From the Guidelines
Hyperemesis gravidarum is not directly diagnosed by ultrasound, but ultrasound is crucial in its management to rule out other conditions that may cause or exacerbate hyperemesis, such as multiple gestation or placental abnormalities, as stated in the practice guidance by the American Association for the Study of Liver Diseases 1. When evaluating a pregnant patient with severe nausea and vomiting, an ultrasound should be performed to confirm a viable intrauterine pregnancy and exclude other diagnoses.
Key Points in Management
- The management of hyperemesis includes hydration, correction of electrolyte abnormalities, thiamine supplementation to prevent Wernicke’s encephalopathy 1, and anti-emetic therapy with agents such as ondansetron, which has favorable pregnancy safety 1.
- Anti-emetic agents like metoclopramide and promethazine can also be considered, as mentioned in the guidance statements 1.
- Vitamin supplementation, especially thiamine 100mg daily, is essential to prevent Wernicke's encephalopathy.
- Patients should be monitored for weight loss, ketones in urine, and electrolyte imbalances, and hospitalization may be necessary for severe cases requiring IV fluids and electrolyte replacement.
- Hyperemesis typically improves by 16-20 weeks gestation but can persist throughout pregnancy in some cases, with a high recurrence rate in subsequent pregnancies 1.
From the Research
Hyperemesis on Ultrasound
- Hyperemesis gravidarum is a severe and potentially life-threatening condition affecting up to 1.5% of pregnancies, characterized by dehydration and ketonuria 2.
- The diagnosis and management of hyperemesis gravidarum involve supportive treatment with intravenous rehydration, antiemetics, and correction of vitamin deficiency to minimize complications 2.
- There are good safety data to support the use of antihistamines, phenothiazines, and metoclopramide in hyperemesis gravidarum, although trials of efficacy are lacking 2.
Treatment Options
- Ondansetron is an efficacious treatment used widely for both nausea and vomiting of pregnancy and hyperemesis gravidarum, with recent studies providing conflicting findings on its safety during pregnancy 3.
- A randomized controlled trial compared ondansetron with metoclopramide in the treatment of hyperemesis gravidarum, finding similar antiemetic and antinauseant effects, but a better overall profile with ondansetron regarding adverse effects 4.
- Subcutaneous medications, including metoclopramide and ondansetron, have been used to treat severe nausea and vomiting of pregnancy, with significant improvement in symptoms and reduced need for hospitalization 5.
Diagnosis and Assessment
- Assessment of nausea and vomiting in pregnancy requires an objective evaluation using a validated scoring system, such as the PUQE-24 score, as well as calculation of hydration and nutritional status 6.
- Ketonuria is not associated with either the diagnosis or severity of hyperemesis gravidarum, and further investigation, including biochemistry, is only required in severe cases 6.
- A pathway for assessment and management of nausea and vomiting in pregnancy and hyperemesis gravidarum in the emergency room is presented, based on the Society of Obstetric Medicine of Australia and New Zealand Guideline 6.