In the largest and most in-depth study of its type, it was confirmed that nausea and morning sickness have a protective effect on a developing fetus. 

According to a 2016 study published in the journal of the American medical association, those women who experienced morning sickness/nausea during their pregnancy had a 75% lower risk of experiencing complications. According to the lead researcher Dr. Stephanie Hinkle from the NICHD 'nausea/morning sickness appears to be a sign of a healthy pregnancy and even has certain protective qualities'. These protective qualities were first identified several years ago by researchers from Cornell university. Their review showed that nausea and vomiting serve as a protective mechanism for the developing embryo to ensure minimal exposure to toxic chemicals and micro organisms that may be harmful. The message from this research is that pregnant women should listen to their intuition and avoid foods that don't appeal, regardless of the proposed health benefits.