Stillbirth following previous cesarean section in Bavaria/Germany 1987–2005

Background An elevated risk for unexplained stillbirth in subsequent pregnancies after cesarean section was reported in 2003. This finding would imply renewed discussions about stronger indications for cesarean sections. Objective To find out whether there is an elevated risk for stillbirth in subsequent pregnancies after cesarean section in our cohort in Bavaria. Methods As data linkage of records is not possible in Germany, we devised a suitable adjustment for bias correction. Second pregnancies in Bavaria/Germany after previous vaginal birth and previous cesarean section from 1987 to 2005 were analyzed. Risk of unexplained stillbirth was estimated by time-to-event analysis. Results In our cohort of 629,815 second pregnancies, no elevated stillbirth risk in pregnancies after previous cesarean section compared to previous vaginal birth was noted (crude risk 0.22% in both groups; hazard ratio (HR) 1.00; P = 1.0). A slightly decreased risk for stillbirth after previous cesarean section for the period of 1994–2005 (HR 0.674; P = 0.04) could be shown. Conclusion We found no elevated stillbirth risk in pregnancies after previous cesarean section. The significantly lower risk for stillbirths after previous cesarean section in the period 1994–2005 is interpreted as consequence of improved obstetric surveillance. With our adjustment for bias correction, we hope to have found a way to make our data largely comparable with other sources reported in the literature. However, because of the strict German data protection act, the Bavarian birth register is only of limited use for the presented study.