Many women will be hesitant, or even resistant, to taking medication while pregnant. While there are risks associated with many of the recommended medications, these need to be weighed against the risks of leaving her symptoms untreated.

Mild to moderate NVP can often be managed without the need for pharmacological intervention. In more severe cases, however, where symptoms are impacting a woman's ability to eat and/or drink and weight loss is occurring the need for treatment increases. While concerns around medication use in pregnancy are valid, failing to treat NVP or HG can do more harm to mother and child than any medication.

The treatments listed below are supported by the RCOG for use in pregnancy and have not been found to cause harm to the developing foetus. Increasingly, evidence is showing the potentially harmful effects of malnutrition and dehydration during pregnancy, including the first trimester. Malnutrition in early pregnancy has been found to have lifelong cardiometabolic consequences for the offspring. Not treating a woman effectively enough to ensure she is able to eat and drink is more risky than leaving her untreated.

Additionally, the physical and psychological effects of profound and prolonged nausea and/or vomiting on the mother should not be underestimated and quality of life should be a factor in decision making about treatments. A recent systematic review of qualitative evidence found that even moderate NVP could have a serious detrimental effect on women's lives and mental health.

Mild to moderate NVP or HG

  • Doxylamine 12.5-25 mg PO NOCTE OR Prochlorperazine 25mg PR NOCTE

(first dose 20-30 minutes before getting out of bed, second dose 1-2pm)


  • Metoclopramide 10mg PO BD

(first dose 20-30 minutes before getting out of bed, second dose 1-2pm)


  • Ranitidine 150mg PO BD

Severe HG

Treatment in Day Unit, ED or inpatient

  1. IV fluid replacement with normal saline 1-2L over 1-4 hours

  2. Antiemetics (try sequentially)

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

    • Prochlorperazine 10mg IM or 25mg PR (if tolerating orally)

    • Ondansetron 4mg IV or PO (if tolerating orally)

  3. IV potassium, magnesium, thiamine

  4. Ranitidine 50mg IV or 150mg PO (if tolerating orally)

Treatment upon discharge

  1. Continue antiemetics depending on response

    • Metoclopramide 10mg PO BD OR Ondansetron 4mg PO BD

(first dose 20-30 minutes before getting out of bed, second dose 1-2pm)


    • Doxylamine 12.5-25 mg PO NOCTE OR Prochlorperazine 25mg PR NOCTE

  • Add regular therapy for gastroesophageal reflux

    • Ranitidine 150mg PO BD

    • Rabeprazole 20mg PO OD-BD

  • Continue antiemetics, acid suppression and IV fluids as required

These dosages are the absolute minimum that should be administered. If these are not enough to hold a patient we recommend increasing to the maximum daily amount - and giving prescriptions that will allow for these amounts to be taken daily as instructed over a long period.

The best way of treating Hyperemesis is to layer medications together, if a patient is not responding, adding another layer to her medications will help control another symptom. NVP and HG are multifaceted conditions that require the management of a number of symptomatic responses. Since antihistamines control nausea, antiemetics vomiting and antacids, like Ranitidine, stomach acid and reflux all are required to fully control the illness. Layering them allows for all bases to be covered and ensures a greater chance of successfully stabilising the patient. If treatment is started early enough then further treatment may not be needed. In second and subsequent pregnancies first line treatment should be used as a prophylactic (taken before conception to prevent the onset of symptoms), pre-empting the severity experienced in previous pregnancies. It is most effective when used as early as possible.


If all other pharmacological interventions have failed to adequately manage a woman’s symptoms it may be necessary to introduce corticosteroids. There is still concern that administration of corticosteroids prior to ten weeks gestation may increase the risk of oral clefts. Although cohort studies using corticosteroids for treatment of NVP have been enthusiastic, RCTs have been less convincing. If steroids are used, usual commencement is with either hydrocortisone 100mg IV bd or Prednisone 50mg daily, reducing to the lowest dose that controls symptoms (usually 5–10mg/day) over 7–10 days. This dose may need to be maintained until the natural resolution of NVP.

Medication recommendations from A/Prof Sandra Lowe (2012) It’s not just morning sickness O&G Magazine, Vol. 14 No 3 | Spring 2012