A 28-year-old woman with HIV-1 infection (CD4 count 450 cells/µL, viral load 45,000 copies/mL) on a tenofovir + lamivudine + efavirenz regimen for 18 months presents with amenorrhea for 3 months and a positive urine pregnancy test. She has been adherent to therapy. What is the most appropriate management regarding her antiretroviral regimen?

Explanation

## Clinical Context A pregnant woman with HIV on NNRTI-based therapy requires urgent regimen modification. Efavirenz, while previously considered acceptable, is now contraindicated in pregnancy due to teratogenicity concerns and superior alternatives. ## Key Point: **Efavirenz is contraindicated in pregnancy.** Current WHO and Indian guidelines recommend switching to an integrase inhibitor (dolutegravir)-based regimen or a protease inhibitor-based regimen for pregnant women. ## Efavirenz Teratogenicity ### Mechanism of Concern - Neural tube defects reported in animal studies (CNS malformations) - Human data from West Africa showed potential association with neural tube defects - FDA Pregnancy Category D (evidence of fetal risk; benefits may warrant use in pregnant women despite potential risks) - Current recommendation: **avoid in first trimester and throughout pregnancy** ### High-Yield: **Efavirenz is contraindicated in pregnancy, especially first trimester.** Switch immediately upon confirmation of pregnancy. ## Preferred Regimens in Pregnancy | Regimen | Status | Notes | |---------|--------|-------| | Tenofovir + Lamivudine + Dolutegravir | **Preferred** | Superior efficacy, minimal teratogenicity data reassuring, rapid viral suppression | | Tenofovir + Lamivudine + Lopinavir/r | Alternative | Protease inhibitor-based; safe but higher pill burden, GI side effects | | Zidovudine + Lamivudine + Lopinavir/r | Alternative | Older regimen; used if INSTI contraindicated | | Abacavir-containing | Avoid | Requires HLA-B*5701 screening; not preferred | ## Why Dolutegravir in Pregnancy? 1. **Superior efficacy** — faster viral suppression critical for maternal health and PMTCT 2. **Minimal teratogenicity** — no neural tube defects reported; reassuring safety data 3. **Placental transfer** — adequate fetal exposure for PMTCT 4. **Maternal tolerability** — fewer GI side effects than protease inhibitors 5. **Rapid viral suppression** — achieves undetectable viral load faster, reducing transmission risk ## Clinical Pearl: **All pregnant women with HIV should achieve undetectable viral load (< 50 copies/mL) by delivery to prevent mother-to-child transmission (PMTCT).** Integrase inhibitors offer the fastest route to viral suppression. ## Warning: **Do NOT continue efavirenz in pregnancy.** Do NOT discontinue antiretrovirals — this increases maternal disease progression risk and vertical transmission risk. Adherence to therapy is critical. ## Mnemonic: **PINT = Pregnancy INTegrase inhibitor** — dolutegravir is the preferred choice for pregnant women with HIV. [cite:Harrison 21e Ch 197; WHO Consolidated Guidelines on HIV in Pregnancy 2021]