Genetic Associations With Gestational Duration and Spontaneous Preterm Birth

( N Engl J Med . 2017;377(12):1156–1167) Preterm birth is the leading cause of death in neonates and children younger than 5 years of age. Its definition, birth before 37 completed weeks of gestation, is a dichotomous trait based on a somewhat arbitrary cutoff of weeks’ gestation, rather than time of birth or a level of fetal maturity. Therefore, in the present study, the authors tested genetic associations with gestational duration (a...