In July 2006, scientist Pablo Barreiro and colleagues published “Reproduction Options for HIV-Serodiscordant Couples,” in which they recommended methods for human immunodeficiency virus, or HIV, serodiscordant couples to procreate. An HIV-serodiscordant couple is one in which one partner is HIV-positive, meaning they carry HIV, and the other is HIV-negative, meaning they do not carry the virus. HIV is a virus that can spread by sexual contact and it attacks the immune system, causing a person with the virus to have weakened responses to illnesses. Because HIV can transfer from a pregnant woman to a fetus, fetuses conceived in an HIV-serodiscordant relationship could also be HIV-positive. The article “Reproduction Options for HIV-Serodiscordant Couples” offers HIV-serodiscordant couples options on how to procreate without passing HIV on to each other or their offspring.