The primary aim of this research is to compare the charges incurred by the productions processes used by each of two providers of maternity care, certified nurse-midwives (CNMs) and obstetricians (OBs) while controlling for risk status at the beginning of pregnancy. The second aim is to determine whether the charges associated with maternity care are influenced by provider group or by consumer preferences.

Subjects for the study are 505 women who enroll in either the Nurse-Midwifery Service (33%) or women of equal risk status who select obstetricians (66%) in private practice at a tertiary medical center. Comprehensive charge data were collected from hospital billing records and from professional service charge records. In this setting the fee for care is the same whether it was delivered by a CNM or by an OB. Consumer preferences were determined from questionnaire data completed approximately 6 weeks before the anticipated birth of the infant.

Results showed that CNM charges were almost 17% ($1,460) less per case than the charges of OBs. The hospital charges of CNM clients were almost 21% ($1,112) less than the hospital charges of the OBs with a lesser savings (10% or $348) in professional service fees. There were no significant differences between OBs and CNMs in the baby charges.

The results of this study indicate that CNM clients did have preferences which were significantly different from the obstetrician patients on four measures of practice. OB patients were more likely to "definitely want" ultrasound, pain medication in labor, electronic fetal monitoring, and the use of stirrups. However, provider group was found to be a stronger predictor of charges than were consumer preferences.

If the cost savings found in this setting at today's prices were applied nationally to the 70% of women who meet the low to moderate risk criteria of the nurse-midwifery service, an annual savings of over $4 billion could be realized.