{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T23:54:42Z","timestamp":1793318082849,"version":"4.5.0"},"reference-count":39,"publisher":"American Medical Association (AMA)","issue":"8","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA Netw Open"],"abstract":"\n Importance<\/jats:title>\n Umbilical cord pH (UC-pH) level is an important objective indicator of intrapartum fetal hypoxia and is used to predict neonatal morbidity and mortality. A UC-pH value of less than 7.00 is often defined as a threshold for severe acidosis, but existing evidence is divergent and largely based on UC-pH measurements from selected populations; consequently, the results are challenging to interpret.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n To investigate the association between UC-pH levels and the risk of adverse neonatal outcomes in a national setting with universal UC-pH measurement.<\/jats:p>\n <\/jats:sec>\n \n Design, Setting, and Participants<\/jats:title>\n This national, population-based cohort study included all liveborn, singleton, full-term infants without malformations born in Denmark from January 1, 2012, to December 31, 2018. Data were analyzed from January 1, 2023, to March 1, 2024.<\/jats:p>\n <\/jats:sec>\n \n Exposure<\/jats:title>\n Umbilical cord pH level categorized as less than 7.00, 7.00 to 7.09, 7.10 to 7.19 and 7.20 to 7.50 (reference group).<\/jats:p>\n <\/jats:sec>\n \n Main Outcomes and Measures<\/jats:title>\n The primary outcome was a composite of severe adverse neonatal outcomes: neonatal death, therapeutic hypothermia, mechanical ventilation, treatment with inhaled nitric oxide, or seizures. Secondary outcomes were individual components of the primary outcome, Apgar score, respiratory outcomes, and hypoglycemia. Data are presented as adjusted risk ratios (ARRs) with 95% CIs.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n Among the 340 431 infants included, mean (SD) gestational age was 39.9 (1.6) weeks; mean (SD) birth weight was 3561 (480) g; and 51.3% were male. Umbilical cord pH of less than 7.20 was observed more often among infants with a gestational age of 40 or 41 weeks (31.6%-33.6% compared with 18.2%-20.2% at a gestational age of 39 weeks) and among male infants (53.9%-55.4% vs 44.6%-46.1% among female infants). Compared with the pH reference group (576 of 253 540 [0.2%]), the risk for the primary outcome was increased for the groups with UC-pH levels of less than 7.00 (171 of 1743 [9.8%]), 7.00 to 7.09 (101 of 11 904 [0.8%]), and 7.10 to 7.19 (259 of 73 244 [0.4%]). Comparable patterns were observed for the individual outcomes, except for neonatal death, which was only increased in the group with UC-pH levels of less than 7.10. The risk of treatment with continuous positive airway pressure was increased when UC-pH levels were less than 7.20, and the risk of hypoglycemia was 21.5% if UC-pH levels were less than 7.10.<\/jats:p>\n <\/jats:sec>\n \n Conclusions and Relevance<\/jats:title>\n In this cohort study of 340 431 newborn infants, results support and extend previous studies indicating a higher risk of adverse outcomes even at UC-pH levels above 7.00. The threshold for more intensive observation and treatment may be reconsidered.<\/jats:p>\n <\/jats:sec>","DOI":"10.1001\/jamanetworkopen.2024.27604","type":"journal-article","created":{"date-parts":[[2024,8,14]],"date-time":"2024-08-14T11:03:28Z","timestamp":1723633408000},"page":"e2427604","source":"Crossref","is-referenced-by-count":30,"title":["Umbilical Cord pH Levels and Neonatal Morbidity and Mortality"],"prefix":"10.1001","volume":"7","author":[{"given":"Charlotte Brix","family":"Andersson","sequence":"first","affiliation":[{"name":"Danish Center for Health Services Research, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark"},{"name":"Department of Obstetrics and Gynaecology, Aalborg University Hospital, Thisted, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claus","family":"Klingenberg","sequence":"additional","affiliation":[{"name":"Department of Paediatrics, University Hospital of North Norway, Troms\u00f8"},{"name":"Research Group for Child and Adolescent Health, Department of Clinical Medicine, The Arctic University of Norway, Troms\u00f8"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Line","family":"Thellesen","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology, Herlev Hospital, University of