Comment on “Apgar Score Plus Umbilical Artery pH and Adverse Neonatal Outcomes in Very Preterm Infants”

Very preterm (VPT) infants born <32 weeks’ gestation are at high risk for severe neonatal morbidity that can persist long-term. The ability to accurately estimate the risk for adverse outcomes in VPT infants remains a challenge. While the 5-minute Apgar score has been widely used in term infants to assess this risk, this measure alone may not reliably predict adverse outcomes in VPT infants. The umbilical artery pH (UA-pH), used to determine fetal oxygen supply in the period immediately before birth, is another measure for assessing newborns’ condition and could improve risk assessments in VPT infants. The aim of this study was to examine whether combining UA-pH values with 5-minute Apgar scoring improved the accuracy of estimating the risk for adverse neonatal outcomes in VPT infants.

This was a population-based cohort study from the Effective Perinatal Intensive Care in Europe (PICE) study, which included all stillbirths and live births from 11 geographically and organizationally diverse countries between April 2011 and September 2012. For this analysis, all live births from 22 to 31 weeks’ gestation with data on 5-minute Apgar score and UA-pH were included. Apgar scores were classified as <7 or ≥7, and UA-pH values as low (<7.20) and normal (≥7.20). The combined variables were Apgar score <7 and UA-pH <7.20; Apgar score <7 and UA-pH ≥7.20; Apgar score ≥7 and UA-pH <7.20; and Apgar score ≥7 and UA-pH ≥7.20. The primary outcome was a composite of mortality and/or any adverse morbidity, including intraventricular hemorrhage (IVH) >grade 2, cystic periventricular leukomalacia, necrotizing enterocolitis, retinopathy of prematurity, and moderate or severe bronchopulmonary dysplasia (BPD).

A total of 4147 VPT infants were included in the analysis. Among them, 18.1% had an Apgar score <7 and 13.5% had low UA-pH (<7.20). Combining these variables, 4.7% had an Apgar score <7 and low UA-pH, 8.8% had an Apgar score ≥7 and low UA-pH, and 13.4% had an Apgar score <7 and normal UA-pH. Infants with an Apgar score <7 and a low UA-pH were at the highest risk of the composite outcome (55.1%). Infants with an Apgar score of ≥7 and a low UA-pH were more likely to experience the composite outcome than those with an Apgar score of ≥7 and normal UA-pH (25.6% vs. 19.5%). The risk of death was higher in infants with an Apgar score <7 and a low UA-pH [adjusted risk ratio (ARR), 2.4; 95% CI, 1.7-3.3] than in those with normal UA-pH (ARR, 2.0; 95% CI, 1.6-2.6). Infants with an Apgar score ≥7 and low UA-pH had a comparable risk of death as those with normal UA-pH (ARR, 1.2; 95% CI, 0.8-1.8); however, the risk of IVH was higher in these infants versus those with normal UA-pH (ARR, 1.6; 95% CI, 1.1-2.3). Only one of the subcategories identified for this study showed an association; the risk of BPD was higher in infants with an Apgar score of <7 and normal UA-pH (ARR, 1.4; 95% CI, 1.2-1.7).

In conclusion, combining the 5-minute Apgar score and UA-pH measures to assess newborn’s condition improved the ability to predict certain adverse neonatal outcomes, including mortality and severe IVH, in VPT infants.

(Summarized from Ehrhardt H, Behboodi S, Maier RF, et al. Apgar score plus umbilical artery pH and adverse neonatal outcomes in very preterm infants. JAMA Netw Open . 2026;9(2):e2557913. doi:10.1001/jamanetworkopen.2025.57913).