Same-sex procreation

In recent decades, a new possibility for LGBT parenting, same-sex procreation (where two women could have a daughter with equal genetic contributions from both women, or where two men could have a son or daughter with equal genetic contributions from both men), has become a possibility, through the creation of either female sperm or male eggs from the cells of adult women and men. With female sperm and male eggs, lesbian and gay couples wishing to become parents would not have to rely on a third party donor of sperm or egg.

The first significant development occurred in 1991, in a patent application filed in 1991 by U.Penn. scientists to fix male sperm by extracting some sperm, correcting a genetic defect in vitro, and injecting the sperm back into the male's testicles. While the vast majority of the patent application dealt with male sperm, one line suggested that the procedure would work with XX cells, i.e., cells from an adult woman to make female sperm.

In the two decades that followed, the idea of female sperm became more of a reality. In 1997, scientists partially confirmed such techniques by creating chicken female sperm in a similar manner. They did so by injecting blood stem cells from an adult female chicken into a male chicken's testicles. Some years later, other Japanese scientists created female offspring by combining the eggs of two adult mice, though using a procedure that would not be allowed for humans.

In 2008, a flurry of announcements revealed further developments with human same-sex reproduction, with a patent application filed by an American researcher specifically on methods for creating human female sperm using artificial or natural Y chromosomes and testicular transplantation. A UK-based group, in an interview, predicted they would be able to create human female sperm within five years. Another group at the Butantan Institute in Brazil is working on creating male eggs from embryonic stem cells, and if successful, from adult skin cells, though their current experiments are with mice. All of these developments and more are listed in Timelime of Research in Human Same-sex Procreation.