Adverse neonatal outcomes: examining the risks between preterm, late preterm, and term infants

Objective

There is a relative paucity of data regarding neonatal outcomes in the late preterm cohort (34 to 36 6/7 weeks). This study sought to assess differences in adverse outcomes between infants delivering 32 to 33 6/7, 34 to 36 6/7 weeks, and 37 weeks or later.

Study Design

Data were collected as part of a retrospective cohort study of preterm labor patients (2002-2005). Patients delivering 32 weeks or later were included (n = 264). The incidence of adverse outcomes was assessed. Significant associations between outcomes and gestational age at delivery were determined using χ² analyses and Poisson regression modeled cumulative incidence and controlled for confounders.

Results

Late preterm infants have increased risk of adverse outcomes, compared with term infants. Controlling for confounders, there was a 23% decrease in adverse outcomes with each week of advancing gestational age between 32 and 39 completed weeks (relative risk 0.77, P < .001, 95% confidence interval, 0.71-0.84).

Conclusion

Further investigation regarding obstetrical management and long-term outcomes for this cohort is warranted.

Key words: adverse neonatal outcomes, late preterm infant, preterm birth, preterm labor