Abstract
OBJECTIVE: Birth asphyxia is one of the leading causes of death for neonates worldwide. Lack of an objective cost effective test to predict poor newborn outcomes at birth affects the ability to respond appropriately. This study determined predictive values of umbilical cord arterial lactate in relation to adverse neonatal outcomes. METHODS: This was a cross-sectional analytical study conducted between March 2018 and March 2019 at two hospitals in Northern Uganda. A total of 2655 women admitted for birth and their newborns were recruited. At birth, umbilical cord arterial blood was tested for lactate using the Nova Biomedical StatStrip Xpress meter. Apgar scores were assessed at 5 min by trained research midwives. Area under the receiver operator characteristics curve (AUROC) was calculated relating umbilical arterial lactate (UAL) levels and four outcomes. We modeled the best lactate cutoff level associated with the highest AUROC for the four outcomes. RESULTS: The estimated AUROC for lactate was: 88.42% for Apgar score <7 at 5 min, 83.35% for resuscitation with bag and mask, 84.55% for oxygen therapy after resuscitation and 87.72% for admission to neonatal care unit. The UAL cutoff value of 5.5 mmol/L was associated with the best AUROC of between 75.81% to 81.75% for the four adverse outcomes with no significant differences when adjusted for infectious disease parameters. The sensitivity, specificity, PPV, and NPV were; 78.95%, 86.48%, 23.54%, and 98.73% for Apgar scores <7 at 5 min, 64.40%, 88.11%, 36.59%, and 95.87% for resuscitation with bag and mask, 67.17%, 87.20%, 30.23%, and 96.99% for oxygen therapy after resuscitation, and 77.17%, 86.15%, 22.27%, and 98.65% for admission to the special care unit, respectively. CONCLUSION: Umbilical cord lactate point-of-care (POC) estimate of ≥5.5 mmol/L predicts adverse neonatal outcomes. This test may be used to trigger early interventions and intensified neonatal care complementing the clinical Apgar score assessment in settings like Uganda.