Why is it called 'morning sickness' if it can happen any time of day?
Nausea and vomiting are extremely common in the early stages of pregnancy, and they've earned the widely used nickname "morning sickness." But why exactly have we come to call these tummy-turning symptoms morning sickness ? It turns out that, while pregnancy-related nausea and vomiting can happen at any time of day, the symptoms often flare just after waking up. Scientists don't know exactly why, but in general, studies suggest that hormonal changes in early pregnancy may drive morning sickness, according to a 2016 review published in the International Journal of Reproduction, Contraception, Obstetrics and Gynecology . A person's levels of reproductive hormones surge in the first trimester. One hormone, called human chorionic gonadotropin (hCG), may be directly responsible for the queasiness tied to morning sickness, Dr. Clara Paik , a professor and vice-chair of the Department of Obstetrics and Gynecology at UC Davis Health, told Live Science by email. ...