Long-established practices of birth assistance by knowledgeable females, reinforced in the nineteenth century by immigrant cultures, were effectively challenged in the early twentieth century by medical professionalization and concerns about health and hygiene.

Midwife-attended births fell from 40 percent in 1915 to 10.7 percent in 1935—the latter generally non-white. The Frontier Nursing Service and other programs focused on the disadvantaged sparked a new professionalization of midwifery in conjunction with nursing in the 1930s. This foundation expanded after the 1970s, when midwives came to be perceived as less intrusive, “natural,” home-based and even feminist alternatives to male-dominated obstetrics. More than 5,000 certified nurse-midwives, and other directentry practitioners (without nursing training) assist in prenatal and post-natal care for 150,000 births annually roughly 7 percent of all births in 1998. While serving rural and other areas where physicians are inaccessible, midwives tend to operate in hospitals and birthing centers rather than in homes, with limited responsibility in difficult cases.