A new study finds that pregnancy is a time when men are at greater risk. In fact, their risk doubles if their partner is both HIV-infected and pregnant.
The results were presented at the International Microbicides Conference (M2010) in Pittsburgh, along with findings of a pivotal study that is the first to ask whether using a microbicide during pregnancy is safe for women and their babies.
While a number of studies have shown that during pregnancy women are at increased risk of acquiring HIV from an infected partner, a new study has found pregnancy is a time when men also are at greater risk ? double the risk, in fact. The study, which involved 3,321 couples in which one partner was HIV-infected and the other not, is the first to show that a man in a relationship with an HIV-positive woman has a greater chance of becoming infected while she is pregnant than when she is not.
Even after accounting for behavioral and other factors that usually contribute to HIV risk, the increased risk associated with pregnancy remained. Biological changes that occur during pregnancy may make women more infectious than they would be otherwise, explains Nelly Mugo, M.D., M.P.H., of the University of Nairobi & Kenyatta National Hospital in Nairobi and the University of Washington in Seattle, who presented results of the study on behalf of the Partners in Prevention HSV/HIV Transmission Study team. The study was conducted in Botswana, Kenya, Rwanda, South Africa, Tanzania, Uganda and Zambia.
The researchers followed for up to two years 1,085 couples in which the male was infected and 2,236 couples in which the female was infected to understand the different circumstances and determinants that may contribute to HIV risk. During this time, 823 pregnancies took place, which allowed the researchers to look more closely at the particular risk factors for HIV that occur during pregnancy and not. In their analysis, they found that pregnancy was associated with increased risk of both female-to-male and male-to-female HIV transmission. But for women with an HIV- infected partner, the study found that factors other than pregnancy also likely contributed to this increased risk, such as sexual behavior. In men, however, the link between pregnancy and HIV risk was much clearer, even after considering whether or not they had engaged in unprotected sex or were circumcised. Measures of viral load and CD4 counts of the infected partner also had no bearing. Increased female-to-male transmission of HIV during pregnancy may be due to physiological and immunological changes that occur with pregnancy, the authors conclude, but more research will be needed to confirm this hypothesis.
Source: Microbicides 2010, USA