July 8, 2002
Dr. Valeria Savasi from University of Milan presented the latest results from their sperm washing insemination program for HIV-discordant couples (in this case, the women are HIV negative and males are HIV positive). This is one of the more frequently asked questions on the women's forum at The Body. Dr. Savasi did not discuss other options such as artificial insemination by a donor or adoption.
Dr. Savasi quoted estimates that 50 percent of fertile couples conceive in six months when having at least two episodes of unprotected sexual intercourse per week. Obviously, having unprotected sex among an HIV-discordant couple could lead to transmission of HIV to the uninfected partner. Previous studies have noted that the risk of transmitting HIV via vaginal intercourse is dependent upon the amount of HIV in the semen as well as other female host factors. Mandelbrot and colleagues (Lancet 1997) previously reported four HIV seroconversions among 92 HIV-negative women who became pregnant by HIV-positive partners. Dr. Savasi made an excellent point that all couples should be screened first for infertility problems such as genital tract infections, sperm immobility or low counts, female genital disorders such as endometriosis, tubal dysfunction or anovulatory cycles.
The actual technique of sperm washing is relatively easy. The semen is collected and immediately processed in a percoll gradient and centrifuged. The sperm settle to the bottom. Previous studies have shown that it is the non-sperm cells that contain HIV. The sperm pellet is then washed and the motile sperm swim up against the gradient and are collected into two aliquots, one for insemination and one for HIV-RNA testing by nucleic acid sequence-based amplification (NSBA). If the sample reveals less than the lower limits of detection for HIV (less than 800 copies/ml), the other aliquot can be artificially inseminated when the woman is ovulating. Although the abstract text reports 449 intrauterine inseminations in 175 couples, Dr. Savasi stated that over 4,000 inseminations in over 1,500 couples have been done since their program began. She did not state what the pregnancy rate was but in the abstract, she reported 10 percent. Of note, there has been no transmission of HIV to the uninfected female partners. I believe this will be a more commonly employed technique over the next few years. I discussed this presentation with a few obstetric colleagues at the meeting who agreed that this methodology was relatively easy and inexpensive and is especially attractive if it results in the decreased transmission of HIV.