The epidemiology of sudden infant death in upstate New York: II: birth characteristics.

This study describes the epidemiology of sudden infant death syndrome (SIDS) among infants born during 1974 to upstate New York residents. Birth certificate characteristics for 184 SIDS cases are compared with those of 417 infants dying from other causes in the same age range, 7-365 days. The results confirm the following as infant risk factors: fall or winter birth, low birthweight for gestational age, twin birth, and live birth order three or more. Maternal risk factors include: age under 20, abnormal uterine bleeding during pregnancy, late initiation of prenatal care, less than 12 years of education and single marital status. The increased risk for mothers who first gave birth in their teens and for second-born twins has not been previously reported. The evidence that SIDS babies are small for gestational age, that twins, especially the second born, and babies whose mothers experienced abnormal uterine bleeding during pregnancy are all at increased risk of SIDS suggests that perinatal stress leading to hypoxia is one of the components that determine the risk of SIDS.