Which statement about the timing of HIV transmission is most accurate?

• A. Antenatal transmission is the most common
• B. At the time of delivery
• C. Postnatal transmission through breastfeeding is the only period
• D. Transmission occurs only in the first trimester

Answer: (B)

Transmissions from mother to child can occur before birth, during labor and delivery, or after birth through breastfeeding. The largest share happens around the time of delivery, when the newborn is exposed to maternal blood and secretions as they pass through the birth canal. Antiretroviral therapy that suppresses viral load greatly lowers this intrapartum risk, and breastfeeding transmits HIV mainly if viral load remains detectable. So, the timing that best fits the typical pattern is transmission at the time of delivery.