195: Late preterm births: Are they nearly term?


      To estimate the risk of short-term complications in neonates born between 34 and 36 weeks by weeks of gestation.

      Study Design

      This is a retrospective cohort study of singleton pregnancies delivered in the U.S. in 2003 between 34 and 36 weeks. Gestational age was subgrouped into 34, 35, and 36 completed weeks. Statistical comparison was performed using chi-square test and multivariable logistic regression models, with 37 weeks as the referent.


      There were 249,070 births meeting study criteria: 15.4% at 34 weeks, 27.1% at 35 weeks, and 57.5% at 36 weeks. The frequency of undesirable neonatal outcomes decreases with increasing gestational age, and neonates born at 34-36 weeks had higher odds of complications compared to deliveries at 37 weeks (see Table).


      While the risk of undesirable neonatal outcomes decrease with increasing gestational age, complication remains higher in late preterm births compared to deliveries at 37 weeks.