What Is Hyperemesis Gravidarum and How Is It Treated?

Woman with hyperemesis gravidarum in pregnancy

Hyperemesis gravidarum is thought to affect 1 in 100 pregnant people.



Morning sickness is an unfortunate but common symptom of pregnancy where one experiences nausea and occasional vomiting. Despite the name, it can occur in the morning or at night and, for most people, this nauseous feeling lasts until the end of the first trimester.

Hyperemesis gravidarum, however, is an extreme form of morning sickness which causes a pregnant person to experience excessive nausea and vomiting multiple times throughout the day. Often it is so severe that one is unable to keep down fluids or food, putting them at risk of dehydration, malnutrition, and weight loss. Unlike typical morning sickness, most people with HG have symptoms that last well beyond the first 12-14 weeks, sometimes up to 20 weeks, while for others the constant vomiting and nausea occur for the entire duration of pregnancy.



There is still a lot that is unknown about hyperemesis gravidarum, particularly what causes it and why some pregnant people experience it but others don’t.

If you are carrying twins or multiples, had HG in a previous pregnancy, or if your mother or sister had it, you are more likely to have hyperemesis gravidarum.



As debilitating as HG is for a pregnant person, if treated and managed effectively the condition is unlikely to harm or affect your baby.

For some people, HG can cause them to lose weight during pregnancy which can increase the chances of their baby being born at a lower birth rate. Your LMC will monitor your baby’s growth if they are concerned about this.

Hyperemesis can put you at risk of dehydration or malnutrition. Call your midwife or doctor immediately if you do not pass urine for more than 8 hours or have very dark-coloured urine, are unable to keep food or fluids down for 24 hours, feel severely weak, dizzy or faint when standing up, have abdominal (tummy) pain, have a high temperature (fever) of 38°C or above, are vomiting blood, or have pain when passing urine or any blood in your urine.

  • Focus on fluids. Aim to drink small amounts frequently throughout the day as dehydration can often exacerbate symptoms. If you’re struggling to keep food down, try to consume more nourishing fluids like electrolyte drinks, diluted juice, smoothies, milk and flavoured water.
  • Choose to eat foods that you can tolerate. Preferences tend to vary from person to person but many pregnant people report preferring bland, dry foods like crackers, potato chips, and toast.
  • Identify your triggers and communicate them to your partner and family to ensure they are managed as best possible. For some, this can include certain foods, smells, noises, times of day, or tiredness.
  • Prioritise rest. Hyperemesis is incredibly exhausting. While you may have times where you feel slightly better, it may be tempting to ‘get things done’ but it’s important to only do tasks that are essential. Ask for help from your village for everything else.
  • If you’re struggling to take your prenatal supplements, like folic acid and iodine, or are finding that certain medications make your HG worse, discuss your concerns with your LMC or doctor to create a management plan.
  • Seeing a specialist pregnancy dietician can be beneficial for specific nutrition advice to your circumstances.
  • HG can not only be physically challenging but emotionally so too. If HG is affecting your mental health, reach out to your LMC, friends, and whānau. It’s important to tell them how it’s impacting you emotionally to ensure you are receiving the support you need to cope with the rest of your pregnancy.



If your symptoms of nausea and vomiting are severe and affecting your day-to-day life, there are treatment options available that your LMC or GP may deem suitable for you. There are many pregnancy-safe anti-nausea medications that can be tried; metoclopramide is one of the most commonly prescribed medicines but there is also cyclizine, prochlorperazine, ondansetron and steroids.

In circumstances of dehydration and/or malnutrition, you may be admitted to the hospital to protect your and your baby’s health. Here, you may be given fluids and/or anti-nausea medication via an intravenous drip until you are well enough to keep down fluids on your own. In extremely rare cases, some people require nutrients via an IV or nasogastric tube.

Follow Hyperemesis Awareness NZ on Instagram for stories and support from other warriors and survivors of HG.