Outcomes for the First Year of Ontario's Birth Center Demonstration Project.

The comparison was not randomised, and women choosing a birth center may have been more motivated for low-intervention birth, which could affect intervention rates. Only 495 birth center admissions were included, and the two centers had different admission rules, including one accepting one previous cesarean birth and one restricting admission to prepregnancy body mass index less than 40. Safety was hard to measure because serious adverse events are rare in low-risk populations, and the study could not obtain hospital discharge data on transfusion, hysterectomy, or sepsis within the evaluation period. Potential severe maternal morbidity cases were identified using proxy measures, so the threshold for review may have been lower than originally planned. No comparator safety data were obtained for the matched hospital cohort, so the evaluation mainly describes birth center safety rather than directly comparing safety with hospital births. Breastfeeding and normal birth rates may have been underreported because of data entry design in the registry. The higher transport rate may reflect a cautious approach in a new clinical setting and a higher proportion of nulliparous admissions.

The authors declared no conflicts of interest.

Do not conclude that birth centers are safer than hospital births. The study did not obtain the same safety outcomes for the matched hospital cohort, and the lower intervention rates may reflect self-selection by women seeking low-intervention birth.