Taking marijuana for the treatment of nausea and vomiting in pregnancy may cause brain problems in newborns as well as worsen the mother’s health, according to a study on Monday.

About 70 per cent of pregnancies experience morning sickness in pregnancy, known medically as hyperemesis gravidarum, and characterised by nausea and vomiting. In severe cases, it can prevent pregnant women from eating and drinking properly, leading to weight loss and dehydration.