Hyperemesis Gravidarum




Larissa A W Jansen, Kelly Nijsten, Jacqueline Limpens, Rik van Eekelen, Marjette H Koot, Iris J Grooten, Tessa J Roseboom, Rebecca C Painter

Hyperemesis gravidarum is associated with an increased risk of preterm birth, low birth weight, NICU admission and neonatal resuscitation.

The majority of women, up to 80%, experience nausea and vomiting during pregnancy. Women at the severe end of this clinical spectrum may be diagnosed with hyperemesis gravidarum (HG). The etiology of the disease is likely multifactorial, including genetic, endocrine and infectious.  Hyperemesis gravidarum can lead to dehydration, electrolyte disturbances and weight loss. Currently there is no cure available for hyperemesis gravidarum, patients receive symptomatic and supporting treatment.


What is hyperemesis gravidarum (HG)?

Hyperemesis gravidarum (HG) is a severe form of morning sickness. While at least 80% of pregnant women may experience the nausea and vomiting of morning sickness, sometimes these symptoms become much more aggravated than is typical—this is hyperemesis gravidarum.

For women who experience HG, symptoms tend to progress rapidly beginning around the 6th week of pregnancy. Symptoms usually abate by the 18th to 20th week of pregnancy. However, in as many as 22% of cases, symptoms may last until delivery.

Typical symptoms include:

  • Dehydration (signs of this are dry mouth, persistent thirst, minimal urine output, and/or rapid heart rate)
  • Rapid weight loss
  • Vomiting that causes dizziness or lightheadedness
  • Vomiting three or more times per day

In addition to these, other symptoms can include:

  • Bad taste in the mouth
  • Difficulty reading (from dehydration, which can cause changes to the eye)
  • Increased sensitivity to odors
  • Shivering

Women who experience this condition suffer not only physically but mentally. The stress and strain of being ill and potentially hospitalized have numerous physical and mental effects, including stress, anxiety, and depression.


Doctors diagnose hyperemesis gravidarum by taking a detailed patient history and doing a physical exam. This might include blood tests to rule out other possible causes for the nausea and vomiting. The doctor likely will check for signs of dehydration, and depending on how far along you are in pregnancy, may check the baby's heart rate. Sometimes a pelvic exam is also done.

Exactly how and why hyperemesis gravidarum develops is unclear., It is believed to be primarily caused by an overproduction of the hormone human chorionic gonadotropin (hCG), which is produced by the placenta. Rapidly increasing blood levels of hCG are seen in women with HG, and the onset of symptoms often parallels that rise.

Some other pregnancy hormones are also believed to be involved in causing HG:

Cortisol: This stress hormone rises during HG, but it's unclear if this is a cause of the condition or a result of the stressful nature of experiencing it.

Estrogen: Since estrogen can increase your olfactory (smell) sensitivity, it may increase nausea and vomiting.

Progesterone: This hormone relaxes smooth muscle, which can delay or halt peristalsis (the wave-like contractions that move food in the digestive tract), which may contribute to the severity of morning sickness symptoms.

Prostaglandins: Prostaglandins may suppress cortisol and progesterone, influencing the pattern of HG.


There are several different medicines available to treat nausea and vomiting. Your symptoms might not disappear completely, but the aim is for you to manage to eat and drink some food or water during the day without vomiting.

Some people find that multivitamins make them feel sick. It’s fine to stop pregnancy multivitamins if this helps, if possible, try to continue taking folate.

If you’ve had hyperemesis gravidarum, in future pregnancies it can help to start taking medicine for nausea and vomiting as early as possible.


Try to drink fluids so you don’t get dehydrated. It can help to sip on a drink containing sugar or electrolytes every 15 minutes, or suck on ice blocks or icypoles.

If you can’t keep food or fluids down, go to your local emergency department. You will need intravenous (IV) fluids, which may help improve nausea and vomiting, and can help keep up your levels of electrolytes.


Try to eat small amounts regularly. Eat any food that you can keep down, as long as it’s safe in pregnancy — don’t worry about eating healthy foods right now.

You might need to see a dietitian. If you have low vitamin levels, you may need supplements.

In extreme cases, if you’re unable to eat, you may need to be fed through a tube. This can cause complications and requires careful monitoring.

Other treatments may include:

  • antacids or other medicines to treat reflux
  • laxatives for constipation
  • medicines to reduce saliva production

Rinse your mouth out with water after vomiting, to protect your teeth from damage. If you can, add some baking soda to the water you rinse with.

Can hyperemesis gravidarum affect my baby?

If you have hyperemesis gravidarum, your placenta may not be working as it should. This can affect your baby. Your baby may be more likely to be small and to be born early.


The experience of HG can be particularly challenging emotionally because many women have the belief that pregnancy will be a joyous time in their lives—and this condition is unpleasant to say the least.

Thankfully, most cases of HG will subside by 20 weeks' gestation, although some pregnant women still experience this condition throughout their pregnancy. Coping primarily involves lifestyle modifications and the various treatments recommended by your doctor.

Strategies that some pregnant women with hyperemesis gravidarum find helpful include the following:

  • Avoiding a completely empty stomach
  • Avoiding activity right after eating
  • Avoiding foods and smells that trigger nausea
  • Avoiding spicy, fried, sweet, and high-fat foods
  • Choosing bland, low-fat, easy-to-digest foods, like crackers, bread, and bananas
  • Drinking lots of fluids (water is best and ice-cold may go down the easiest)
  • Eating multiple, small, snack-sized meals per day
  • Eating slowly
  • Getting enough rest
  • Placing a cool, damp washcloth on your forehead
  • Showering
  • Using relaxation techniques, such as acupuncture, acupressure, meditation, baths, and deep breathing

Useful Links

Hyperemesis Australia


Pregnancy Birth and Baby


COPE – Centre for Perinatal Excellence


Panda - Perinatal Mental Health


Confirmation Content

Disclaimer: This publication by Miracle Babies Foundation is intended solely for general education and assistance and it is it is not medical advice or a healthcare recommendation. It should not be used for the purpose of medical diagnosis or treatment for any individual condition. This publication has been developed by our Parent Advisory Team (all who are parents of premature and sick babies) and has been reviewed and approved by a Clinical Advisory Team. This publication is not a substitute for professional medical advice. Miracle Babies Foundation recommends that professional medical advice and services be sought out from a qualified healthcare provider familiar with your personal circumstances. To the extent permitted by law, Miracle Babies Foundation excludes and disclaims any liability of any kind (directly or indirectly arising) to any reader of this publication who acts or does not act in reliance wholly or partly on the content of this general publication. If you would like to provide any feedback on the information please email [email protected].