[The learning curve in the context of the cesarean section].
We created learning curves to define an objective figure according to which residents are capable of performing a cesarean section responsibly without supervision. We established learning curves of 9 different outcome variables related to cesarean section for all trainees of obstetrics-gynecology in the years 1995-1999 (blood loss, length of stay, Apgar score, umbilical cord pH value, induction-delivery time, uterotomy-delivery time and total operation time). The change from the steep to the flat part of the curve was determined visually and defined as the end of the initial learning phase. 15 residents performed a total of 371 sections. Concerning the operation time and the induction-delivery time, the steep part of the curve was exceeded after 20 sections. For the 1-min Apgar score and the length of stay, only a slight change in the curve was present; for the remaining parameters, no learning process could be demonstrated. For cesarean sections of average risk, 20 procedures are adequate to provide sufficient safety for the patient.