Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort

Abstract

Background Although preterm birth less than 37 weeks gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates. Objective We sought to describe the contemporary frequencies of neonatal death, neonatal morbidities, and neonatal length of stay across the spectrum of preterm gestational ages. Study Design Secondary analysis of an obstetric cohort of 115,502 women and their neonates who were born in 25 hospitals nationwide, 2008–2011. All live born non-anomalous singleton preterm (23.0–36.9 weeks of gestation) neonates were included in this analysis. The frequency of neonatal death, major neonatal morbidity (intraventricular hemorrhage grade III/IV, seizures, hypoxic-ischemic encephalopathy, necrotizing enterocolitis stage II/III, bronchopulmonary dysplasia, persistent pulmonary hypertension), and minor neonatal morbidity (hypotension requiring treatment, intraventricular hemorrhage grade 1/2, necrotizing enterocolitis stage 1, respiratory distress syndrome, hyperbilirubinemia requiring treatment) were calculated by delivery gestational age; each neonate was classified once by the worst outcome they met criteria for. Results 8,334 deliveries met inclusion criteria. There were 119 neonatal deaths (1.4%). 657 (7.9%) neonates had major morbidity, 3,136 (37.6%) had minor morbidity, and 4,422 (53.1%) survived without any of the studied morbidities. Deaths declined rapidly with each advancing week of gestation. This decline in death was accompanied by an increase in major neonatal morbidity, which peaked at 54.8% at 25 weeks of gestation. As frequencies of death, and major neonatal morbidity fell, minor neonatal morbidity increased, peaking at 81.7% at 31 weeks of gestation. The frequency of all morbidities fell beyond 32 weeks. Neonatal length of hospital stay decreased significantly with each additional completed week of pregnancy; among babies delivered from 26 to 32 weeks of gestation, each additional week in utero reduced the subsequent length of neonatal hospitalization by a minimum of 8 days. The median post-menstrual age at discharge nadired at 35.7 weeks post-menstrual age for babies born at 32–33 weeks of gestation. Conclusions Our data show that there is a continuum of outcomes, with each additional week for gestation conferring survival benefit while reducing the length of initial hospitalization. These contemporary data can be useful for patient counseling regarding preterm outcomes.

Relationship between Epigenetic Maturity and Respiratory Morbidity in Preterm Infants

“…24,25 Infants admitted to the neonatal intensive care unit (NICU) often require respiratory support 26 and the risk for BPD and long-term adverse effects on pulmonary function is generally higher the earlier the infant is born. 11 …”

“…Gestational age is a major determinant of neonatal morbidity and mortality, 11 including the risk of developing BPD. Gestational age is clinically determined either by the date of the last menstrual period or, more accurately, by early obstetrical ultrasound assessment.…”

Health care experiences of pregnant, birthing and postnatal women of color at risk for preterm birth

“…Social risk for PTB encompasses one or more of the social determinants described in the literature associated with the condition, such as unstable housing (Behrman and Butler, 2007), food insecurity (Hennessey et al, 2009), exposure to stress and/or stressors (Hogue and Bremner, 2005;RichEdwards and Grizzard, 2005;Gennaro et al, 2008). Whereas medical risk factors for PTB include infections during pregnancy (Behrman and Butler, 2007;Manuck et al, 2016), a prior history of PTB (Behrman and Butler, 2007), preterm labor (Behrman and Butler, 2007), and a history of previous poor birth outcomes (Behrman and Butler, 2007;Bryant et al, 2010).…”

“…It is estimated that 1 in 9 infants in the US are born too early and these infants are at risk of mortality and neonatal morbidity, with the risk inversely related to gestational age (Manuck et al, 2016). The causes of PTB remain poorly understood (Behrman and Butler, 2007).…”

Mortalidad neonatal y factores asociados en recién nacidos internados en una Unidad de Cuidados Neonatales

“…En Estados Unidos de América, Manuck et al, 14 observaron que, a menor edad gestacional, se presentaba mayor mortalidad. Cuantificaron frecuencias de muerte de 44,2% en RN de < 24 semanas de gestación y menos del 1% en neonatos de 32 o más semanas.…”