Hyperemesis gravidarum: the severe form of pregnancy vomiting

Hyperemesis gravidarum is broadly defined as "intractable vomiting associated with a weight loss of more than 5% of pre-pregnancy weight, dehydration and electrolyte imbalances that may lead to hospitalisation"[1].

According to the Formal Expert Consensus of the French National College of Gynaecologists and Obstetricians: "Hyperemesis gravidarum is distinguished from nausea and vomiting of pregnancy by a weight loss ≥ 5% or signs of dehydration or a PUQE score ≥ 7 (Pregnancy Unique Quantification of Emesis and Nausea). Hospitalisation is recommended when at least one of the following criteria is present: weight loss ≥ 10%, one or more clinical signs of dehydration, PUQE score ≥ 13, hypokalaemia < 3.0 mmol/L, hyponatraemia < 120 mmol/L, elevated creatininaemia> 100 mmol/L or resistance to treatment." [26]

A blood test will be needed to assess nutritional needs in particular. 

Some pregnancy nausea, accompanied or not by vomiting, are reported by nearly 80% of pregnant women [2].

Hyperemesis gravidarum affects between 0.3% and 3% of pregnant women [3]. On average, symptoms appear approximately 5 to 6 weeks after the start of pregnancy. In 50% of women, nausea and vomiting resolve by week 14, and in 90% of women by week 22 [4]. However, in 10% of hyperemesis cases, they may persist throughout the entire pregnancy [5].

Hyperemesis can lead to hospitalisation and sick leave. It sometimes causes complications during pregnancy and adverse consequences for babies, such as low birth weight [6].

Different people may be at high risk of hyperemesis gravidarum [7]: 

• Women with a multiple pregnancy
• Women who suffer from nausea and vomiting outside of pregnancy due to the use of oestrogen-containing medicines
• Women with a history of migraines
• Research also suggests a higher risk of hyperemesis in women whose immediate family members, such as their mother or sister, have also experienced hyperemesis gravidarum [8].

A rise in human chorionic gonadotropin (hCG)

Levels of human chorionic gonadotropin (hCG) may be a contributing factor. They peak during the first trimester, which corresponds to the typical onset of hyperemesis symptoms. Research shows a correlation between higher hCG concentrations and hyperemesis [9]. 

Oestrogens 

Oestrogens may also contribute to nausea and vomiting during pregnancy. Oestradiol levels rise in early pregnancy and decline later on, which mirrors the typical pattern of nausea and vomiting during pregnancy. Furthermore, nausea and vomiting are known side effects of oestrogen-containing medications. The higher the oestrogen levels, the greater the incidence of vomiting [10].

Changes in the gastrointestinal system

The lower oesophageal sphincter relaxes during pregnancy due to rising levels of oestrogen and progesterone. This leads to an increased incidence of symptoms of acid reflux in pregnancy (GORD), and one of the symptoms of GORD is nausea [11]. However, further studies are needed to confirm or rule out the link between GORD and vomiting. 

Genetics 

An increased risk of hyperemesis gravidarum has been demonstrated in women whose family members have also experienced hyperemesis gravidarum. Two genes, GDF15 and IGFBP7, are potentially linked to the development of hyperemesis gravidarum [12]. A more recent study from 2023 supports the role of GDF15. 

In severe cases of hyperemesis, complications include vitamin deficiency, dehydration with electrolyte imbalance, and malnutrition with weight loss. Thiamine, or vitamin B1, is a water-soluble vitamin whose deficiency can manifest in the context of persistent vomiting, as in hyperemesis gravidarum. This deficiency can lead to a condition known as Wernicke's encephalopathy [13]. 

This can also lead to excessive saliva production, which can be uncomfortable for the mother. To find out more, see our article hypersalivation in pregnancy.

Ketosis (the accumulation of ketone bodies produced during the breakdown of fats [14]) is also commonly included as a consequence of hyperemesis gravidarum [15]. 

There are cases of secondary injuries caused by severe and frequent vomiting, including oesophageal rupture [16] and pneumothorax [17]. In addition, patients suffering from hyperemesis may present higher rates of depression and anxiety during pregnancy [18].

For the foetus, the main risks would be low birth weight, placental abruption and premature birth [27].

These potential long-term complications for the baby may include: insulin resistance, anxiety disorders, sleep disorders, attention deficit hyperactivity disorder, and autism spectrum disorder [27].

Recommendations from the Formal Expert Consensus of the French National College of Gynaecologists and Obstetricians

It is advisable to stop prenatal vitamins and iron supplementation without stopping folic acid supplementation. Diet and lifestyle will be adapted according to symptoms. Aromatherapy should not be used. If the PUQE score is < 6, and even in the absence of evidence of their benefit, ginger, pyridoxine (vitamin B6), acupuncture or electrostimulation may be used even in the absence of evidence of their benefit.