Copenhagen, Herlev, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S\u00f8ren Paaske","family":"Johnsen","sequence":"additional","affiliation":[{"name":"Danish Center for Health Services Research, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulrik Schi\u00f8ler","family":"Kesmodel","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology, Aalborg University Hospital, Aalborg, Denmark"},{"name":"Department of Clinical Medicine, Aalborg University, Aalborg, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jesper Padkaer","family":"Petersen","sequence":"additional","affiliation":[{"name":"Department of Paediatrics, Aarhus University Hospital, Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10","published-online":{"date-parts":[[2024,8,14]]},"reference":[{"key":"zoi240853r1","doi-asserted-by":"publisher","first-page":"c1471","DOI":"10.1136\/bmj.c1471","article-title":"Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis.","volume":"340","author":"Malin","year":"2010","journal-title":"BMJ"},{"issue":"10","key":"zoi240853r2","doi-asserted-by":"publisher","first-page":"1156","DOI":"10.1111\/bjo.v130.10","article-title":"Umbilical cord blood acid-base analysis at birth and long-term neurodevelopmental outcomes in children: a systematic review and meta-analysis.","volume":"130","author":"Myrhaug","year":"2023","journal-title":"BJOG"},{"key":"zoi240853r3","doi-asserted-by":"publisher","first-page":"16","DOI":"10.3389\/fped.2017.00016","article-title":"Understanding the full spectrum of organ injury following intrapartum asphyxia.","volume":"5","author":"LaRosa","year":"2017","journal-title":"Front Pediatr"},{"issue":"8","key":"zoi240853r4","doi-asserted-by":"publisher","first-page":"692","DOI":"10.1001\/archpediatrics.2011.43","article-title":"Whole-body hypothermia for term and near-term newborns with hypoxic-ischemic encephalopathy: a randomized controlled trial.","volume":"165","author":"Jacobs","year":"2011","journal-title":"Arch Pediatr Adolesc Med"},{"issue":"14","key":"zoi240853r5","doi-asserted-by":"publisher","first-page":"1349","DOI":"10.1056\/NEJMoa0900854","article-title":"Moderate hypothermia to treat perinatal asphyxial encephalopathy.","volume":"361","author":"Azzopardi","year":"2009","journal-title":"N Engl J Med"},{"issue":"15","key":"zoi240853r6","doi-asserted-by":"publisher","first-page":"1574","DOI":"10.1056\/NEJMcps050929","article-title":"Whole-body hypothermia for neonates with hypoxic-ischemic encephalopathy.","volume":"353","author":"Shankaran","year":"2005","journal-title":"N Engl J Med"},{"issue":"4","key":"zoi240853r7","doi-asserted-by":"publisher","first-page":"F377","DOI":"10.1136\/archdischild-2017-313078","article-title":"Re-examining the arterial cord blood gas pH screening criteria in neonatal encephalopathy.","volume":"103","author":"Vesoulis","year":"2018","journal-title":"Arch Dis Child Fetal Neonatal Ed"},{"issue":"5","key":"zoi240853r8","doi-asserted-by":"publisher","DOI":"10.1001\/jamanetworkopen.2024.9119","article-title":"Whole-body hypothermia vs targeted normothermia for neonates with mild encephalopathy: a multicenter pilot randomized clinical trial.","volume":"7","author":"Montaldo","year":"2024","journal-title":"JAMA Netw Open"},{"issue":"6","key":"zoi240853r9","doi-asserted-by":"publisher","first-page":"2021","DOI":"10.1016\/j.ajog.2004.04.026","article-title":"Umbilical cord pH and base excess values in relation to adverse outcome events for infants delivering at term.","volume":"191","author":"Victory","year":"2004","journal-title":"Am J Obstet Gynecol"},{"issue":"7","key":"zoi240853r10","doi-asserted-by":"publisher","first-page":"824","DOI":"10.1111\/bjo.2012.119.issue-7","article-title":"The relationship between umbilical cord arterial pH and serious adverse neonatal outcome: analysis of 51 519 consecutive validated samples.","volume":"119","author":"Yeh","year":"2012","journal-title":"BJOG"},{"issue":"2","key":"zoi240853r11","doi-asserted-by":"publisher","first-page":"265.e1","DOI":"10.1016\/j.ajog.2022.04.037","article-title":"The association of fetal acidemia with adverse neonatal outcomes at time of scheduled cesarean delivery.","volume":"227","author":"Bligard","year":"2022","journal-title":"Am J Obstet Gynecol"},{"issue":"1","key":"zoi240853r12","doi-asserted-by":"publisher","first-page":"20","DOI":"10.1186\/s13052-020-0786-8","article-title":"Predict respiratory distress syndrome