基于婴儿期日龄分期的新生儿后期新概念

目的：通过调查新生儿期（0~28 d）、新生儿后期（~100 d）和改良婴儿期（~1岁）病死率和死因谱，为新生儿后期新概念提供初步的临床证据支持。方法：在中国西部新生儿协作网采用整群随机抽样方法抽取14家医院，采用回顾性横断面调查方法，采集14家医院2004年1月至2013年12月住院婴儿新生儿期、新生儿后期和改良婴儿期的第一出院的或病死的诊断。结果：在10年期间，共有155 463例住院婴儿进入本文分析，死亡959例，病死率为6.16‰；新生儿期、新生儿后期和改良婴儿期病死率分别为10.1‰、6.9‰和2.6‰，新生儿后期与新生儿期和改良婴儿期差异均有统计学意义。新生儿期632例死亡病例中前6个死亡原因依次为新生儿窒息、新生儿呼吸窘迫综合征（NRDS）、先天心脏病（CHD）、早产相关疾病（PAD）、婴儿猝死综合征(SIDS)和肺炎，新生儿后期148例死亡病例中前6个死亡原因依次为肺炎、CHD、PAD、腹泻、SIDS和维生素K1缺乏，改良婴儿期188例死亡病例中前6个死亡原因依次为肺炎、CHD、意外伤害、SIDS、PAD和腹泻。新生儿期、新生儿后期和改良婴儿期同时出现的死因性疾病PAD、肺炎、SIDS和CHD，病死率最高是新生儿后期(P＜0.001)。结论：在未校正胎龄和喂养方式混杂因素的情况下，新生儿后期疾病病死率及其病因具有特殊性，可能具有特别的临床意义。

Post-newborn period: a new concept of age period in early life after birth

ObjectiveThe early life after birth, is very important to growth/development of children and health/disease of adult.However, the age boundary is inconsistent among pediatrician nowadays.The aim of the present study was to investigate the mortalities and causes of death of the neonatal period, post-newborn period(28 days after birth~100 days) and modified infant period(100 days after birth~1 year)for the new concept in early life after birth with post-newborn period.MethodsWe reviewed retrospectively the dead children of fourteen hospitals in west China from 2004 to 2013 and investigated the mortalities and causes of death of the neonatal period, post-newborn period and modified infant period.ResultsDuring 2004-2013, 155 463 infants aged 0 to 1 year were admitted to the hospitals, and 959 died.The total infant mortality was 6.16%.Significant differences were found in the mortality among the three periods (10.1% vs 6.9% vs 2.6%, P<0.001).Three main causes of death were different among three period: they were neonatal respiratory distress syndrome, neonatal asphyxia and congenital heart disease (CHD) in the neonatal period, pneumonia, CHD and premature-associated disease (PAD) in the post-newborn period, and pneumonia, CHD and accidental injuries in the modified infant period.Otherwise, four major diseases simultaneously appearing during the three periods(PAD, pneumonia, sudden infant death syndrome and CHD) showed inverse "U" shape changes from the neonatal period to the modified infant period, and the highest mortality occurred in the post-newborn period (P<0.001).ConclusionWithout gestational age and feeding mode being corrected as confounding factors, the mortality and etiology of post-newborn period have particularity, and which may mean special clinical values.In the future, more studies are needed to clarify the new-built concept and interpret its importance.