What is the recommended regimen for pre-labor HIV (Human Immunodeficiency Virus) prophylaxis?

Pre-Labor HIV Prophylaxis Recommendations

For pregnant women with HIV infection, the recommended pre-labor prophylaxis regimen is HAART (highly active antiretroviral therapy) that ideally contains zidovudine, started after the first trimester and continued through labor with intravenous zidovudine during delivery.

Antiretroviral Regimen Selection Based on Clinical Scenario

For HIV-infected pregnant women who have not received prior therapy:

• HAART (ideally containing zidovudine) should be initiated after the first trimester 1
• Continue HAART regimen during the intrapartum period with zidovudine given as continuous infusion during labor 1
• Nevirapine should be used with caution in women with CD4 counts >250/mm³ due to risk of severe hepatic toxicity 1
• Elective cesarean delivery should be considered if plasma HIV RNA remains >1000 copies/mL at 34-36 weeks gestation 1

For HIV-infected women already on HAART who become pregnant:

• Continue current HAART regimen 1
• Discontinue drugs with teratogenic potential (e.g., efavirenz) or with known adverse potential for pregnant women (e.g., stavudine-didanosine combination) 1
• In general, if the woman requires treatment, antiretroviral drugs should not be stopped during the first trimester 1
• Continue HAART during intrapartum period with zidovudine given as continuous infusion during labor 1

Intrapartum Prophylaxis Options for Women with No Prior Therapy

For women who present in labor with no prior antiretroviral therapy, several effective regimens are available:

1. Intravenous zidovudine given as continuous infusion during labor 1
2. Single-dose nevirapine (200 mg) at onset of labor 1
3. Oral zidovudine and lamivudine during labor 1
4. Combination of intravenous zidovudine plus single-dose nevirapine 1

Infant Prophylaxis

• For infants born to mothers who received adequate antenatal antiretroviral therapy: zidovudine for 6 weeks 1, 2
• For infants born to mothers who received no antiretroviral therapy before or during labor: either single-dose nevirapine (2 mg/kg) at birth PLUS zidovudine for 6 weeks, or zidovudine alone for 6 weeks 1, 2

Important Clinical Considerations

• Zidovudine remains the mainstay of perinatal prevention efforts and should be included in antiretroviral regimens for pregnant women whenever possible 1
• The risk of vertical transmission is significantly reduced with appropriate antiretroviral prophylaxis, with transmission rates declining from 25.5% to 8.3% with zidovudine prophylaxis alone 1
• Elective cesarean delivery before onset of labor and membrane rupture can further reduce transmission risk by approximately 50% in women with HIV RNA >1000 copies/mL 1
• Maternal viral load is a critical factor in transmission risk - achieving viral suppression to <1000 copies/mL (ideally <50 copies/mL) significantly reduces transmission risk 3

Postpartum Considerations

• After delivery, evaluate the need for continued maternal therapy 1
• If therapy is discontinued after delivery and the regimen included drugs with long half-lives (such as NNRTIs like nevirapine), consider continuing the nucleoside analogue drugs for 3-7 days after stopping the NNRTI to reduce the risk of developing resistance 1
• Breastfeeding is not recommended for HIV-infected women in resource-rich settings like the United States 1

Potential Risks and Monitoring

• Monitor for potential adverse effects of antiretroviral therapy during pregnancy, including hyperglycemia, lactic acidosis, hepatotoxicity, and premature labor 4
• For women receiving nevirapine, closely monitor liver function, particularly in those with CD4 counts >250/mm³ 1
• Pharmacokinetic changes during pregnancy may necessitate dose adjustments for some antiretroviral medications 5, 6