Interinstitutional variations in mode of birth after a previous caesarean section: a cross-sectional study in six German hospitals

Aims: Regional and interinstitutional variations have been recognized in the increasing incidence of caesarean section. Modes of birth after previous caesarean section vary widely, ranging from elective repeat caesarean section (ERCS) and unplanned repeat caesarean section (URCS) after trial of labour to vaginal birth after caesarean section (VBAC). This study describes interinstitutional variations in mode of birth after previous caesarean section in relation to regional indicators in Germany. Material and methods: A cross-sectional study using the birth registers of six maternity units (n = 12,060) in five different German states (n = 370,209). Indicators were tested by chi(2) and relative deviations from regional values were expressed as relative risks and 95% confidence intervals. Results: The percentages of women in the six units with previous caesarean section ranged from 11.9% to 15.9% (P = 0.002). VBAC was planned for 36.0% to 49.8% (P = 0.003) of these women, but actually completed in only 26.2% to 32.8% (P = 0.66). Depending on the indicator, the units studied deviated from the regional data by up to 32% [relative risk 0.68 (0.47-0.97)] in respect of completed VBAC among all initiated VBAC. Conclusions: There is substantial interinstitutional variation in mode of birth following previous caesarean section. This variation is in addition to regional patterns.