Management of severe pregnancy sickness and hyperemesis gravidarum

### What you need to know Nausea and vomiting in pregnancy (NVP) affects around 70% of pregnancies. It is mild for around 40% of women, moderate for 46%, and severe for 14%.1 Mild to moderate NVP usually resolves in the second trimester, with 90% of cases resolving by 20 weeks.2 It does not generally require treatment. By contrast, hyperemesis gravidarum (HG) is a complication of pregnancy rather than a normal part of it and occurs in around 1.5% of pregnancies.3 It is not unusual for HG to persist throughout pregnancy.45 The psychosocial burden of HG can be heavy for women and their families, but effective and holistic treatment may reduce this.67 Historically, the aetiology of HG was poorly understood and it was thought to be caused by endocrine, infectious, psychosocial, and hereditary factors.4 However, recent studies in twins showed that severity and duration of NVP are highly genetic.8 Family history of HG leads to a threefold increased chance of the condition occurring among offspring.9 A genome wide association study found that genetic variants of the growth and differentiation factor 15 protein (GDF15) and insulin like growth factor binding protein 7 (IGFBP7) genes were strongly associated with NVP and HG.10 In another study, women with severe NVP symptoms who were …