12th World AIDS Conference
Pregnancy and HIV
Mother-to-child transmission of HIV (also known as perinatal or vertical transmission) has been covered at conferences large and small, and the 12th World AIDS Conference in Geneva was certainly no exception.
"State of the HAART" treatment for pregnant women was also addressed, and one abstract from Italy explored the largely neglected issue of HIV-positive men safely fathering children with HIV-negative women by artificial insemination.
Although not available in the United States, a process has been used in Italy and Germany to remove HIV from spermatozoa with impressive success. The chart below shows the clinical outcome of the treatment in Germany and Italy.
(Seroconversion in the infants of these mothers was not included in the abstract, but to date, there have been no reports of HIV-infected babies being born to HIV-negative mothers.)
Between 1991 and 1998, 40 couples who had contacted a project known as "Assisted Reproduction in HIV-Discordant Couples" opted to enroll in the study that investigated the impact of treatment, pregnancy and parenthood on couples' psychological and psychosocial situations and their perspectives on life.
Data showed a slight decrease in psychological strain and stress, an increase in social contacts and disclosure, and a much more optimistic outlook during treatment, pregnancy and parenthood. The study concluded that assisted reproduction with processed sperm can reduce the risk of infection of negative women in sero-discordant couples. The study also concluded that the possibility to fulfill the desire for parenthood enhances the perceived quality of life for these couples. Reproductive counseling and assistance should be part of the medical care of people infected with HIV.
Although there are no long-term data available regarding the use of HAART during pregnancy, potent three-drug "cocktails" are being recommended with increasing frequency.
Ideally, by treating the pregnant woman's HIV infection with "standard of care" (HAART), maternal viral load may by reduced to undetectable levels, thereby reducing the risk of transmission to the infant. Unlike the ACTG 076 regimen in which AZT was used alone, there is less risk of developing drug resistance, and future treatment options are preserved. (Because AZT has demonstrated a significant ability to reduce transmission when used without other antiretrovirals, it is recommended for use as a component of combination therapy during pregnancy.)
A Los Angeles study reported on 14 HIV-positive pregnant women taking Viramune/AZT and either ddI, 3TC or ddC (Abstract (463/12152). Although three of the women experienced rash and one developed AZT-induced anemia, the regimen was considered well tolerated. Overall the combination was also effective in decreasing viral load to fewer than 200 copies, although two of the women had a less favorable response.
Seven out of the eight newborns have tested negative for viral DNA (results were still pending for one). All of the babies had CD4 counts and other lab values within normal range and none had any abnormalities.
A smaller study in Massachusetts reported on the acceptance, tolerance, adherence and outcomes of five pregnant women on triple combination therapy that included the protease inhibitor Viracept, or nelfinavir (Abstract 463/12152). Four of the women were also taking AZT and 3TC and one was taking AZT and ddC. None of the women discontinued therapy due to side effects and all self-reported good adherence to their regimens.
At the time of the conference, there were data available on four of the women. All had achieved undetectable viral loads and increased CD4 counts. (Data on the infection status of newborns was not included in the abstract.) Conclusions from this study were that triple drug combinations including Viracept were well accepted and tolerated in pregnancy, and that women experienced the expected virologic and immunologic outcomes (Abstract 32419).
By way of contrast, it is important to note that in developing countries (where most new HIV infections occur), even AZT monotherapy was used in the 076 regimen, is prohibitively expensive and not an option. Controversial, placebo-controlled clinical trials of a shorter-course of orally administered AZT (for two weeks prior to delivery), omitting both intravenous AZT during delivery and administration of AZT to the newborn, have proven to be effective in reducing the incidence of perinatal transmission by 51 percent.
In the Thailand study, about 19 percent of babies whose mothers received placebo became HIV-infected versus 9.2 percent when the short course AZT was given. This necessary "standard of care" reflects the economic status of regions where treatment for HIV-infected individuals is still not accessible. A short course of AZT costs approximately $80 as compared to about $800 for the 076 regimen. Additionally, in March 1998, Glaxo Wellcome announced a program of "preferential public sector pricing" for AZT for the reduction of perinatal transmission, cutting the cost of the drug in developing countries by as much as 75 percent.
The effectiveness of third trimester drug intervention, such as short-course AZT, reinforces data suggesting that the birth process is implicated in perinatal transmission. Administration of drugs that cross the placental barrier (similar to the blood brain barrier) such as AZT and possibly nevirapine (Viramune) at the point of delivery have also shown to reduce transmission from mother to infant. Minimizing the newborn's exposure to maternal blood is also important.
An abstract from Southern California examined the comparative transmission rate to babies delivered vaginally, versus a procedure referred to as a "bloodless Cesarean section" in which the infant is not exposed to macroscopic (visible to the eye) blood or bodily fluid from the birth canal (Abstract 23274).
One hundred and eight women participated and ultimately, 14 babies (13 percent) were infected with HIV. When the study data were analyzed to exclude study participants who had taken AZT there was a significant difference in the rate of transmission between the two groups (BCS vs. vaginal). Only 6.3 percent of the babies delivered surgically became infected compared to 23.7 percent of the control group that delivered traditionally. Those numbers represent a 73.4 percent reduction in transmission risk for women not taking (or unable to take) AZT.
"In the absence of (AZT) usage," this study concluded, "these data show that 70 percent to 75 percent of the perinatal transmission occurs from exposure to maternal blood and bodily fluids at the time of birth. This information is important for women who are unable to take AZT or other antiretroviral agents."
The National Institutes of Health presented a study in which the goal was to evaluate the relationship between method of delivery and perinatal transmission (Abstract 23275).
Data regarding 10,729 mother-child pairs, with deliveries occurring between 1982 and 1996 were available to the researchers. The overall transmission rate was 14 percent. Four clearly defined methods of delivery were examined: Cesarean section before onset of labor/rupture of membranes (elective); Cesarean section (non-elective); vaginal delivery with forceps or suction (instrumented); and vaginal delivery (non-instrumented). This meta-analysis also incorporated data regarding drug therapies the women received, CD4 counts and other important factors.
It was concluded that there was a 20 percent decrease in risk of transmission with elective Cesarean section as compared to other modes of delivery.
This article was provided by AIDS Project Los Angeles. It is a part of the publication Positive Living.