Materials and Methods
We utilized data from the National Center for Health Statistics of the US Centers for Disease Control and Prevention (CDC) birth certificate data for 2010–2012, the most recent data available to analyze the 4 ACOG/AAP clinical criteria for planned home births. The CDC files contain detailed information on each of the approximately 4 million births in the United States each year.
Data on patient characteristics including birth setting, method of delivery, birth attendant, gestational age, infant birthweight, maternal age, history of prior cesarean delivery, and parity are reported on birth certificates filed each year with each of the states in the United States and compiled by National Center for Health Statistics. These data are publicly accessible on the Internet ( http://205.207.175.93/vitalstats/ReportFolders/ReportFolders.aspx ), where detailed tables can be created and downloaded for further evaluation.
According to CDC data, “almost all the home births attended by certified nurse-midwives⁄certified midwives (98%) or “other” midwives (99%) were planned,” and therefore, we defined planned home births as births attended at home by midwives. We excluded from planned home births those performed at home by others (eg, family members, emergency medical service, or police, taxi drivers as well as unattended births).
Planned US midwife home deliveries for the years 2010–2012, the most recent years available, were analyzed for ACOG and AAP perinatal risk factors that should be excluded from home births : vaginal breech deliveries, prior cesarean delivery, twin gestations, and postdate pregnancies (gestational age 41 weeks or longer). Hospital births attended by certified nurse midwives served as a reference. Home birth–planned midwife-attended deliveries were compared with hospital-certified nurse midwives (CNM)–attended deliveries.
The CDC database separates midwives into CNM and other midwives. The AMCB certifies 2 kinds of midwives: CNMs and certified midwives (CMs), both of whom have graduated from a midwifery education program accredited by the American Commission for Midwifery Education. The total number of AMCB-certified midwives (CNMs plus CMs) includes only a small percentage of CMs because CMs are permitted to practice in only 5 states. Therefore, the CDC designation of CNMs captures nearly all of AMCB-certified midwives.
In addition to CNMs, the CDC also has a designation of other midwives, which includes certified professional midwives, who are not eligible for certification by the AMCB and who have no requirement of a Bachelor’s degree or graduate training. In addition, the CDC designation of other midwives may include lay midwives and others without any graduate midwifery training. We performed a subanalysis and compared the frequency with which certain perinatal risk factors were associated with home births attended by CNMs with those attended by other midwives (ie, midwives not eligible to get certified by the AMCB).
Data were abstracted from the US birth certificate data. Because nonidentifiable data from a publicly available data set were used, this study was not considered human subject research and did not require review by the Institutional Review Board of Weill Medical College of Cornell University.
Statistical analyses were conducted for comparisons between planned midwife-attended home births and CNM-attended deliveries in the hospital. Odds ratios and 95% confidence intervals were calculated for each of the 3 provider groups (CNM-attended home birth, other midwife-attended home birth, and CNM-attended hospital birth) and 4 of the risk groups. All statistical analyses were conducted in OpenEpi.
Results
Between 2010 and 2012, there were a total of 11,905,817 deliveries in the United States, of which 736,070 were attended by CNMs in the hospital. There were 85,318 home births (0.71% of all births in the United States) and after exclusion of 29,178 home birth deliveries performed by others, we included 56,140 deliveries that were attended by midwives at home and are considered planned midwife-attended home births. CNMs attended 19,263 (34.3%) of these home births, whereas other midwives attended 36,877 (65.7%) of planned home births.
Table 1 shows the comparisons of perinatal risk factors between deliveries attended in the hospital by CNMs and planned midwife-attended home births by CNMs and other midwives. Of the midwife-attended planned home births, approximately 3 in 10 were at a gestation of 41 weeks or longer, 1 in 156 were births with twins, approximately 1 in 23 were vaginal births after cesarean deliveries, and 1 in 135 home births were births with breech presentation.
