Williams CM, et al. - Among women in the United States with registered birth records, researchers investigated the association between previous cesarean delivery and subsequent preterm birth in the second pregnancy via conducting a retrospective cohort study utilizing United States birth certificate data to generate the study population, which consisted of women delivering a singleton infant in their second live birth in the year 2016. Data reported that this small, but statistically significant relationship between the previous cesarean section and subsequent preterm birth implies that efforts to decrease the number of index cesarean sections might contribute to decreasing the overall preterm birth rate in the United States.