OBJECTIVE:

To compare midwifery and medical care practices and measure optimal perinatal outcomes using a new clinimetric instrument.

DESIGN:

Prospective descriptive cohort design.

SETTING:

A large, inner city obstetric service with medical and midwifery services.

PARTICIPANTS:

Three hundred seventy-five of 400 consecutively enrolled patients were participated (25 excluded due to extreme risk status or missing data); 92% were of minority race/ethnicity and 54% had less than a high school education. Of the 375 patients, 179 received physician care and 196 received nurse-midwife care.

MAIN OUTCOME MEASURES:

The Optimality Index-US was measured. Health record data were extracted and scored using the Optimality Index-US to summarize the optimality of processes and outcomes of care as well as the woman's preexisting health status.

RESULTS:

Midwifery patients had more optimal care processes (less use of technology and intervention) with no difference in neonatal outcomes, even when preexisting risk was taken into account.

CONCLUSION:

Even among moderate-risk patients, the midwifery model of care with its limited use of interventions can produce outcomes equivalent to or better than those of the biomedical model.