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Getting the latest healthcare news for you

We know "Undetectable = Untransmittable" for sexual HIV transmission — but does it hold for breastfeeding? Experts say it's one of the most critical unanswered questions in HIV prevention. A new editorial in The Lancet HIV calls for large-scale prospective studies to find out, while a real-world case highlights the risks of informal breast milk sharing.
The U = U (Undetectable = Untransmittable) campaign has transformed HIV prevention by confirming that people with an undetectable viral load cannot sexually transmit the virus. But a new editorial in The Lancet HIV from UCLA's Dr. Dvora Joseph Davey and colleagues argues that whether U = U extends to breastfeeding remains a critical — and largely unanswered — question. While antiretroviral therapy (ART) has slashed breastfeeding-related HIV transmission rates dramatically, a small residual risk may still exist, and current evidence isn't strong enough to say with certainty.
A separate CDC MMWR report underscored the stakes: a woman with HIV and a viral load of 119,000 copies/mL had been informally donating breast milk via social media before her diagnosis. Though all infants ultimately tested HIV-negative, the case highlights the dangers of unregulated milk sharing.
Key Takeaways:
Why it matters: Millions of women with HIV worldwide face infant feeding decisions with incomplete guidance. Answering whether U = U applies to breastfeeding could reshape global HIV prevention policy and empower mothers to make truly informed choices.