W. Andiman et al., The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1 - A meta-analysis of 15 prospective cohort studies, N ENG J MED, 340(13), 1999, pp. 977-987
General & Internal Medicine","Medical Research General Topics
Background To evaluate the relation between elective cesarean section and v
ertical transmission of human immunodeficiency virus type 1 (HIV-1), we per
formed a meta-analysis using data on individual patients from 15 prospectiv
e cohort studies.
Methods North American and European studies of at least 100 mother-child pa
irs were included in the meta-analysis. Uniform definitions of modes of del
ivery were used. Elective cesarean sections were defined as those performed
before onset of labor and rupture of membranes. Multivariate logistic-regr
ession analysis was used to adjust for other factors known to be associated
with vertical transmission.
Results The primary analysis included data on 8533 mother-child pairs. Afte
r adjustment for receipt of antiretroviral therapy, maternal stage of disea
se, and infant birth weight, the likelihood of vertical transmission of HIV
-1 was decreased by approximately 50 percent with elective cesarean section
, as compared with other modes of delivery (adjusted odds ratio, 0.43; 95 p
ercent confidence interval, 0.33 to 0.56). The results were similar when th
e study population was limited to those with rupture of membranes shortly b
efore delivery. The likelihood of transmission was reduced by approximately
87 percent with both elective cesarean section and receipt of antiretrovir
al therapy during the prenatal, intrapartum, and neonatal periods, as compa
red with other modes of delivery and the absence of therapy (adjusted odds
ratio, 0.13; 95 percent confidence interval, 0.09 to 0.19), Among mother-ch
ild pairs receiving antiretroviral therapy during the prenatal, intrapartum
, and neonatal periods, rates of vertical transmission were 2.0 percent amo
ng the 196 mothers who underwent elective cesarean section and 7.3 percent
among the 1255 mothers with other modes of delivery.
Conclusions The results of this meta-analysis suggest that elective cesarea
n section reduces the risk of transmission of HIV-1 from mother to child in
dependently of the effects of treatment with zidovudine. (N Engl J Med 1999
;340:977-87.) (C)1999, Massachusetts Medical Society.