Diagnosis & Treatment

None of the information provided by Hyperemesis Australia is meant to suggest any medical course of action. Instead, the information is intended to inform and to raise awareness so that these issues can be discussed by/with qualified Health Care Professionals. The responsibility for any medical treatment rests with the prescriber. All of the following information is in line with the Society of Obstetric Medicine of Australia and New Zealand Guideline For Management Of Nausea And Vomiting Of Pregnancy And Hyperemesis Gravidarum (2019). It may be helpful to print this document out and take it with you to doctor’s appointments.

Addressing the complex nature of nausea and vomiting in pregnancy (NVP) and hyperemesis gravidarum (HG) requires a combination of medications taken together on a strict schedule. Each recommended line of treatment includes medications that target specific aspects of the condition, with antihistamines combating nausea, antiemetics addressing vomiting, and antacids targeting stomach acid and reflux. Layering these medications together gives the best chance at symptom control and increases the likelihood of successful management. 

The Society of Obstetric Medicine of Australia and New Zealand recommended treatment protocol is as follows:

  • Pyridoxine (Vitamin B6) 10-50mg orally four times daily

  • One of the following taken orally up to three times daily:

    • Doxylamine 6.25-25mg

    • Prochlorperazine 5mg

    • Promethazine 25mg

    • Metoclopramide 10mg

    • Ondansetron 4-8mg taken orally two to three times daily

    To avoid sedation and for prolonged use i.e. more than 5 days, use Ondansetron during the day

    Additional treatment:

    • H2 antagonist eg. Ranitidine 150-300mg orally twice daily

    • IV fluids 1-3 x per week as required

    • Ondansetron 4-8mg taken orally two to three times daily

    Nighttime dosing with one of the following:

    • Metoclopramide 10mg IV or orally (if tolerating orally)

    • Prochlorperazine 5-10mg IV or orally (if tolerating orally)

    • Doxylamine 12.5-50mg IV or orally (if tolerating orally)

    • Cyclizine 12.5-50mg IV or orally (if tolerating orally)

    Consider adding:

    • Prednisone: commence 40-50mg daily or hydrocortisone 100mg IV twice daily and wean Prednisone over 7-10 days to minimal effective dose. May need to continue until symptoms resolve

    Additional Treatment:

    • Cease H2 antagonist and substitute with a proton pump inhibitor twice daily eg. Esomeprazole or Rabeprazole 20mg

    • IV fluids 1-3 x per week as required. Add IV thiamine if poor oral intake or administering dextrose

Despite common misconceptions, there are many anti-nausea medications suitable for use during the first trimester of pregnancy. 

Early and swift intervention is critical as nausea and vomiting, even when they continue for the duration of pregnancy, tend to peak during the first trimester. Research shows that most of the medications used to treat NVP and HG demonstrate greater efficacy when introduced early and all recent treatment guidelines reflect this in their recommendations. 

Unfortunately, some healthcare providers hesitate to intervene until patients exhibit significant weight loss or dehydration and/or electrolyte imbalances necessitating intravenous (IV) fluids. However, this approach does not align with best practice standards and can negatively impact maternal and foetal well-being in the long run. HG can be effectively managed without requiring in-patient treatment if sufferers are given easy access to appropriate interventions, and neither weight loss nor dehydration should serve as prerequisites for diagnosis or treatment.

Regrettably, many healthcare providers lack awareness of contemporary treatment protocols for HG management. If you encounter reluctance to prescribe medication from your care team and wish to explore this option, please reach out to us for further guidance and information.

Most medications for nausea and vomiting lack specific licenses for use during pregnancy due to the exclusion of pregnant individuals from pharmaceutical drug trials. This status quo is unlikely to change, as pharmaceutical companies typically abstain from including pregnant participants in trials to mitigate potential legal liabilities arising. It's important to note that this lack of licensing does not imply harm, but rather a lack of definitive evidence regarding safety in pregnancy. Nonetheless, certain medications are widely considered safe for use during pregnancy, and their safety is evaluated through alternative means such as pre-pregnancy usage records.

Ditch the ketones

Your healthcare provider may suggest the need for a ketone test or ketone urinalysis to determine dehydration. This is not best practice and you are within your rights to refuse - there are other methods for assessing hydration levels and whether IV rehydration is required.

Using ketones as a diagnostic criterion for HG or NVP overlooks the multifaceted nature of these conditions and the wide variability in symptoms and presentation among affected individuals. 

HG and NVP are complex disorders and focusing solely on ketone levels fails to capture the full spectrum of symptoms and serves as an unnecessary barrier to treatment.

Dehydration can instead be determined by: 

  • Physical examination to assess for signs of dehydration, such as dry mucous membranes (dry mouth, cracked lips) and reduced skin turgor (skin that tents or remains elevated when pinched)

  • Monitoring fluid intake and output for adequate oral hydration or reduced urine output

  • A decrease in blood pressure or an increase in heart rate upon standing may indicate dehydration

Medication without the worry

If you're having trouble keeping down medication because you're vomiting a lot, or if you’re worried that attempting to swallow a tablet may trigger a vomiting episode, there are other ways to take medication that might work better.

You could try suppositories, which you put in your back passage or injections given by your doctor. And there are some medications, like Ondansetron, that come in forms that melt on your tongue, so you don't have to swallow them. These options can go a long way to ensuring the success of any treatment plan and we encourage you to discuss them with your care team. 

If you are currently breastfeeding or chestfeeding and suffering from NVP or HG the Australian Breastfeeding Association has information to help you find out what medication is safe to take.