Summary: | Background: With the increasing prevalence of HIV in Canadian women of child
bearing age, there is an attendant risk for increased perinatal HIV transmission. Use of
combination antiretroviral therapy in the HIV positive pregnancy, coupled with AZT
during labour and for the infant can significantly decrease risk of perinatal HIV
transmission to less than five percent. There is a need to establish i f Canadian HIV
positive pregnant women are receiving this intervention, and i f this has lead to a decrease
in perinatal HIV transmission in the Canadian setting. It is also important to establish i f
use of these medications in the antepartum period has any negative consequences on the
developing fetus.
Methods: This study used data gathered both retrospectively and prospectively from the
Oak Tree Clinic, the provincial centre providing clinical care for HIV positive pregnant
women in British Columbia. Care that HIV positive maternal infant pairs received
between January 1994 and December 1999 was evaluated. Chi square tests were
conducted to compare event rates between cohorts, and odds ratios with confidence
intervals were conducted to provide a measure of the strength of association between two
variables. A p value of 0.05 was considered statistically significant, and all reported p
values are two sided.
Results: One hundred and forty five HIV positive pregnancies were evaluated at Oak
Tree Clinic. Ninety-nine HIV positive women gave birth to 116 infants. Sixty five
maternal infant pairs received some type of antiretroviral treatment during pregnancy.
Twenty four pairs received combination antiretroviral therapy, twelve received dual
therapy and twenty nine received AZT monotherapy. Eighteen infants contracted HIV,
for an overall transmission rate of 15.5%. There has been a significant increase in the use
of combination treatment in pregnancy since 1996 (38.3% vs 75%; OR 6.37; 95% CI 2.4
-17.1) and a reduction in the perinatal transmission rate in the same time period (25% vs
5.4%, OR 5.9; 95% CI 1.6-21.6). In this study, no specific treatment regimen was linked
consistently with any adverse effects in the pregnancy or in the infant.
Conclusion: In one Canadian province, there has been a significant increase in the use of
combination antiretroviral treatment for HIV positive maternal infant pairs. This has lead
to a reduction in the perinatal transmission of HIV. === Medicine, Faculty of === Population and Public Health (SPPH), School of === Graduate
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