Umbilical artery lactate level as a predictor of perinatal outcome at Mulago National Referral Hospital

Abstract

Introduction: In 2017 global burden of neonatal mortality was 18 deaths per 1000 live births with over 39% of this burden in sub-Saharan Africa. Birth asphyxia is one of the leading causes of neonatal mortality and morbidity and lactic acid could be an accurate indicator of newborn asphyxia. The adoption of this indicator could improve newborn care and help attain the Sustainable Development Goal of reducing neonatal mortality to at least as low as 12 per 1000 live births by 2030.

Objective: To determine the accuracy of Umbilical Artery Lactate in predicting perinatal outcome and factors associated with high Umbilical Artery Lactate in neonates born at Mulago National Referral Hospital

Materials and methods: The study was conducted at Mulago National Referral Hospital labor suite from January to March 2019 and was a prospective cohort design. 720 mothers and their babies were recruited into the study. Following birth, an umbilical artery blood sample (2 mL) was taken from a double-clamped segment of cord and the lactate measured using a point of care device; Accutrend Plus System. Maternal and neonatal characteristics and outcomes were recorded.

Results: During the study, there were 579 vaginal deliveries (18 instrumental) and 141 cesarean sections which met the inclusion criteria. 41 babies had an Apgar score less than 7 at 5 minutes, with an optimal cutoff for lactate of 6.05 mmol/L (Se 92.68%, Sp 76.58%). 82 babies were admitted to the special care unit and the optimal cutoff for this outcome was 6.05 mmol/L (Se 75.61%, Sp 78.84%). 54 babies were diagnosed with HIE with an optimal cutoff of 6.05 mmol/L (Se 96.30%, Sp 78.23%). There were 19 neonatal deaths and the optimal cutoff was 10.05 mmol/L (Se 73.68%, Sp 96.01). The following factors were associated with an increased likelihood of high lactate in a neonate: male sex (OR = 1.71; 95%CI 1.16–2.54; P<0.05), primigravidity (OR = 2.78; 95%CI 1.89-4.08; P < 0.001), Meconium staining Grade I (OR = 3.31; 95%CI 2.09-5.23 P<0.001), Grade II (OR = 11.28; 95%CI 6.41-20.22; P < 0.001), Grade III (OR = 16.64; 95%CI 8.00-36.71; P < 0.001) and, Administration of oxytocin (OR = 1.97; 95%CI 1.00-3.77; P<0.05).

Conclusion: Umbilical lactate can be used as a measure of intrapartum hypoxia with reasonable sensitivity and specificity for the prediction of neonatal outcome.