Anesthesia for Cesarean Section???Effects on Neonates

The effects of general and regional anesthesia on neonates after cesarean section have been studied mainly on elective cases. In this paper we studied infants delivered by elective and nonelective cesarean section at the Winnipeg Women's Hospital from 1975 to 1983 (n = 3940) to determine the effect of anesthetic technique on neonatal outcomes. A trained anesthesia nurse interviewed all parturients and reviewed their antepartum, labor and delivery, and anesthesia records. Assessments of neonatal outcomes were based on 1− and 5-minute Apgar scores, need for positive pressure oxygen by mask or intubation, and neonatal deaths (within 30 days). These outcomes were determined in three subgroups of neonates delivered by cesarean section: those delivered by elective section, those delivered by urgent cesarean section for dystocia or failure of labor to progress, and those delivered by section because of fetal distress. Overall, 12.5% of the infants had 1-minute Apgar scores of 4 or less, and 1.4% had 5-minute Apgar scores of 4 or less. Neonates born to mothers given general anesthesia had worse outcomes than those born to mothers given regional anesthesia. Among neonates delivered after elective section, general anesthesia was associated with a higher incidence of low Apgar scores at 1 minute. In neonates delivered by nonelective section, general anesthesia was associated with higher rates of low Apgar scores at 1 and 5 minutes as well as greater requirements for intubation and artificial ventilation. There were no differences seen in neonatal death rates with general and regional anesthesia in the three groups. Using a multivariate analysis to control for differences among neonates with regard to maternal age, parity, presence of antepartum disease, labor complications, presence of fetal distress, gestational age, multiple birth, use of narcotics or sedatives during labor, elective versus nonelective section, and year of birth, the risk of poor neonatal outcome remained greater after general anesthesia than after regional anesthesia. We conclude that infants delivered by cesarean section under general anesthesia are more likely to be depressed and more likely to require active resuscitation than those delivered by cesarean section with regional anesthesia. However, with appropriate neonatal care, the choice of anesthetic technique does not appear to affect neonatal survival in the short term.