Excessive nausea and vomiting in pregnancy
You are asked to see a young woman in the emergency department who is in the first trimester of pregnancy. She has been vomiting non-stop for several days, and she feels extremely unwell. She is understandably concerned for her baby.
Nausea and vomiting are normal and well known features of early pregnancy. Evidence suggests that 50-90% of pregnant women experience them.1
Symptoms generally start around four to seven weeks of pregnancy and disappear by 16-20 weeks.2 For most women these symptoms, although unpleasant, are not a cause for concern. For 0.3-2% of women, however, vomiting becomes so severe it causes dehydration and ketonuria (ketones in the urine). This is called hyperemesis gravidarum, and it requires hospital treatment.3 The pathophysiology of hyperemesis gravidarum is poorly understood, although a history of hyperemesis gravidarum, multiple and molar pregnancy, non-smoking, non-Caucasian, and younger maternal age are associated.4 In extreme circumstances it can be severe