Are you or someone in your family in the early stage of pregnancy and experiencing nausea and vomiting? These symptoms are common during pregnancy, and it is completely normal to feel uncomfortable during this time. However, you should know that this sickness can become severe and lead to an abnormal state called hyperemesis gravidarum. This article will help you understand this condition and what you can do.

What is hyperemesis gravidarum? 

Nausea and vomiting in pregnancy are typically normal, particularly in the early stages. However, when they become severe and interfere with daily activities, it results in difficulty maintaining fluid and food intake. This condition is known as hyperemesis gravidarum (HG). It is generally less common than the typical morning sickness, affecting up to 3 in 100 pregnant assigned females at birth (AFAB).¹  

Hyperemesis gravidarum can result in weight loss and dehydration, leading to the presence of ketones in urine and/or blood. Ketones are chemicals produced by the liver when breaking down fat as an alternative energy source for the body. Ketonuria (ketones in urine) or ketonemia (ketones in blood) indicate that the body is not utilising carbohydrates from food as fuel, and is instead breaking down fat for energy.^2,3

Causes of hyperemesis gravidarum

You might be wondering why this condition only happens to some pregnant individuals. While the exact mechanism has not been established, evidence suggests it is multifactorial. The following factors contribute to hyperemesis gravidarum:

Hormonal aspects

During your first trimester of pregnancy, the placenta and corpus luteum will produce human chorionic gonadotropin (HCG) and progesterone. These hormones are related to the symptoms of hyperemesis gravidarum and are suggested to be the cause of it. The level of HCG correlates with the degree of hyperemesis gravidarum symptoms. Its levels peak around 10 weeks of gestation and this is when most people have severe nausea and vomiting.^4,5

Elevated oestrogen levels are another potential factor in HG. This association comes from observing nausea in individuals with high oestrogen levels, such as those using oral contraceptives or having obesity. Oestrogen may contribute by slowing down digestion and intestinal transit time, leading to nausea and vomiting.⁵

Genetic predisposition

Some evidence shows that if you have a family history of HG, you have the risk of experiencing it. The genes GDF15 and IDFBP7 may be correlated to hyperemesis gravidarum.^2,5

Digestion system changes

When you are pregnant, your lower esophageal sphincter (muscle valve in the oesophagus) will become more relaxed due to hormonal changes, especially oestrogen and progesterone. This increases the risk of developing gastroesophageal reflux disease (GERD) symptoms in pregnancy. Nausea is one of the most common symptoms associated with this condition.²

Other risk factors

• Having a child for the first time (primiparity)
• Multiple pregnancies (twins or more)
• Female foetus
• History of having hyperemesis gravidarum in the previous pregnancy⁶

Sign and symptoms

Although nausea and vomiting are often labelled as morning sickness, these symptoms can occur at any time of the day. In hyperemesis gravidarum, symptoms may persist until 20 weeks or even throughout the pregnancy, whereas in typical pregnancy sickness, symptoms typically resolve by 16 to 20 weeks. Signs and symptoms include:^2,7

• Severe and prolonged nausea and vomiting
• Food aversion leading to inadequate intake
• Weight loss of 5% or more of the weight before pregnancy
• Dehydration manifested by thirst, dizziness, decreased urine output or dark urine, strong-smelling urine, and extreme fatigue
• Other uncommon symptoms include rapid heartbeat, low blood pressure, confusion, or fainting

How is hyperemesis gravidarum diagnosed?

You will be asked about your symptoms and medical history before or during your current pregnancy.  A physical examination will then be conducted to assess if you have experienced excessive weight loss, which is a potential indicator of hyperemesis gravidarum. 

Additional tests may include blood tests to check for abnormalities such as electrolyte imbalances or the presence of ketones in your blood. Your urine will also be analysed to assess dehydration and detect ketones. Additionally, an ultrasound may be performed to visualise your foetus and rule out the possibility of abnormal growth of trophoblastic cells in the placenta, known as gestational trophoblastic disease (GTD), as it shares similar symptoms.²

Management and treatment

Treatment measures depend on your clinical condition and the severity of the symptoms. Generally, besides adjusting your lifestyle and diet, you will also need medication and may be admitted to the hospital if needed.

Diet approach

• Identify potential triggers for nausea and vomiting during pregnancy, which can vary among individuals
• High-fat foods may provoke symptoms in some individuals
• Opt for plain foods such as toast, crackers, biscuits, and potatoes Cold or room-temperature foods might be easier to keep down than hot meals
• Consider incorporating ginger tea into your diet to ease your nausea
• Avoid strong smells that may induce nausea
• Ensure you have adequate fluid intake to compensate for fluid loss due to vomiting

Medication and hospitalisation

Your healthcare provider may switch your prenatal supplementation to folic acid only and may suggest using acupressure wristbands. Initially, you will likely be prescribed vitamin B6 (pyridoxine) and doxylamine for nausea relief, followed by antihistamines and dopamine antagonists like dimenhydrinate if needed.

If symptoms persist despite initial medication, stronger options such as promethazine, meclizine, or ondansetron may be considered. These medications can be administered orally, via injection, or through IV fluid.

If dehydration is present or if oral fluid intake is insufficient, saline IV fluid may be provided to ensure hydration and adequate nutrition during hyperemesis gravidarum.

In refractory cases, intravenous or intramuscular chlorpromazine or corticosteroid may be used for symptom management.²

FAQs

How do you deal with extreme morning sickness?

• Try to avoid nausea-inducing triggers, such as strong smells or certain kinds of food
• Eat more plain foods like toast or plain biscuits
• Get sufficient rest 
• Eat cold food if hot food makes you feel sick
• Avoid overeating and eat in smaller portions more frequently. Make sure to eat enough carbohydrates 
• Drink plenty of fluids to prevent dehydration 
• Ginger drinks may help reduce the symptoms.⁸

Is hyperemesis gravidarum a severe form of morning sickness?

Yes, hyperemesis gravidarum is more persistent and severe than regular morning sickness. It can lead to weight loss, inadequate food and fluid intake, electrolyte imbalance, ketonuria, and other complications.

Will hyperemesis gravidarum harm my baby?

Usually, hyperemesis gravidarum doesn't harm your baby. However, if dehydration persists or if nausea and vomiting are severe, it could result in lower birth weight for the baby. It's crucial to seek medical attention if symptoms become severe, as it may indicate hyperemesis gravidarum.^1,9

When should you be hospitalised for hyperemesis gravidarum?

When your symptoms persist and you're unable to consume adequate nutrients and fluids, you may require IV fluid administration or a stomach tube for nutrition, potentially leading to hospital admission for further management.

The reasons for hospital admission can include:^1,10

• Dehydration
• Severe vomiting that results in the inability to keep fluid and oral medication down
• Rapid weight loss
• Abnormal blood test results
• The presence of certain medical conditions such as heart or kidney disease, diabetes, or others

Summary

Hyperemesis gravidarum is a condition characterised by severe and persistent nausea and vomiting during pregnancy, resulting in dehydration, weight loss, and inadequate nutrient intake. While it typically occurs in the first trimester, it can persist throughout pregnancy. Hormonal factors such as elevated levels of hCG, progesterone, and oestrogen, as well as a family history of the condition, can contribute to its development. 

Evaluation may show the presence of ketones in urine and blood, which indicate your body's use of fat breakdown as an energy source. Management involves dietary modifications and medication to help with the symptoms. In cases of dehydration or inability to meet nutrient needs due to symptoms, hospitalisation may be necessary for IV fluid administration and alternative medication options.