[Significance of uterine contractions for adaptation of the newborn infant before cesarean section].

Unlabelled: There are quite a few publications on the influence of labour on the adaptation of neonates after elective cesarean sections. Many authors recommend the induction of labor prior to the cesarean section. They found that this improves the adaptation of the infants.

Material And Method: All cesarean sections between 1991 and 1996 are recorded. Mature neonates (> 36 weeks of pregnancy) were evaluated separately from premature infants (< 36 weeks of pregnancy). As target-parameters we chose 1. the condition of the neonates (characterized by the Apgar-Score, the pH of the umbilical cord artery, and the requirement of artificial respiration). 2. the necessity of transfer to the neonatologic intensive care unit. Concerning these parameters, the immature neonates (> 36 weeks of pregnancy) were evaluated separately from the mature infants (< 36 weeks of pregnancy). In the latter group we finally evaluated the data of those who were not delivered by a cesarean section because of intrauterine fetal distress.

Results: The adaptation of the premature neonates was so closely related to the gestational age that all the other variables were of no statistically significant influence. Thus also the factor "labour" was of no influence. The results in the group of the mature infants were completely different. Between week 36 und 42 of pregnancy the gestational age was of no influence on the adaptation of the neonates. Statistically noticeable however was the influence of preoperative labour: The adaptation of infants delivered by cesarean-section after labour was remarkably worse than the adaptation of those who were delivered without labour prior to the operation. This statement is also correct when one rules out those infants who were delivered by a so called emergency cesarean section. When evaluating the group of neonates in which the cesarean section was not performed because of intrauterine fetal distress we could find no influence of preoperative labour on the adaptation of the infants. All other variables examined (e.g. maternal age, parity, duration of labour, method of anaesthesia, twin-pregnancy) were no factors of influence on the adaptation of the babies.

Conclusion: From our results we cannot support the recommendation to induce labour prior to any elective cesarean section by infusion of oxytocin or to wait for the spontaneous onset of labour. There ist no reason to change our policy to perform an elective cesarean section as near as possible to term before the onset of labour.