Umbilical cord blood acid–base analysis at birth and long‐term neurodevelopmental outcomes in children: a systematic review and meta‐analysis

Abstract

Background Umbilical cord blood acid–base sampling is routinely performed at many hospitals. Recent studies have questioned this practice and the association of acidosis with cerebral palsy. Objective To investigate the associations between the results of umbilical cord blood acid–base analysis at birth and long‐term neurodevelopmental outcomes and mortality in children. Search strategy We searched six databases using the search strategy: umbilical cord AND outcomes. Selection criteria Randomised controlled trials, cohorts and case–control studies from high‐income countries that investigated the association between umbilical cord blood analysis and neurodevelopmental outcomes and mortality from 1 year after birth in children born at term. Data collection and analysis We critically assessed the included studies, extracted data and conducted meta‐analyses comparing adverse outcomes between children with and without acidosis, and the mean proportions of adverse outcomes. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach. Main results We have very low confidence in the following findings: acidosis was associated with higher cognitive development scores compared with non‐acidosis (mean difference 5.18, 95% CI 0.84–9.52; n = two studies). Children with acidosis also showed a tendency towards higher risk of death (relative risk [RR] 5.72, 95% CI 0.90–36.27; n = four studies) and CP (RR 3.40, 95% CI 0.86–13.39; n = four studies), although this was not statistically significant. The proportion of children with CP was 2.39/1000 across the studies, assessed as high certainty evidence. Conclusion Due to low certainty of evidence, the associations between umbilical cord blood gas analysis at delivery and long‐term neurodevelopmental outcomes in children remains unclear.

ST waveform analysis vs cardiotocography alone for intrapartum fetal monitoring: An updated systematic review and meta‐analysis of randomized trials

“…We argue that the relationship between metabolic acidosis and harder outcomes is questionable. There is a known relationship between low cord artery pH values and serious outcome, but the threshold remains unknown 40,41 . Few neonates with severe acidemia appear to have sequelae, particular those who are healthy at birth, and most neonates with adverse outcomes, also those with seizures, are not born acidemic 28,42 .…”

“…There is a known relationship between low cord artery pH values and serious outcome, but the threshold remains unknown. 40 , 41 Few neonates with severe acidemia appear to have sequelae, particular those who are healthy at birth, and most neonates with adverse outcomes, also those with seizures, are not born acidemic. 28 , 42 Recent studies also report that umbilical artery pH and base excess are poor predictors of short‐term outcomes as low 5‐minute Apgar score and long‐term neurodevelopmental morbidity.…”