by umbilical cord blood gas analysis in newborns with reassuring Apgar score.","volume":"46","author":"De Bernardo","year":"2020","journal-title":"Ital J Pediatr"},{"issue":"7","key":"zoi240853r13","doi-asserted-by":"publisher","first-page":"854","DOI":"10.1111\/aogs.v102.7","article-title":"Implementation of universal umbilical cord pH analysis in Denmark: a national register-based study.","volume":"102","author":"Andersson","year":"2023","journal-title":"Acta Obstet Gynecol Scand"},{"issue":"7","key":"zoi240853r15","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1177\/1403494810387965","article-title":"The Danish Civil Registration System.","volume":"39","author":"Pedersen","year":"2011","journal-title":"Scand J Public Health"},{"issue":"3","key":"zoi240853r17","doi-asserted-by":"publisher","first-page":"254","DOI":"10.1038\/jp.2016.207","article-title":"Population-based reference curve for umbilical cord arterial pH in infants born at 28 to 42 weeks.","volume":"37","author":"Ski\u00f6ld","year":"2017","journal-title":"J Perinatol"},{"key":"zoi240853r18","doi-asserted-by":"publisher","first-page":"479","DOI":"10.2147\/CLEP","article-title":"The Danish Fetal Medicine database.","volume":"8","author":"Ekelund","year":"2016","journal-title":"Clin Epidemiol"},{"issue":"2","key":"zoi240853r19","doi-asserted-by":"publisher","first-page":"145","DOI":"10.1002\/uog.2017.50.issue-2","article-title":"Fetal anemia.","volume":"50","author":"Abbasi","year":"2017","journal-title":"Ultrasound Obstet Gynecol"},{"issue":"2","key":"zoi240853r20","doi-asserted-by":"publisher","first-page":"200","DOI":"10.1111\/aogs.v101.2","article-title":"Risk of complications in the late vs early days of the 42nd week of pregnancy: a nationwide cohort study.","volume":"101","author":"Andersson","year":"2022","journal-title":"Acta Obstet Gynecol Scand"},{"issue":"1","key":"zoi240853r21","doi-asserted-by":"publisher","first-page":"49.e1","DOI":"10.1016\/j.ajog.2007.06.011","article-title":"The relationship between intrapartum maternal fever and neonatal acidosis as risk factors for neonatal encephalopathy.","volume":"198","author":"Impey","year":"2008","journal-title":"Am J Obstet Gynecol"},{"issue":"1","key":"zoi240853r22","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1111\/aogs.v99.1","article-title":"Association between fetal sex, birthweight percentile and adverse pregnancy outcome.","volume":"99","author":"Voskamp","year":"2020","journal-title":"Acta Obstet Gynecol Scand"},{"issue":"11","key":"zoi240853r23","doi-asserted-by":"publisher","first-page":"2005","DOI":"10.2337\/dc09-0656","article-title":"Obstetric and perinatal outcomes in type 1 diabetic pregnancies: a large, population-based study.","volume":"32","author":"Persson","year":"2009","journal-title":"Diabetes Care"},{"issue":"11","key":"zoi240853r24","doi-asserted-by":"publisher","first-page":"1098","DOI":"10.1001\/jama.2020.12698","article-title":"Estimating risk ratios and risk differences: alternatives to odds ratios.","volume":"324","author":"Holmberg","year":"2020","journal-title":"JAMA"},{"issue":"7","key":"zoi240853r25","doi-asserted-by":"publisher","first-page":"702","DOI":"10.1093\/aje\/kwh090","article-title":"A modified Poisson regression approach to prospective studies with binary data.","volume":"159","author":"Zou","year":"2004","journal-title":"Am J Epidemiol"},{"issue":"1","key":"zoi240853r26","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1186\/s12874-018-0519-5","article-title":"Comparing performance between log-binomial and robust Poisson regression models for estimating risk ratios under model misspecification.","volume":"18","author":"Chen","year":"2018","journal-title":"BMC Med Res Methodol"},{"issue":"8","key":"zoi240853r27","doi-asserted-by":"publisher","first-page":"984","DOI":"10.1093\/aje\/kwr183","article-title":"Performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data.","volume":"174","author":"Yelland","year":"2011","journal-title":"Am J Epidemiol"},{"issue":"1","key":"zoi240853r28","doi-asserted-by":"publisher","first-page":"40","DOI":"10.1002\/mpr.v20.1","article-title":"Multiple imputation by chained equations: what is it and how does it work?","volume":"20","author":"Azur","year":"2011","journal-title":"Int J Methods Psychiatr Res"},{"issue":"8398","key":"zoi240853r30","doi-asserted-by":"publisher","first-page":"311","DOI":"10.1016\/S0140-6736(84)92685-0","article-title":"Hyperinsulinism