Midwife-attended births in the United States, 1990-2012: results from revised birth certificate data.

INTRODUCTION: Data on attendance at birth by midwives in the United States have been available on the national level since 1989, allowing for the documentation of long-term trends. New items on payer source and prepregnancy body mass index (BMI) from a 2003 revision of the birth certificate provide an opportunity to examine additional aspects of US midwifery practice.

METHODS: The data in this report are based on records on birth attendant gathered as part of the US National Standard Certificate of Live Birth from a public use Web site, Vital Stats (https://www.cdc.gov/nchs/VitalStats.htm), which allows users to create and download specialized tables. Analysis of new items on prepregnancy BMI and birth payer source are limited to the 38 states (86% of US births) that adopted the revised birth certificate by 2012.

RESULTS: Between 1989 and 2012, the proportion of all births attended by certified nurse-midwives (CNMs) increased from 3.3% to 7.9%. The proportion of vaginal births attended by CNMs reached an all-time high of 11.9%. Births attended by "other midwives" (typically certified professional midwives) rose to a peak of 28,343, or 0.7% of all US births. The distribution of payer source for CNM-attended births (44% Medicaid; 44% private insurance; 6% self-pay) is very similar to the national distribution, whereas the majority (53%) of births attended by other midwives are self-pay. Women whose births are attended by other midwives are less likely (13%) to have a prepregnancy BMI in the obese range than women attended by CNMs (19%) or overall (24%).

DISCUSSION: The total number of births attended by CNMs and other midwives has remained steady or grown at a time when total US births have declined, resulting in the largest proportions of midwife-attended births in the quarter century that such data have been collected.