With a new technology called in vitro gametogenesis (IVG), scientists produced an egg from a male mouse, leading to two male mice having offspring. In mice. IVG could be a game changer for women and men dealing with infertility, women of advanced maternal age, and same-sex couples.

Last March, 4,000 frozen eggs and embryos were lost at University Hospitals Fertility Center in Cleveland when the temperature in cryogenic tanks spiked due to human error. Officials at University...