What is the recommended treatment regimen for pregnant women with Human Immunodeficiency Virus (HIV)?

Recommended Treatment Regimen for Pregnant Women with HIV

For pregnant women with HIV, a zidovudine and lamivudine-based antiretroviral regimen is recommended over tenofovir and emtricitabine-based regimens to reduce the risk of adverse neonatal outcomes while maintaining effective viral suppression. 1

First-Line Treatment Recommendation

The optimal antiretroviral therapy (ART) for pregnant women with HIV should prioritize both maternal health and prevention of mother-to-child transmission while minimizing adverse outcomes. Based on the strongest evidence:

• Backbone regimen: Zidovudine (AZT) + Lamivudine (3TC)
• Third agent options:
  • Ritonavir-boosted protease inhibitors (except lopinavir/ritonavir)
  • Integrase strand transfer inhibitors
  • Non-nucleoside reverse transcriptase inhibitors (in appropriate clinical scenarios)

This recommendation is based on evidence showing that tenofovir/emtricitabine combinations, particularly when combined with lopinavir/ritonavir, are associated with higher rates of early neonatal death and preterm delivery before 34 weeks compared to zidovudine/lamivudine regimens 1.

Treatment Decision Algorithm

1. For women already on ART before pregnancy:

   • Continue current regimen if it contains zidovudine/lamivudine
   • If on tenofovir/emtricitabine, especially with lopinavir/ritonavir, consider switching to zidovudine/lamivudine
   • Discontinue drugs with teratogenic potential (e.g., efavirenz) in first trimester 1

2. For women newly diagnosed during pregnancy:

   • Initiate zidovudine/lamivudine-based regimen with appropriate third agent
   • Consider delaying initiation until after first trimester if possible, but benefits of early treatment often outweigh risks 1

3. For women with HIV RNA >1000 copies/mL:

   • Combination therapy with highly active antiretroviral therapy (HAART) is strongly recommended 1
   • Include zidovudine in the regimen whenever possible

Special Considerations

Clinical Scenarios Where Tenofovir/Emtricitabine May Be Preferred:

• Severe anemia (zidovudine can worsen anemia)
• Lamivudine-resistant hepatitis B
• Drug allergy or intolerance to zidovudine/lamivudine
• Lamivudine or zidovudine-resistant HIV
• Significant drug interactions with other essential medications
• High value placed on once-daily regimen 1

Pharmacokinetic Considerations

Pregnancy alters drug metabolism and may affect antiretroviral levels:

• Lopinavir concentrations are approximately 40% lower during second and third trimesters compared to postpartum 2
• Darunavir exposures are generally lower during pregnancy, with greater reductions seen with once-daily versus twice-daily dosing 3
• These changes may necessitate dose adjustments or more frequent monitoring during pregnancy

Intrapartum and Postpartum Management

• Continue ART regimen during labor and delivery
• Administer intravenous zidovudine during labor if HIV RNA remains ≥1000 copies/mL at 34-36 weeks gestation 1
• Consider elective cesarean delivery if plasma HIV RNA remains ≥1000 copies/mL at 34-36 weeks gestation 1
• For the infant: Zidovudine prophylaxis for 6 weeks 1
• After delivery: Continue maternal ART if indicated for maternal health; if not indicated, consider discontinuing therapy 1

Common Pitfalls to Avoid

1. Inadequate viral load monitoring: Viremic episodes occur frequently during pregnancy and postpartum, with up to 22% of women experiencing major viremic episodes after initial viral suppression 4

2. Subtherapeutic drug levels: Physiological changes in pregnancy can lead to reduced antiretroviral concentrations, particularly in the later stages, potentially compromising efficacy 5

3. Inappropriate discontinuation: When stopping nevirapine-containing regimens postpartum, continue the nucleoside backbone for 3-7 days after stopping nevirapine to reduce resistance risk 1

4. Overlooking hepatotoxicity risk: Use nevirapine with caution in women with CD4 counts >250/mm³ due to increased risk of severe hepatic toxicity 1

The goal of antiretroviral therapy during pregnancy is to achieve complete viral suppression while minimizing adverse effects for both mother and infant. With appropriate treatment, perinatal transmission rates can be reduced to less than 2% 6.