Objective: To study whether the selection of low risk parturient women into a separate maternity unit leads to a lower risk of emergency cesarean section, compared to giving birth in a unit with mixed cases.
Design: Hospital based registry study.
Setting: Maternity units in two university hospitals in Oslo, Norway.
Population: All low risk parturient women with attempted vaginal deliveries in the years 2001-2003, a total number of 11,686 deliveries.
Methods: Data were obtained from standardized patient records and risks of cesarean section were estimated as odds ratios.
Main outcome measures: Emergency cesarean section risk.
Results: Compared with women giving birth in a unit with mixed cases, women giving birth in a maternity unit with low risk cases only had a higher risk of emergency cesarean section (OR 1.4; 95% CI 1.2-1.6).
Conclusions: Giving birth in a low risk maternity unit is associated with a higher risk of cesarean section for low risk parturient women compared with giving birth in a maternity unit with mixed cases.