Table 4

Combined intrapartum and neonatal mortality in studies of planned out of hospital births or low risk hospital births in North America (at least 500 births)

Type of studies and references	Location, period	No of births	Combined intrapartum and neonatal mortality (per 1000) ^*
Low risk out of hospital births attended by midwives:
Burnett et al¹¹	North Carolina, 1974-6	934	3.0^{^†}
Mehl et al¹²	United States, 1977	1146	3.5
Schramm et al¹³	Missouri, 1978-84	1770	2.8
Janssen et al¹⁴	Washington State, 1981-90	6944	1.7^{^†}
Sullivan and Beeman¹⁵	Arizona, 1983	1243	2.4
Tyson¹⁶	Canada, Toronto, 1983-8	1001	2.0^{^†}
Hinds et al¹⁷	Kentucky, 1985	575	3.5^{^†}
Durand¹⁸	Farm, Tennessee, 1972-92	1707	2.3
Rooks et al¹⁹	84 birth centres across United States, 1985-7	11 814	0.6
Anderson et al²⁰	90 home birth practices across United States, 1987-91	11 081	0.9
Pang et al²¹	Washington State, 1989-96	6133	2.0^{^†}
Schlenzka²²	California, 1989-90	3385	2.4
Murphy et al²³	United States, 1993-5	1350	2.5
Janssen et al²⁴	Canada, British Columbia, 1998-9	862	2.3
Johnson and Daviss³⁷	United States and Canada, 2000	5418	1.7
Low risk births attended by physicians or obstetricians in hospitals:
Neutra et al²⁵	One academic hospital in Boston (lowest risk women), 1969-75	12 055	0.5-1.1^{^†}
Amato²⁶	One community hospital, 1974-5	4144	3.^{^†}
Adams²⁷	15 hospitals	10 521	1.7
Rooks et al²⁸	National natality survey, 1980	2935	2.5^{^†}
Janssen et al¹⁴	Washington, 1981-90	23 596	1.7^{^†}
Leveno et al²⁹	One academic hospital in Dallas, 1982-5	14 618	1.0
Eden et al³⁰	Twelve hospitals Illinois, 1982-5	8135	1.9
Pang et al²¹	Washington State, 1989-96	10 593	0.7^†
Schlenzka²²	California 1989-90	806 402	1.9
Janssen et al²⁴	Canada, British Columbia, 1998-9	733	1.4

Table is presented for general comparison only. Direct comparison of relative mortality between individual studies is ill advised. as many rates are unstable because of small numbers of deaths, study designs may differ (retrospective versus prospective, assessment and definition of low risk, etc.), the ability to capture and extract late neonatal mortality differs between studies, and significant differences may exist in populations studied with respect to factors such as socioeconomic status, distribution of parity, and risk screening criteria used. For example, see the study by Schlenzka. Although the crude mortality for low risk babies weighing over 2500 g intended at home was 2.4 per 1000 and intended in hospital was 1.9 per 1000, when standard methods were employed to adjust for differences in risk profiles of the two groups (indirect standardisation and logistic regression), both methods showed slightly lower risk for intended home births.
* Excludes lethal congenital anomalies.
† Neonatal mortality only, intrapartum mortality unreported.