The safety of out-of-hospital births attended by midwives who are lice
nsed according to international standards has not been established in
the United States. To address this issue, outcomes of births attended
out of hospital by licensed midwives in Washington state were compared
with those attended by physicians and certified nurse-midwives in hos
pital and certified nurse-midwives out of hospital between 1981 and 19
90. Outcomes measured included low birthweight, low five-minute Apgar
scores, and neonatal and postneonatal mortality. Associations between
attendant and outcomes were measured using odds ratios to estimate rel
ative risks. Multivariate analysis using logistic regression controlle
d for confounding variables. Overall, births attended by licensed midw
ives out of hospital had a significantly lower risk for low birthweigh
t than those attended in hospital by certified nurse-midwives, but no
significant differences were found between licensed midwives and any o
f the comparison groups on any other outcomes measured. When the analy
sis was limited to low-risk women, certified nurse-midwives were no mo
re likely to deliver low-birthweight infants than were licensed midwiv
es, but births attended by physicians had a higher risk of low birthwe
ight. The results of this study indicate that in Washington state the
practice of licensed nonnurse-midwives, whose training meets standards
set by international professional organizations, may be as safe as th
at of physicians in hospital and certified nurse-midwives in and out o
f hospital.