{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T07:11:33Z","timestamp":1790838693477,"version":"4.1.0"},"reference-count":32,"publisher":"American Academy of Pediatrics (AAP)","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2018,12,1]]},"abstract":"<jats:sec>\n                  <jats:title>OBJECTIVE:<\/jats:title>\n                  <jats:p>To examine whether changes in mortality and morbidities have benefited male more than female infants.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>METHODS:<\/jats:title>\n                  <jats:p>Infants of gestational ages 22 to 29 weeks born between January 2006 and December 2016 at a Vermont Oxford Network center in the United States were studied. We examined mortality and morbidity rate differences and 95% confidence intervals by sex and birth year. We tested temporal differences in mortality and morbidity rates between boys and girls by means of a likelihood ratio test (LRT) on nested binomial regression models with log links.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>RESULTS:<\/jats:title>\n                  <jats:p>A total of 205\u2009750 infants were studied; 97\u2009048 (47.2%) infants were girls. The rate for mortality and chronic lung disease decreased over time faster for boys than for girls (LRT P &amp;lt; .001 for mortality; P = .006 for lung disease). Restricting to centers that remained throughout the entire study period did not change all the above but additionally revealed a significant year-sex interaction for respiratory distress syndrome, with a faster decline among boys (LRT P = .04). Morbidities, including patent ductus arteriosus, necrotizing enterocolitis, early-onset sepsis, late-onset sepsis, severe intraventricular hemorrhage, severe retinopathy of prematurity, and pneumothorax, revealed a constant rate difference between boys and girls over time.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>CONCLUSIONS:<\/jats:title>\n                  <jats:p>Compared with girls, male infants born at &amp;lt;30 weeks\u2019 gestation experienced faster declines in mortality, respiratory distress syndrome, and chronic lung disease over an 11-year period. Future research should investigate which causes of death declined among boys and whether their improved survival has been accompanied by a change in their neurodevelopmental impairment rate.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1542\/peds.2018-2352","type":"journal-article","created":{"date-parts":[[2018,11,14]],"date-time":"2018-11-14T08:25:12Z","timestamp":1542183912000},"source":"Crossref","is-referenced-by-count":68,"title":["Sex Differences in Mortality and Morbidity of Infants Born at Less Than 30 Weeks\u2019 Gestation"],"prefix":"10.1542","volume":"142","author":[{"given":"Nansi S.","family":"Boghossian","sequence":"first","affiliation":[{"name":"Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Geraci","sequence":"additional","affiliation":[{"name":"Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erika M.","family":"Edwards","sequence":"additional","affiliation":[{"name":"Vermont Oxford Network, Burlington, Vermont; and"},{"name":"Departments of Mathematics and Statistics and"},{"name":"Pediatrics, College of Medicine, University of Vermont, Burlington, Vermont"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeffrey D.","family":"Horbar","sequence":"additional","affiliation":[{"name":"Vermont Oxford Network, Burlington, Vermont; and"},{"name":"Pediatrics, College of Medicine, University of Vermont, Burlington, Vermont"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"417","published-online":{"date-parts":[[2018,12,1]]},"reference":[{"issue":"6","key":"2021121022551127100_B1","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.1542\/peds.2011-3028","article-title":"Mortality and neonatal morbidity among infants 501 to 1500 grams from 2000 to 2009.","volume":"129","author":"Horbar","year":"2012","journal-title":"Pediatrics"},{"issue":"10","key":"2021121022551127100_B2","doi-asserted-by":"crossref","first-page":"1039","DOI":"10.1001\/jama.2015.10244","article-title":"Trends in care practices, morbidity, and mortality of extremely preterm neonates, 1993-2012.","volume":"314","author":"Stoll","year":"2015","journal-title":"JAMA"},{"issue":"7","key":"2021121022551127100_B3","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1056\/NEJMoa1605566","article-title":"Survival and neurodevelopmental outcomes among periviable infants.","volume":"376","author":"Younge","year":"2017","journal-title":"N Engl J Med"},{"issue":"3","key":"2021121022551127100_B4","doi-asserted-by":"crossref","first-page":"e164396","DOI":"10.1001\/jamapediatrics.2016.4396","article-title":"Variation in performance of neonatal intensive care units in the United States.","volume":"171","author":"Horbar","year":"2017","journal-title":"JAMA Pediatr"},{"issue":"4","key":"2021121022551127100_B5","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1056\/NEJMoa1403489","article-title":"Causes and timing of death in extremely premature infants from 2000 through 2011.","volume":"372","author":"Patel","year":"2015","journal-title":"N Engl J Med"},{"issue":"2","key":"2021121022551127100_B6","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1542\/peds.2013-0501","article-title":"Obstetric and neonatal care practices for infants 501 to 1500 g from 2000 to 2009.","volume":"132","author":"Soll","year":"2013","journal-title":"Pediatrics"},{"issue":"6","key":"2021121022551127100_B7","doi-asserted-by":"crossref","first-page":"1367","DOI":"10.1542\/peds.2004-2099","article-title":"Prediction of death for extremely low birth weight neonates.","volume":"116","author":"Ambalavanan","year":"2005","journal-title":"Pediatrics"},{"issue":"1","key":"2021121022551127100_B8","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1111\/j.1365-3016.2007.00780.x","article-title":"Lower mortality but higher neonatal morbidity over a decade in very preterm infants.","volume":"21","author":"de Kleine","year":"2007","journal-title":"Paediatr Perinat Epidemiol"},{"issue":"8","key":"2021121022551127100_B9","doi-asserted-by":"crossref","first-page":"898","DOI":"10.1111\/ped.13320","article-title":"Role of sex in morbidity and mortality of very premature neonates.","volume":"59","author":"Ito","year":"2017","journal-title":"Pediatr Int"},{"issue":"3","key":"2021121022551127100_B10","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1038\/pr.2011.50","article-title":"Neonatal and infant outcome in boys and girls born very prematurely.","volume":"71","author":"Peacock","year":"2012","journal-title":"Pediatr Res"},{"issue":"3","key":"2021121022551127100_B11","doi-asserted-by":"crossref","first-page":"F182","DOI":"10.1136\/fn.83.3.F182","article-title":"Sex differences in outcomes of very low birthweight infants: the newborn male disadvantage.","volume":"83","author":"Stevenson","year":"2000","journal-title":"Arch Dis Child Fetal Neonatal Ed"},{"issue":"16","key":"2021121022551127100_B12","doi-asserted-by":"crossref","first-page":"1672","DOI":"10.1056\/NEJMoa073059","article-title":"Intensive care for extreme prematurity\u2013moving beyond gestational age.","volume":"358","author":"Tyson","year":"2008","journal-title":"N Engl J Med"},{"issue":"7","key":"2021121022551127100_B13","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1097\/00006454-199807000-00004","article-title":"Incidence, presenting features, risk factors and significance of late onset septicemia in very low birth weight infants. 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