C

Vaginal delivery does not lower – and can actually increase – the risk of mother-to-child HIV transmission compared with elective Caesarean section, antiretroviral prophylaxis and avoidance of breastfeeding, so it is not a preventive measure (Newell, 2003, PMID 12886799). In contrast, maternal and neonatal zidovudine prophylaxis (PACTG-076 regimen) and complete avoidance of breastfeeding are proven interventions that cut transmission to <2% (Stringer & Vermund, 1999, PMID 10526917).