324: Gestational age and circumstances at delivery affect neonatal outcomes among late preterm infants.

Abstract

Late preterm (LP) infants are often considered as a homogeneous population more susceptible to neonatal morbidities, despite significant differences due to gestational age at delivery (GA9 and circumstances prompting parturition. Therefore, we intended to asses if among LP newborns, timing of delivery and circumstances at parturition could affect early neonatal outcomes. Prospective, area based cohort study of neonatal morbidity and mortality among singleton infants born between 34+0 and 36+6 weeks, at 19 L&D units in Emilia Romagna county, Italy, during 2013-15. After univariate analysis, multivariate logistic regression was used to determine the OR af a composite adverse neonatal outcome (including Apgar 5' ≤ 3, umbilical-cord-blood arterial pH < 7.0, RDS, TTN, hypoglycemia, sepsis, confirmed seizures, stroke, IVH, cardiopulmonary resuscitation, invasive respiratory support and hospitalization ≥ 5 days) according to GA at delivery (34, 35 or 36 weeks) and circumstances at parturition (spontaneous LP labor, pPROM or indicated LP delivery), while accounting for other maternal and prenatal characteristics. Among 1897 births, 302, 505 and 1061 infants were born at 34, 35 and 36 weeks, respectively. There were no neonatal deaths. According to univariate analysis (table 1), the composite adverse neonatal outcome significantly decreased with GA (p< 0.01), while circumstances at parturition did not differ when birth occurred at 34, 35 or 36 weeks. Adjusted OR for perinatal morbidities were higher at 34 (p< 0.01) and 35 (p< 0.01) weeks when compared to 36 weeks deliveries, and among indicated LP births (p< 0.01) (table 2). Neonatal morbidities in LP infants differ according to both GA and indication for delivery. Such differences may be useful when counseling patients and planning interventions.View Large Image Figure ViewerDownload Hi-res image Download (PPT)