Increased fetal production of a hormone known as GDF-15 (growth differential factor 15) is linked with nausea and vomiting during pregnancy as well as with hyperemesis gravidarum, the severe version of morning sickness, according to a new study that confirmed previous evidence tying the hormone to these symptoms. Pregnant people who are more sensitive to GDF-15, which can bind to receptors in the brain, also were more likely to become nauseous and vomit.
