# Association of the dose of maternal general anaesthesia during Caesarean delivery with 5-minute Apgar scores: a retrospective single centre cohort study

## TL;DR

This study found that higher doses of general anesthesia during C-sections may slightly lower newborn Apgar scores, but the effect is modest and could be linked to maternal blood pressure.

## Contribution

The study introduces a novel analysis of the total general anesthesia dose using EMAC-AUC and its association with neonatal Apgar scores.

## Key findings

- Every 5-MAC-minute increase in EMAC-AUC was linked to a 10% higher odds of a 5-min Apgar score <7.
- The association weakened after adjusting for maternal hypotension (MAP80AUC).
- Maintaining maternal blood pressure above 80 mm Hg may help reduce low Apgar scores.

## Abstract

Neuraxial anaesthesia is preferred for Caesarean deliveries, but general anaesthesia is used in situations such as emergencies, contraindications to neuraxial anaesthesia, or anticipated complex deliveries. Although previous research has examined how the duration of fetal general anaesthesia exposure affects neonatal outcomes, the total dose of general anaesthesia has not been studied. The primary aim was to determine the association, if any, between the general anaesthesia dose and 5-min neonatal Apgar scores. We hypothesised that greater maternal exposure to general anaesthesia would be associated with lower neonatal 5-min Apgar scores.

This retrospective single centre cohort study evaluated the association between total maternal general anaesthesia dose and 5-min Apgar scores among neonates born via planned Caesarean delivery under general anaesthesia between January 2013 and March 2022. Total general anaesthesia dose was quantified using the area under the curve of effective minimum alveolar concentration (EMAC-AUC) from general anaesthesia induction to neonatal delivery (T). Multivariable logistic regression adjusted for maternal age, gestational age, and maternal hypertension. Maternal blood pressure was quantified by the area under the curve for mean arterial pressure <80 mm Hg (MAP80AUC).

Analysis included 101 neonates born via planned Caesarean delivery under maternal general anaesthesia. Every 5-MAC-minute increase in EMAC-AUC was associated with a 10% increase in the adjusted odds of a 5-min Apgar score of <7 (odds ratio, 1.10; 95% confidence interval, 1.05–1.22; P <0.001). However, this association was not significant after adjusting for maternal MAP80AUC (odds ratio, 1.05; 95% confidence interval, 1.00–1.16; P=0.177).

In this cohort of preterm, late preterm, and term neonates delivered via planned CD or Caesarean hysterectomy, total general anaesthetic dose was statistically associated with the 5-min Apgar score, although the clinical effect was modest. The attenuation of the EMAC-AUC association after adjusting for MAP80AUC suggests that maternal hypotension may play an important explanatory role, although causality cannot be inferred. Maintaining mean arterial pressure >80 mm Hg may reduce the likelihood of low Apgar scores, although prospective studies are needed to confirm this relationship.