text: I am amazed by the amount of misinformation in the responses thus far.  Although statistics vary, current estimates are that between 15% and 35% of the time HIV will be perinatally passed from pregnant women to their children.\n\nThe rate of perinatal transmission among babies studied since 1986 by the NYC-based maternal transmission study is 28%, which follows the rule that not every exposure leads to HIV infection. There is some evidence that transmission is more likely if the woman is HIV symptomatic, but asymptomatic women can also pass the virus to their children.\n\nInfants born to HIV positive women will test HIV antibody positive at birth due to passive immunity - being born with some of their mother's antibodies. As infants develop their own immune systems (including antibodies) they replace the passive immunity antibodies with their own antibodies.\n\nThis process is usually completed by 8-10 months of age, but not later than 15 months. Most medical practitioners use 18 months as the cut-off point for a definitive antibody test result.\n\nBottom Line:\nThere is no way for a male to infect a fetus directly. However, every sexual encounter you have while attempting to impregnate a women increases her risk of contracting HIV from you. If she becomes infected then there is a chance 15-30% chance that she may transmit it to her fetus. Regardless, if you plan on having children, both you and your partner need to have serious discussions with experts in the field of HIV medicine.