Maternal diabetes increases the risk of both pregnancy complications and adverse birth outcomes, and there is reason to believe that it may have long-term negative health effects. A daughter's reproductive health could becompromised either by an altered intrauterine metabolic environment or genetic risk factors shared by mother and daughter. The investigators assessed the reproductive health of 739 women born in Norway in the years 1967-1982 whose mothers had pregestational diabetes. The incidence during this period was 1.6 per 1000 deliveries. The study population totalled 142,904 daughters who had delivered at least 1 child by 1998. Daughters of pregestational diabetic mothers had a lower survival rate than those whose mothers were not diabetic (89.2% vs. 97.4%). A significant difference in mortality was apparent during gestation and in the first week of life, but excess deaths were noted in offspring of diabetic mothers throughout the first year of life. In age-stratified analysis, there were no differences in the proportion of women bearing children or in the average numbers of children between daughters with and those without a diabetic mother. When analysis was limited to singleton births and stratified by the mothers' and daughters' diabetic status, a 3-fold excess in stillbirths was found in women whose mothers had pregestational diabetes (2.6%) or who themselves had pregestational diabetes (2.6%), compared to nondiabetic women with no maternal history of diabetes (0.8%). The findings were unchanged after adjusting for the daughter's maternal age and accepted obstetrical risk factors. With increasing maternal age and more prevalent obesity and type I diabetes, pregestational diabetes is expected to become more prevalent. Daughters of women with pregestational diabetes may benefit from close prepregnancy and perinatal care.