The safety of tenofovir for pregnancy is derived from data on pregnancies in women with AIDS, in which approximately 2,400 pregnant women with AIDS taking tenofovir gave birth to babies with birth defects (malformations) at a rate of 2.3-2.4%, while the overall population of women also had a 2.72% rate of birth defects in their babies, and thus tenofovir is considered safe for women with no effect on their pregnancies. It is important to emphasize that tenofovir being safe for childbirth is not the same as being completely risk-free, as there is a 2.7% risk of birth defects inherent in the births of women in the overall society.