This March, Hayashi, [...] had another announcement: his lab had repeated the I.V.G. process in mice, but this time it had produced fertilized embryos whose egg cells had been developed using stem cells from male mice - “mice with 2 dads”, as the headline in Nature put it. Futurists have speculated about broader possibilities, such as an embryo formed with the DNA of four people instead of two, or even a so-called “unibaby,” the result of a person reproducing with herself.

Quote from New Yorker "The Future of Fertility"