Unsettled questions trail IVF's success

摘要

Back in 2001, developmental biologist Richard Schultz stood before a meeting of reproductive clinicians in New York City to present some uncomfortable results. Adult mice that had developed in vitro as early embryos, he reported, showed subtle differences from controls, including poorer spatial memory. He thought that his audience of experts on human in vitro fertilization (IVF)-extracting and combining sperm and egg in a culture medium, then transferring the embryo back into the mother's uterus-would be interested. "I was naive, " he says.