The impact of birth anesthesia on the parameters of oxygenation and acid–base balance in umbilical cord blood

Abstract

Background: There is a great number of studies dealing with the impact of birth anesthesia on the course of labor and condition of the newborn. The aim of this study was to investigate the impact of birth anesthesia on the parameters of oxygenation and acid-base balance in umbilical cord blood.Methods: Subjects were divided into four groups: vaginal delivery without anesthesia, vaginal delivery with epidural anesthesia, delivery by cesarean section under a subarachnoid block, and delivery by cesarean section under general anesthesia. The study included mothers aged 18–45 and their newborns born from a singleton normal pregnancy lasting 37–42 weeks, calculating the date of birth according to Naegele's Rule, which was confirmed by ultrasound assessment. The inclusion criteria were a birth weight between 2800 and 4100 gResults: Hematocrit, total hemoglobin, blood oxygen capacity and carboxyhemoglobin content (umbilical artery and vein mean values respectively in all study groups: 41.9 and 42.6%, 14.3 and 14.5 g/dl, 19.3 and 19.6 ml/dl) were similar in all groups and did not correlate with pH in either group. The mean pH value of umbilical cord arterial blood in the “vaginal delivery with epidural anesthesia” group was 7.27 and was significantly the lowest (p < .05) of all the examined groups, in the remaining groups, the mean values ranged between 7.29 and 7.30. Hemoglobin oxygen saturation, oxygenated hemoglobin content, and total oxygen content in umbilical cord blood were statistically significant (p < .001), almost twice as high in cesarean sections under general anesthesia than in cases of regional anesthesia regardless of the method of delivery. Vaginal deliveries had intermediate values of oxygenation parameters.Conclusion: Blood oxygenation of the fetus is a very good parameter to evaluate the clinical state of the baby. Due to most common hypotension of the mother by the regional anesthesia (subarachnoid or epidural), which is compensated by the application of the vasoconstrictors or only by the fluids, it comes to decrease in the oxygen supply of the fetus. We consider in this study that the general anesthesia can be, in some cases, more indicated than the regional anesthesia. The decision of which kind of anesthesia should be used needs to be made by the anesthetists and also by the obstetrician because it can affect the neonatal state after the delivery. It also needs to be mentioned that the time between the start of the anesthesia and the extraction of the fetus by the cesarean section should be as short as possible.