The relationship of maternal weight status to the probability of appearance of one or a combination of three or more undesirable pregnancy events (UPE) was analyzed. A total of 711 women presenting for prenatal care before 16 weeks estimated gestational age were categorized according to early pregnancy body mass (EPBM) and subsequent weight gain. Statistical analysis revealed weight gain related to the appearance of one UPE only in women with an EPBM less than 120 pounds. In gestations complicated by three or more UPEs, a relationship to weight gain was shown only in women with an EPBM of 120–199 pounds.