Morning sickness, also called nausea and vomiting of pregnancy, is a common condition. It occurs in about 70% of pregnancies and usually starts around 6 weeks of pregnancy and lasts for weeks or months. Symptoms usually improve during the second trimester (weeks 13 to 27; the middle 3 months of pregnancy). To get some relief you can follow this tips To help relieve morning sickness: Choose foods carefully. ... Snack often. ... Drink plenty of fluids. ... Pay attention to nausea triggers. ... Breathe fresh air. ... Take care with prenatal vitamins. ... Rinse your mouth after vomiting.