Late-preterm birth in a level III hospital: incidence and associated morbidity

Abstract

Introduction: Late-preterm infants are physiologically and metabolically immature and have important risk of morbidity and mortality. Aim: To analyze the incidence of late prematurity and its associated morbidity and mortality at a level III hospital between 2011 and 2013. Methods: This was a descriptive and retrospective study of infants born between 34 + 0/7 and 36 + 6/7 weeks’ gestation and its associated morbidity and mortality. Medical records were reviewed. Results: In a 3-year period there were 8,458 births of witch 513 (6.1%) were late-preterm infants. Of these, 99/513 (19.3%) had 34 weeks’ gestation, 145/513 (28.3%) had 35 weeks’ gestation and 269/513 (52.4%) had 36 weeks’ gestation. Late-preterm birth rate was 5.7% in 2011, 6.9% in 2012 and 5.6% in 2013 (p = 0.08). In relation to birth weight, 269 (52.4%) of late-preterm infants had low birth weight. There was an association between gestational age and birth weight (p = 0.002). Of the 513 late-preterm infants, 177 (34.5%) were admitted to the Neonatal Intensive Care Unit (NICU) and more often at 34 weeks’ gestation (69/99, 69.7%) than at 35 (57/145, 39.3%) and 36 (51/269, 19.0%) weeks’ gestation (p < 0.001). Most frequent clinical diagnoses were hyperbilirubinemia (112/177, 63.3%), feeding difficulties (111/177, 62.7%), transient tachypnea of the newborn (71/177, 40.1%), hypoglycemia (38/177, 21.5%), intrauterine growth restriction (33/177, 18.6%). Average length of hospitalization was 12 days. Newborns of 34 weeks’ gestation were longer admitted than newborns of 35 and 36 weeks’ gestation (15.3 vs 9.8 vs 10.8 days; p = 0.002). There was one death due to sepsis after surgical correction of gastroschisis. Conclusion: The incidence of late-preterm birth remained stable between 2011 and 2013. Late-preterm hospitalization rate in the NICU was 34.5%. Hyperbilirubinemia, feeding difficulties and respiratory disease were the main diagnosis. Late-preterm of 34 weeks’ gestation were admitted more frequently and for longer periods than the remaining newborns. It’s important to pay particular attention to this group of infants.

Keywords

• late-preterm infant
• birth rate
• birth weight
• immature
• morbidity
• mortality