in asphyxiated and small-for-dates infants with hypoglycaemia.","volume":"2","author":"Collins","year":"1984","journal-title":"Lancet"},{"key":"zoi240853r31","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1016\/j.jpeds.2022.01.051","article-title":"Hypoglycemia in infants with hypoxic-ischemic encephalopathy is associated with additional brain injury and worse neurodevelopmental outcome.","volume":"245","author":"Parmentier","year":"2022","journal-title":"J Pediatr"},{"issue":"12","key":"zoi240853r32","doi-asserted-by":"publisher","first-page":"1135","DOI":"10.1001\/jama.2022.2456","article-title":"Hypoglycemia in the newborn and neurodevelopmental outcomes in childhood.","volume":"327","author":"Rozance","year":"2022","journal-title":"JAMA"},{"issue":"5","key":"zoi240853r33","doi-asserted-by":"publisher","first-page":"353","DOI":"10.1111\/dmcn.2003.45.issue-5","article-title":"The acidosis paradox: asphyxial brain injury without coincident acidemia.","volume":"45","author":"Hermansen","year":"2003","journal-title":"Dev Med Child Neurol"},{"issue":"2","key":"zoi240853r34","doi-asserted-by":"publisher","first-page":"279","DOI":"10.1097\/AOG.0000000000000923","article-title":"Metabolic acidemia in live births at 35 weeks of gestation or greater.","volume":"126","author":"Morgan","year":"2015","journal-title":"Obstet Gynecol"},{"issue":"5","key":"zoi240853r35","doi-asserted-by":"publisher","first-page":"574","DOI":"10.1038\/s41390-018-0169-7","article-title":"Neonatal encephalopathy versus hypoxic-ischemic encephalopathy.","volume":"84","author":"Molloy","year":"2018","journal-title":"Pediatr Res"},{"issue":"9","key":"zoi240853r36","doi-asserted-by":"publisher","first-page":"938","DOI":"10.1111\/aogs.v101.9","article-title":"Neonatal encephalopathy\u2014controversies and evidence.","volume":"101","author":"Mehta","year":"2022","journal-title":"Acta Obstet Gynecol Scand"},{"issue":"1","key":"zoi240853r37","doi-asserted-by":"publisher","first-page":"66","DOI":"10.1002\/ijgo.12502","article-title":"Umbilical cord arterial base deficit and arterial pH as predictors of adverse outcomes among term neonates.","volume":"142","author":"Knutzen","year":"2018","journal-title":"Int J Gynaecol Obstet"},{"issue":"4","key":"zoi240853r38","doi-asserted-by":"publisher","first-page":"756","DOI":"10.1097\/AOG.0000000000000466","article-title":"Umbilical cord arterial lactate compared with pH for predicting neonatal morbidity at term.","volume":"124","author":"Tuuli","year":"2014","journal-title":"Obstet Gynecol"},{"issue":"16","key":"zoi240853r39","doi-asserted-by":"publisher","first-page":"121","DOI":"10.2147\/CLEP.S441123","article-title":"Validation of obstetric diagnosis and procedure codes in the Danish National Patient Registry in 2017.","volume":"16","author":"Herskind","year":"2024","journal-title":"Clin Epidemiol"},{"key":"zoi240853r14","unstructured":"Danish Births Register. Danish Health Data Agency. Accessed December 10, 2023. https:\/\/sundhedsdatastyrelsen.dk\/da\/registre-og-services\/om-de-nationale-sundhedsregistre\/graviditet-foedsler-og-boern\/foedselsregisteret"},{"key":"zoi240853r16","unstructured":"Guideline. Danish Society of Obstetrics and Gynecology. Accessed December 10, 2023. https:\/\/static1.squarespace.com\/static\/5467abcce4b056d72594db79\/t\/5c84e7be8165f5cb5fb3e309\/1552213956671\/Fosteroverv%C3%A5gningunderf%C3%B8dsel.pdf"},{"key":"zoi240853r29","unstructured":"Landsd\u00e6kkende kliniske retningslinjer (paediatri.dk). Danish Paediatric Society. Accessed May 24, 2024. https:\/\/paediatri.dk\/images\/dokumenter\/retningslinjer_2022\/C%C3%B8liaki_150121_REV_151122_.pdf"}],"container-title":["JAMA Network Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/articlepdf\/2822219\/andersson_2024_oi_240853_1723563151.97099.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,8,14]],"date-time":"2024-08-14T11:03:31Z","timestamp":1723633411000},"score":1,"resource":{"primary":{"URL":"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/fullarticle\/2822219"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,14]]},"references-count":39,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2024,8,1]]}},"URL":"https:\/\/doi.org\/10.1001\/jamanetworkopen.2024.27604","relation":{},"ISSN":["2574-3805"],"issn-type":[{"value":"2574-3805","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,14]]}}}