title: Survival of pre-viable preterm infants in the United States: a systematic review and meta-analysis.
abstract: The objective of this paper is to review observational studies that addressed the survival of pre-viable gestations in the United States. We searched PubMed, Ovid, CINAHL, and Web of Knowledge for studies reporting survival of infants born at <24 gestational weeks and/or <500g in the United States and published between January 2003 and January 2013. The full texts of 70 articles were examined and a total of 15 studies qualified and were selected. We analyzed fixed-effect and random-effects models for eight studies on survival to discharge. Pooled survival to discharge in the random-effects model was 45.9% (95% CI: 41.1-51.7) and 39.7% in the fixed-effect model (95% CI: 38.8-40.7). Studies differed by pre-viable survival measures and epochs (1985-2009). Protective factors included antenatal corticosteroids, neonatal resuscitation, and intensive care. The current survival threshold for pre-viable infants warrants reconsideration of the limits of viability. Protective factors that enhance survival should be considered in the management of these infants.
authors.affiliation: Maternal & Child Health Comparative Effectiveness Research Group, Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, 13201 Bruce B. Downs Blvd, MDC 56, Tampa, FL 33612; Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, College of Medicine, University of South Florida, Tampa, FL. Electronic address: hsalihu@health.usf.edu.
authors.forename: Hamisu M
authors.initials: HM
authors.lastname: Salihu
authors.forename: Abraham A
authors.initials: AA
authors.lastname: Salinas-Miranda
authors.forename: Latoya
authors.initials: L
authors.lastname: Hill
authors.forename: Kristen
authors.initials: K
authors.lastname: Chandler
mesh_terms: D005260:Female; D005328:Fetal Viability; D006801:Humans; D007226:Infant Mortality; D052577:Infant, Extremely Low Birth Weight; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007234:Infant, Premature; D008430:Maternal-Child Health Centers / Q000458:organization & administration*; D011050:Policy Making; D011247:Pregnancy; D016019:Survival Analysis; D015996:Survival Rate; D014481:United States / Q000453:epidemiology
keywords: Extremely low birth weight; Extremely preterm birth; Periviable; Pre-viable; Pregnancy; Survival