HIV-positive mothers have a less than2% chance of infecting babies during childbirth if they’re taking HIV meds. What about positive men? Can they produce negative babies too?

After Larry Madeiros responded well to HAART in 1996 and it looked like he might live a long, healthy life, he and his HIV-negative wife, Carol, decided to have children. Having convinced a physician to take their case, the couple became one of the first in the U.S. to try a procedure called sperm washing. It removes HIV from a semen sample, leaving almost no risk of infecting mother or child.

In May 1998, the Madeiroses welcomed Ashley, who was born HIV negative. “It gave us a new sense of hope,” says Carol. A year later brother Taylor, also negative, was born. Since then, more than 3,800 negative babies have been conceived in the U.S. using the method.

As of 2007, there are no known cases of a woman having been infected through washed sperm. “I had a better chance of being hit by a bus [than getting infected with HIV],” says Carol of the procedure. However, many fertility clinics still won’t work with positive men, fearing a lawsuit should something go awry. Those that do rarely advertise, fearing they may scare away negative patrons. The Centers for Disease Control says it needs more safety evidence before endorsing the procedure. Delaware and California, meanwhile, ban positive men from donating sperm, period (though at press time, the California legislature was considering a bill that would let positive prospective dads hand over their sperm to a lab for washing).

“What patients are trying to do is complicated and we go through all the complications with them,” says Ann Kiessling, Phd, founder of the Bedford Research Foundation, in Somerville, Massachusetts. The group helps positive and discordant couples, straight and gay, get pregnant. (Even if both man and woman are positive, the man must wash the HIV from sperm to reduce the risk of reinfection.) Bedford also ships washed sperm to clinics that wouldn’t have accepted the unwashed variety from a positive person.

A sperm-washing candidate must demonstrate good parenting capacity—including good general health—before donating semen. Then the sperm, which is not believed to house HIV, is separated out. The sperm and semen are both tested. If the virus turns up, the sample is discarded and the procedure repeated. Once a negative sample is secured, the woman can use either artificial insemination, where multiple sperm are placed in the uterus using a cervical cup and tube, or injection (both of which cost $300 to $700), or in vitro fertilization (IVF) to inject a single sperm directly into an egg (this costs up to $15,000). Most insurance companies don’t cover any of these methods. Because only one sperm is used in IVF, it involves less risk than does artificial insemination—though no women are known to have been infected either way—and often improves chances of conception. Happy Father’s Day.