months of pregnancy and a fifth of 31 women infected in the third month had abortions. 9% of 64 women infected in the first trimester and going to term had stillbirths. 28 women infected in the first two months of pregnancy had live children, but four of these had congenital malformations, three of extreme rarity and severity, leading to death. The rate of perinatal mortality and prematurity was equal among infants exposed to measles in the first, second and third trimester of fetal life.