In recent years, prospective randomized trials have been undertaken comparing general anesthesia with both spinal and epidural anesthesia for cesarean delivery. In a comparison of spinal and general anesthesia for elective cesarean delivery at term, no difference was demonstrated in short-term neonatal outcomes, including Apgar scores, cord gas parameters, creatine kinase, AST/ALT and cortisol levels, hospital stay, NICU admissions, neonatal respiratory depression, or perinatal asphyxia.[3] However, in another smaller randomized study comparing general anesthesia with epidural anesthesia for cesarean delivery at term, the epidural group had higher Apgar scores, higher Neurologic Adaptive Capacity scores at 2 and 24 hours of life, higher umbilical artery pH and pO2, and a shorter interval to initiation of breastfeeding.[4] A recent large cohort study reported that for both emergency and elective cesarean deliveries, significantly more infants delivered under general anesthesia require resuscitation.[5]
It is well accepted that optimal anesthetic choice depends on the clinical situation. Comparisons of general and regional anesthesia in the setting of specific obstetric dilemmas such as prematurity, pre-eclampsia, and placenta previa have been reported. The influence of general compared with epidural anesthesia for cesarean delivery of preterm infants < 32 weeks has been described using a prospective database. When controlled for confounders, lower 1-minute Apgar scores were evident in the general anesthesia group[6]; however, the clinical significance of this in the setting of comparable 5-minute scores is unclear. Dyer and colleagues[2] published results from a prospective randomized trial comparing general anesthesia with spinal anesthesia for cesarean delivery in pre-eclamptic patients with a nonreassuring fetal heart rate tracing. Both groups had acceptable hemodynamic parameters. The spinal group received more ephedrine, had a lower maternal pCO2, and umbilical artery parameters showed a greater base deficit and lower pH. The general anesthesia group had lower 1-minute Apgar scores, but 5-minute scores were comparable. It is unclear what conclusions should be drawn from these results.
Finally, another recent prospective randomized trial evaluated the use of general vs epidural anesthesia in the setting of placenta previa. Neonatal Apgar scores did not differ between the groups; however, the general anesthesia group had lower maternal postoperative hematocrits and more blood transfusions, suggesting a maternal benefit with the use of regional anesthesia in the setting of placenta previa.[7]
Varying data exist regarding the effect of anesthetic options on neonatal Apgar scores and umbilical artery parameters, and the significance of small differences in these numbers is unclear. Each situation must be evaluated individually; however, in most cases maternal risk is greater with general anesthesia. There is some suggestion that neonatal Apgar scores are lower and resuscitation rates are higher in the setting of general anesthesia use, although the long-term clinical significance of this observation is unclear.