0.5 percent: The rate of mother-to-child transmission (MTCT) among all HIV-
positive mothers in Denmark since 2000. The percentage of babies born positive fell to 0 among moms who did these things: received HIV meds during pregnancy and labor, gave their newborns preventive HIV meds, and refrained from breast-feeding their babies.

6.3 percent: The rate of MTCT among HIV-positive mothers—many of whom were not on treatment or had begun meds late in pregnancy—in St. Petersburg, Russia, between 1998 and 2002.

Among both the Danish and the Russian mothers, more HIV-positive babies were born to women who delayed starting HIV treatment.