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

Abstract

Aim: 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.