MIDWIFERY CARE, SOCIAL AND MEDICAL RISK-FACTORS, AND BIRTH OUTCOMES IN THE USA

Study objective-To determine if there are significant differences in b irth outcomes and survival for infants delivered by certified nurse mi dwives compared with those delivered by physicians, and whether these differences, if they exist, remain after controlling for sociodemograp hic and medical risk factors. Design-Logistic regression models were u sed to examine differences between certified nurse midwife and physici an delivered births in infant, neonatal, and postneonatal mortality, a nd risk of low birthweight after controlling for a variety of social a nd medical risk factors. Ordinary least squares regression models were used to examine differences in mean birthweight after controlling for the same risk factors. Study setting-United States. Patients-The stud y included all singleton, vaginal births at 35-43 weeks gestation deli vered either by physicians or certified nurse midwives in the United S tates in 1991. Main results-After controlling for social and medical r isk factors, the risk of experiencing an infant death was 19% lower fo r certified nurse midwife attended than for physician attended births, the risk of neonatal mortality was 33% lower, and the risk of deliver ing a low birthweight infant 31% lower, Mean birthweight was 37 grams heavier for the certified nurse midwife attended than for physician at tended births. Conclusions-National data support the findings of previ ous local studies that certified nurse midwives have excellent birth o utcomes. These findings are discussed in light of differences between certified nurse midwives and physicians in prenatal care and labour an d delivery care practices. Certified nurse midwives provide a safe and viable alternative to maternity care in the United States, particular ly for low to moderate risk women.