Mortalidad perinatal en el parto prematuro entre 22 y 34 semanas en un hospital público de Santiago, Chile

Abstract

Objetivo: Conocer la mortalidad perinatal del parto prematuro y los factores de riesgo asociados, usando los datos perinatales clínicos, los resultados de laboratorio y los hallazgos patológicos del feto, neonato y placenta. Métodos: Estudio retrospectivo, cohorte de 407 nacimientos prematuros, únicos, entre 22.0 y 34.0 semanas de gestación. Se estudiaron las muertes fetales y neonatales hasta los 7 días de vida. Fallecieron 122 niños (64 muertes fetales y 58 neonatales), 78 tuvieron autopsia. Resultados: La mortalidad perinatal fue de 30% (122/407). El 71% (87/122) de las muertes ocurrieron antes de las 30 semanas y el 81% (99/122) en nacidos con peso menor de 1500 gramos. Las principales causas de muerte perinatal según el factor asociado con el parto prematuro fueron: infección bacteriana ascendente (IBA) 41% (50/122), anomalía congénita 20% (24/122) e hipertensión arterial 12% (15/122). Los factores de riesgo de muerte perinatal, identificados mediante análisis de regresión logística, fueron: edad gestacional al parto (pAim: To determine perinatal mortality of premature birth and the risk factors associated using perinatal clinical data, laboratory results and histopathological fetal, neonatal and placental findings. Methods: Retrospective cohort study of 407 preterm single births at 22.0-34.0 weeks gestation. Fetal and neonatal deaths until 7 days of life were studied. One hundred and twenty two children died (64 fetal deaths and 58 neonatal deaths), 78 had autopsy. Results: Perinatal mortality was 30% (122/407). Of total deaths, 71% (87/122) occurred before 30 weeks gestation and 81% (99/122) occurred in very low birth weight infants (<1500 g). The main causes of perinatal mortality according to associated factors for premature birth were: ascending bacterial infection (ABI) 41% (50/122), congenital anomalies 20% (24/122) and hypertension 12% (15/122). Risk factors for perinatal mortality, identified by logistic regression analisis were: births at gestational age p<0.001, congenital anomalies p<0.001, ABI p=0.02 and hypertension p=0.03. The major causes of perinatal death were: hypoxia produced by diverse conditions (acute or chronic) 28%, congenital infections 23% (mostly congenital pneumonia 18%), abruptio placentae with hypoxia and hypovolemic shock 18%, congenital anomalies 18% and hypertensive syndrome with acute or chronic hypoxia 7%. Conclusions: In gestations between 22.0-34.0 weeks, premature birth caused by ABI was the most important cause of perinatal death, gestational age at birth was identified as the major risk factor for mortality and hypoxia the main cause of death.

Keywords

• Mortalidad perinatal
• nacimiento prematuro
• infección congénita
• Perinatal mortality
• premature birth
• congenital infection