Nausea and vomiting in pregnancy usually begins at 4-7 weeks of gestation and resolves by 16 weeks of gestation. 75-80% of pregnancies with nausea and vomiting can seriously affect the quality of life and should be managed appropriately. 0.5%-2% of pregnancies with hyperemesis gravidarum are diagnosed on the following bases: persistent vomiting, large amounts of urinary ketone bodies and weight loss ≥5%. The majority of cases improve after treatment and the pregnancy can be continued. If the following conditions are life-threatening, termination of pregnancy should be considered: 1) persistent jaundice, 2) persistent proteinuria, 3) elevated body temperature above 38°C, 4) tachycardia with heart rate ≥120 beats/min.