Vomiting during pregnancy, sometimes preventing food being taken and causing acidosis. Morning sickness and vomiting occur in the first three months in 50 per cent of pregnancies. Nausea is experienced upon waking. After vomiting, the woman feels better remarkably quickly and is able to eat. As a rule the vomit consists only of gastric mucus and bile. Frequent meals, five or six a day, with large amounts of carbohydrates and only a little fat, often appear to help. A serious form of vomiting during pregnancy occurs if vomiting continues after three months and no fluid or food at all can be kept down. The woman grows thin and is in danger of dehydration. She should be admitted to hospital in order for the liquid deficiency to be made good. Removing the woman from her familiar surroundings often also has a positive effect. This supports the idea that psychological influences play a part in causing excessive vomiting during pregnancy.