It’s a boy! It’s a girl! It’s a mosaic embryo

Ever since the late 1970s, when in vitro fertilization first made the dream of childbirth come true for some previously infertile couples, doctors have tried to improve the technique’s efficiency. Still, only 20 to 30 percent of would-be parents undergoing in vitro fertilization (IVF) start a successful pregnancy during a single attempt. The procedure costs an average of $10,000 in the United States and puts couples on an emotional roller-coaster.