Answer: In most situations, the pregnant woman with HIV does not require any additional monitoring to that needed for a nonpregnant patient. Certainly, if we’re starting the mother on antiretroviral therapy, we want to document an adequate response to therapy. We would check viral load 2-4 weeks after therapy initiation and then monthly until she has achieved undetectable viral load.¹ Once viral load is undetectable, we can check it every 3 months (Table 1). In particularly, for a pregnant woman on antiretroviral therapy, we do want to document viral load in her third trimester. This viral load will be important for managing her delivery. In general, an elective C-section is recommended for women with HIV RNA >1,000 copies/mL in the third trimester in order to decrease the risk of perinatal transmission; women with undetectable viral loads may consider a vaginal delivery. Overall, viral load does not need to be checked more frequently, particularly if it has responded predictably to therapy.

We also would follow CD4 cell count carefully, as we would for any patient with HIV. For a woman with a very low CD4 cell count, we need to think about prophylaxis for opportunistic infections.

In terms of monitoring fetal health and safety, most obstetricians will recommend a fetal ultrasound in the first trimester to confirm dates and monitor development based on gestational stage.¹ This initial ultrasound also helps confirm delivery date. Elective C-sections are usually performed at 38 weeks’ gestation; so, it’s important to know when that will be. In addition, some obstetricians will recommend an ultrasound in the second trimester, especially if the mother is on an antiretroviral regimen that isn’t as well documented in pregnancy. This allows us to get a look at the fetus and see if there are any heretofore unrecognized problems in terms of teratogenicity or malformations. It will also be important to conduct glucose screening between 24 and 28 weeks’ gestation or earlier if the mother has risk factors for hyperglycemia during pregnancy or has had gestational diabetes in previous pregnancies. Glucose screening is particularly important in women taking protease inhibitors, since we know there is an increased risk of insulin resistance with these agents.

There is some question about whether to change the dose of antiretroviral therapy during pregnancy. For example, in pharmacokinetic interaction studies of protease inhibitors, we have seen a decrease in plasma levels during the third trimester of pregnancy. The guidelines suggest monitoring drug levels and possibly adjusting dose. We have not seen an increased risk of virologic breakthrough or transmission with these decreases in plasma levels. In fact, plasma levels have been shown to rise dramatically after delivery. So, it's a question of whether you should routinely modulate the dose or increase the dose of the drug during the third trimester. We do know that there are a number of metabolic and pharmacokinetic changes associated with pregnancy that logically might lead to varying plasma levels of the drugs.

Back to top

Answer: If a woman comes in to labor and delivery and she hasn't had an HIV test, she should definitely have a rapid HIV test done. If the rapid test is positive, the recommendation is to start intravenous zidovudine for the mother.¹ We would send for a confirmatory test, but we need to react to the positive rapid test. We would counsel the mother, explain the benefits and risks, and obtain informed consent. We would also want to start the baby on oral zidovudine immediately after delivery and continue for 6 weeks. If the ELISA results are positive, we would continue the zidovudine. If the mother’s ELISA is negative, we can stop the zidovudine.

Now, the question of whether we should give more than zidovudine has been raised. There have been some studies in which laboring mothers received a single dose of nevirapine. The recommendations suggest that nevirapine could be added to zidovudine if the mother has a high viral load or evidence of advanced HIV disease, but we are not going to know her viral load based on the results of the rapid test.¹ The data are just not very compelling.

If single-dose nevirapine is administered, we would want to think about continuing the mother on zidovudine until the results of the confirmatory test are available. That would protect against the decreasing nevirapine levels and ensure that if she is, in fact, HIV-positive, she is not on monotherapy. However, there is no blanket recommendation to either give it or not to give it.

Back to top