Scientists Identify Cause of Morning Sickness, Potentially Ending Misery for Many

A hormone that triggers nausea and vomiting is produced abundantly by the fetal portion of the placenta, a study published Wednesday in the journal Nature showed. It is the leading cause in the U.S. of hospitalizations during the first half of pregnancy. For the Nature study, researchers built on work exploring a link between a hormone called GDF15 and hyperemesis gravidarum.