| Risk factor | Hospital births | Home births | ||||||
|---|---|---|---|---|---|---|---|---|
| CNM-attended (n = 736,070), % (n) | CNM-attended (n = 19,263), % (n) | Other MW-attended (n = 36,877), % (n) | All MW-attended (n = 56,140), % (n) | MW-attended home births vs CNM-attended hospital births, OR (95% CI) | CNM-attended home births vs CNM-attended hospital births, OR (95% CI) | Other MW-attended home births vs CNM-attended hospital births, OR (95% CI) | Other MW-attended home births vs CNM-attended home births, OR (95% CI) | |
| Vaginal breech | 0.23 (1716) | 0.61 (118) | 0.81 (298) | 0.74 (416) | 3.19 (2.87–3.56) | 2.64 (2.19–3.18) | 3.49 (3.08–3.94) | 1.32 (1.07–1.64) |
| Prior cesarean delivery | 2.11 (15,455) | 3.99 (767) | 4.6 (1696) | 4.4 (2463) | 2.08 (2.0–2.17) | 1.93 (1.8–2.08) | 2.25 (2.14–2.37) | 1.15 (1.06–1.26) |
| Twins | 0.31 (2276) | 0.52 (101) | 0.69 (256) | 0.64 (357) | 2.06 (1.84–2.31) | 1.7 (1.39–2.08) | 2.25 (1.98–2.57) | 1.33 (1.05–1.67) |
| Postdates ≥41 wks | 18.59 (136,729) | 27.7 (5320) | 28.45 (10,435) | 28.19 (15,755) | 1.71 (1.68–1.74) | 1.67 (1.62–1.73) | 1.73 (1.69–1.77) | 1.03 (0.99–1.06) |
| Postdates ≥42 wks | 6.91 (50,848) | 9.08 (1744) | 9.73 (3567) | 9.5 (5311) | 1.41 (1.37–1.45) | 1.34 (1.28–1.41) | 1.44 (1.39–1.5) | 1.08 (1.01–1.14) |
Planned home births attended by CNMs and other midwives had a significantly higher frequency of certain perinatal risks when compared with CNM-attended hospital births. Planned home births attended by non–AMCB-certified other midwives had a significantly higher frequency of perinatal risks for breech presentation, prior cesarean deliveries, and twins, when compared with planned home births attended by CNMs.
Results
Between 2010 and 2012, there were a total of 11,905,817 deliveries in the United States, of which 736,070 were attended by CNMs in the hospital. There were 85,318 home births (0.71% of all births in the United States) and after exclusion of 29,178 home birth deliveries performed by others, we included 56,140 deliveries that were attended by midwives at home and are considered planned midwife-attended home births. CNMs attended 19,263 (34.3%) of these home births, whereas other midwives attended 36,877 (65.7%) of planned home births.
Table 1 shows the comparisons of perinatal risk factors between deliveries attended in the hospital by CNMs and planned midwife-attended home births by CNMs and other midwives. Of the midwife-attended planned home births, approximately 3 in 10 were at a gestation of 41 weeks or longer, 1 in 156 were births with twins, approximately 1 in 23 were vaginal births after cesarean deliveries, and 1 in 135 home births were births with breech presentation.
| Risk factor | Hospital births | Home births | ||||||
|---|---|---|---|---|---|---|---|---|
| CNM-attended (n = 736,070), % (n) | CNM-attended (n = 19,263), % (n) | Other MW-attended (n = 36,877), % (n) | All MW-attended (n = 56,140), % (n) | MW-attended home births vs CNM-attended hospital births, OR (95% CI) | CNM-attended home births vs CNM-attended hospital births, OR (95% CI) | Other MW-attended home births vs CNM-attended hospital births, OR (95% CI) | Other MW-attended home births vs CNM-attended home births, OR (95% CI) | |
| Vaginal breech | 0.23 (1716) | 0.61 (118) | 0.81 (298) | 0.74 (416) | 3.19 (2.87–3.56) | 2.64 (2.19–3.18) | 3.49 (3.08–3.94) | 1.32 (1.07–1.64) |
| Prior cesarean delivery | 2.11 (15,455) | 3.99 (767) | 4.6 (1696) | 4.4 (2463) | 2.08 (2.0–2.17) | 1.93 (1.8–2.08) | 2.25 (2.14–2.37) | 1.15 (1.06–1.26) |
| Twins | 0.31 (2276) | 0.52 (101) | 0.69 (256) | 0.64 (357) | 2.06 (1.84–2.31) | 1.7 (1.39–2.08) | 2.25 (1.98–2.57) | 1.33 (1.05–1.67) |
| Postdates ≥41 wks | 18.59 (136,729) | 27.7 (5320) | 28.45 (10,435) | 28.19 (15,755) | 1.71 (1.68–1.74) | 1.67 (1.62–1.73) | 1.73 (1.69–1.77) | 1.03 (0.99–1.06) |
| Postdates ≥42 wks | 6.91 (50,848) | 9.08 (1744) | 9.73 (3567) | 9.5 (5311) | 1.41 (1.37–1.45) | 1.34 (1.28–1.41) | 1.44 (1.39–1.5) | 1.08 (1.01–1.14) |
Planned home births attended by CNMs and other midwives had a significantly higher frequency of certain perinatal risks when compared with CNM-attended hospital births. Planned home births attended by non–AMCB-certified other midwives had a significantly higher frequency of perinatal risks for breech presentation, prior cesarean deliveries, and twins, when compared with planned home births attended by CNMs.
Comment
The AAP and ACOG previously published policy statements on planned home birth with recommendations when to consider planned home birth, and they listed the use of strict selection criteria for planned home births ( Tables 2 and 3 ). According to the ACOG, selection criteria for home births include singletons, cephalic pregnancies between 37 and 41 weeks, no prior cesarean deliveries, and certified midwives or physicians as birth attendants.
