Comment on “Cerebral Palsy Risk by Combined Apgar Score and Umbilical Cord Blood pH Levels”

Cerebral palsy (CP) is one of the most common childhood motor disabilities. While the causes of CP are unclear, perinatal hypoxia from impaired oxygen supply during birth may be one potential cause. Low 5-minute Apgar score and umbilical cord blood pH are clinical and biochemical measures that may indicate acute perinatal hypoxia associated with CP. Previous studies have assessed these measures separately. The aim of this study was to examine whether a low Apgar score combined with umbilical cord blood pH measures can predict perinatal hypoxia associated with CP.

This was a population-based cohort study based on data from Danish national registries. Included were all liveborn, singleton newborns ≥35 weeks of gestation between 2004 and 2018. Excluded were those with chromosomal abnormalities, major congenital malformations, or a birthweight <2000 g, or who died or emigrated in the first year of life. Apgar scores were categorized into 3 groups: 0-3, 4-6, and 7-10. Umbilical cord blood pH was categorized into 4 groups: <7.00, 7.00-7.09, 7.10-7.19, and ≥7.20. The primary outcome was a confirmed diagnosis of CP.

A total of 799 children diagnosed with CP were included in the analysis. Among newborns who had the lowest Apgar score (0-3) with a low pH (<7.00), 22 children (15.2% of 145) were diagnosed with CP (aRR, 159.2; 95% CI, 104.1-243.5). In those with a low pH <7.00 and normal Apgar score (7-10), 14 children (0.6% of 2463) were diagnosed with CP (aRR, 6.1; 95% CI, 3.7-10.2). In children with low Apgar score (0-3) and normal pH (≥7.20), 8 children (2.1% of 388) were diagnosed with CP (aRR, 22.4; 95% CI, 11.5-43.5). Severe CP was more likely in children with low pH and low Apgar scores versus those without perinatal hypoxia (49.2% vs 10.1%; P <0.001).

In conclusion, an increased risk of CP was observed when the combination of clinical and biochemical measures indicated perinatal hypoxia, especially when both measures were low.

(Summarized from Pedersen MV, Lindhard MS, Moster D, et al. Cerebral palsy risk by combined Apgar score and umbilical cord blood pH levels. JAMA Netw Open . 2026;9(2):e2559359. doi:10.1001/jamanetworkopen.20).