Association between Regional Labour Analgesia and Neonatal Heart Rate Immediately after Birth

Regional analgesia is widely used for labour pain relief. The impact on foetal heart rates has been extensively studied, but little is known about its impact on neonatal heart rates. The aim of this study was to assess whether maternal use of epidural, spinal, or pudendal labour analgesia was associated with differences in neonatal heart rates.

This Norwegian observational study included 1,281 singleton cephalic term vaginal deliveries from September 1, 2019, to June 30, 2021. Neonatal heart rates were measured using dry electrode technology. Generalised linear models adjusted for covariates related to the mother, neonate, and labour process were used to estimate neonatal heart rates by methods of maternal analgesia at 30 s, 1, 2, and 3 min after birth. The results were compared to a baseline representing heart rates modelled for infants whose mothers received no analgesia.

The median heart rate in all groups, including the epidural (n = 439), spinal (n = 34), pudendal (n = 36), and no analgesia (n = 772) groups, ranged from 147 to 175 beats per minute (bpm) at all time points. Infants whose mother received epidural analgesia had slightly higher mean heart rate compared to the baseline at 2 (167 vs. 164 bpm) and 3 (152 vs. 149 bpm) minutes of life (p < 0.05). No significant association was observed between spinal or pudendal analgesia and neonatal heart rates.

Infants whose mothers received epidural labour analgesia had statistically, but not clinically significant, higher heart rates in the first minutes of life.