Cord Length, Umbilical Artery Lactate Concentration and Perinatal Outcomes of Babies with Nuchal Cord at Ile-Ife, Nigeria

Background: There is inconclusive evidence on the relevance of the nuchal cord in obstetric practice. Objectives: This study aims to evaluate the umbilical artery lactate concentration and perinatal outcomes of babies born with a nuchal cord. Methods: In a cross-sectional study at the Obafemi Awolowo University Teaching Hospital, babies born with a nuchal cord at term and matched controls without a nuchal cord were recruited between January 2017 and December 2018. Gestational age at delivery, meconium-stained liquor, foetal heart rate abnormalities, Caesarean section rates, cord lengths and umbilical artery lactate concentrations were compared. The umbilical artery lactate concentration was assayed with the Lactate-Plus®; neonatal acidosis was defined as cord lactate concentration > 4.9mmol/L. Results: One hundred and forty-four babies with nuchal cords and 144 controls were recruited. The prevalence of nuchal cord was 3.4%, with 80% of the babies having a single loop. Babies with nuchal cords had longer mean cord length (57.7cm vs 45.4cm; p<0.01), higher mean umbilical artery lactate (4.93mmol/L vs 3.48mmol/L; p = 0.04), meconium-stained liquor (16% vs 3.2%; Relative risk = 4.6), more babies with  Apgar score <7 at fifth minute (9 versus 4 babies) and increased perinatal mortality (55.5/1000 births vs 13.8/1,000 births; Relative risk = 4). There was a positive correlation between cord length and the number of nuchal loops (r = 0.5, p<0.01). Conclusions: Nuchal cord is associated with abnormal cord lactate concentration and adverse perinatal outcomes. Prenatal reporting may enhance intrapartum surveillance and improve perinatal outcomes.