Midwifery Prenatal Care Linked to Fewer Birth Interventions

Midwifery prenatal and labor care at a freestanding birth center may be related to improved maternal and infant outcomes, according to the findings of a retrospective study by Sarah Benatar, PhD, from the Urban Institute in Washington, DC, and colleagues, who published their findings online April 16 in Health Services Research.

"Midwife-attended births have been associated with improved perinatal outcomes, including fewer interventions overall, fewer cesarean deliveries in particular, and improved patient satisfaction," the authors write. "There has been less research specifically on birth center care, or birth center care delivered to low-income or minority women, and a 2004 review of research on midwife care in birth center settings raises concerns about the quality of research on this topic and the need for well-designed studies."

In the current study, the authors reviewed birth certificate data and used propensity score modeling and instrumental variable analysis to compare maternal and infant outcomes between women who received midwifery prenatal care at a freestanding birth center and those who received usual care. The inclusion criteria were at least 2 prenatal visits, a singleton birth, and a gestational age of at least 24 weeks.

In propensity score analysis of 872 women who received midwifery care and 42,987 women who received usual care, midwifery care was associated with improvements in a number of variables, including lower rates of cesarean section (odds ratio [OR], 0.59; P < .01), electronic fetal monitoring (OR, 0.77; P < .01), and preterm birth (OR, 0.70; P < .01), as well as a higher birth weight (marginal effect, 79 g; P < .01) and a higher birth weight at term (marginal effect, 43 g; P < .01).

Similar results were obtained in instrumental variables analysis of 872 women who received midwifery care and 56,073 women who received usual care, including lower rates of cesarean section (marginal effect, −10.5; P < .01) and use of vacuum or forceps (marginal effect, −3.3; P < .01), as well as higher rates of weekend delivery (marginal effect, 11.7; P < .05) and vaginal birth after cesarean section (marginal effect, 57.7; P < .05), among women who received midwifery care.

In a subgroup analysis, black women who received midwifery care were also less likely to undergo cesarean section (OR, 0.62; P < .01) and require the use of vacuum or forceps (OR, 0.39; P < .01) and were more likely to deliver on the weekends (OR, 1.15; P < .05). In addition, midwifery care was linked to a higher birth weight (marginal effect, 67 g; P < .01) and a higher birth weight at term (marginal effect, 43 g; P < .01) for their infants.

The limitations of the study include the inclusion of a single birth center and a lack of random assignment.

"While further study is necessary, this analysis indicates that birth center care can be safe and beneficial, improving care for many women and their infants," the authors conclude.

The study was supported by funding from the Kellogg Foundation. The authors have disclosed no relevant financial relationships.

Health Serv Res. Published online April 16, 2013. Abstract