Two women with HIV have given birth to healthy baby boys after undergoing special drug therapy to prevent the infection from being passed on, their doctors said Wednesday.

Hideto Gomibuchi, of the International Medical Center of Japan, said the two cases prove that HIV-infected women can give birth without transmitting the virus to their children. Gomibuchi was speaking at a meeting of the Japanese Society of Fertility and Sterility in Tokyo.

The babies were born at the center. The mothers, both in their 30s, are married to men who are not infected with HIV.

The women underwent multiple drug therapy treatment at the center, and were artificially inseminated when their HIV levels had receded.

One of the women gave birth in November and the other in March. Both babies were delivered by Caesarean section, a procedure believed to reduce the risk of infection at birth.

Immediately after their births, the babies were given an anti-HIV medicine known as HIV syrup. Blood tests have confirmed that the boys are not infected with the virus.