Delay Tx until second trimester in drug-naive women with HIV: transmission risk low in first trimester.(Obstetrics)

SAN FRANCISCO -- It may be counterproductive to put drug-naive HIV-positive women on antiretroviral drugs early in pregnancy, Dr. Deborah Cohen said at a meeting on HIV management sponsored by the University of California, San Francisco.

That's because there's a good chance that they'll attribute normal hyperemesis of pregnancy to the medication, and this incorrect association will affect their desire to take antiretrovirals for a long time to come, said Dr. Cohen of San Francisco General Hospital.

Although preventing transmission of HIV to the fetus is a laudable goal, the literature shows that about two-thirds of the transmission risk occurs during labor and delivery, and most of the rest of the risk occurs during the last 2 months of pregnancy. That means there's little risk associated with delaying the start of an antiretroviral regimen until the second trimester.

In choosing an antiretroviral regimen, consideration should be given not only to teratogenicity (see box), but also to delineating the reason that the patient is going on therapy.

The patient--and the physician--need to decide whether she's taking antiretrovirals for her own health and will be continuing them after pregnancy, or whether this is only a matter of chemoprophylaxis to prevent transmission.

"We will in fact put women on what would be considered a less potent regimen in pregnancy, because they're going to be on it for a short period of time," Dr. Cohen said.

The considerations are different if the woman had been taking antiretrovirals before pregnancy. In general it's best to continue the woman on whatever regimen she's on, assuming that it's not teratogenic and she's tolerating her medication ...