Vitamin B1 must be systematically administered in cases of hyperemesis gravidarum requiring parenteral rehydration, in order to prevent the onset of Gayet-Wernicke encephalopathy. [26]

Natural remedies

Non-pharmaceutical approaches to treating nausea and vomiting include herbs such as ginger and chamomile, acupuncture and massage. Furthermore, it has been shown that psychological support from family and the medical team reduces the symptoms of hyperemesis gravidarum [19]. 

Ginger infusion

Studies have shown that ingesting ginger reduced episodes of nausea and vomiting within one week compared to a placebo. 

You will easily find ginger infusion bags in shops. Alternatively, you can prepare your own infusion by pouring a cup of simmering water over one to two teaspoons of freshly grated ginger. Leave to infuse for around ten to fifteen minutes, strain, then enjoy!

A word of caution regarding pickled ginger, commonly found in Japanese cuisine, which usually contains artificial sweeteners such as aspartame — best avoided during pregnancy (and even afterwards!).

Something different to try: a ginger beer as an aperitif! It is an alcohol-free ginger fizzy drink. Ginger beer is so spicy that it gives the impression of drinking an alcoholic beverage — perfect for raising a glass with the future dad without feeling frustrated in front of his pint of beer!

Lemon

Although there is no specific study in the case of hyperemesis gravidarum, it has been shown that lemon may have effects in reducing nausea and vomiting during pregnancy [20].

However, lemon may not suit everyone. In naturopathy, people are grouped into two categories: sanguino-plethoric and neuro-arthritic types (which differ according to their relationship with heat/cold, their mood, their relationship with food, etc.). The bodies of these two types of people react differently in the presence of acids, and in the case of the neuro-arthritic type, the body is unable to neutralise the acids [21]. Lemon is therefore not recommended for these individuals. Consult a naturopath if you are unsure about your profile.

Mint or peppermint

Leave 1 teaspoon of dried mint to infuse for 5 minutes in a cup of boiling water. Strain. The menthol will invigorate you while having an antispasmodic effect on the intestines. Mint will then be your ideal ally in cases of nausea (think also of mint sweets, easy to carry with you!). 

Similarly, peppermint can aid digestion and calm the stomach, as it contains properties that dispel gas and relieve cramps [22]. 

Mint aromas alone can also help reduce nausea and vomiting [23].

Lemon balm infusion

Lemon balm has antispasmodic, digestive, anti-bloating, anti-reflux and relaxing properties!  

Place one teaspoon of flowering tops (aerial parts) in a bowl of boiling water and leave to infuse for around ten minutes. Drink 3 cups a day at the end of meals until symptoms improve. 

If you would like to find out more, have a look at our article pregnancy and digestive complaints.

Foods naturally rich in B6

Herbes de Provence with 1.58 mg/100g.

Nuts and seeds such as pistachios (1.41 mg/100g) and sunflower seeds (1.24 mg/100g).  

Meats: duck breast (0.98 mg/100g), turkey (0.81 mg/100g).

Fish such as salmon (1 mg/100g). 

Fruits and vegetables, for example dried apricots (0.51 mg/100g), banana (0.44 mg/100g), lentils (0.5 mg/100g).

Our pregnancy vitamins are all rich in vitamin B6. 

Bye bye nausea

The 100% organic pregnancy-compatible supplement, made with ginger and cardamom, which helps reduce nausea and vomiting.

To take as a duo with our pregnancy food supplement in powder form Bump powder, to help ensure you meet your nutritional needs. 

Acupressure may reduce symptoms

Acupressure is a non-invasive variant of acupuncture that involves applying constant pressure to specific points or areas. P6 acupressure (or the Neiguan point) is proposed for treating the symptoms of nausea and vomiting. The P6 point is located on the inner side of the forearm, near the wrist [24].

It is preferable to book an appointment with a specialist rather than giving yourself a massage alone. Certain acupressure points should not be stimulated during pregnancy. To find out more, see our article on pregnancy acupuncture.

A few tips to ease nausea

Furthermore, in addition to dietary changes, here are a few tips to help avoid nausea or improve symptoms [24]:

• Eat small, frequent meals
• Avoid spicy or fatty foods and drink regularly; eat crackers in the morning and upon waking
• Remember to rest 
• Ventilate your rooms and avoid staying in confined spaces.

Vitamin B6 at therapeutic dose

Vitamin B6, or pyridoxine, is commonly used as a first-line treatment for nausea and vomiting in pregnancy. Used alone, it is associated with a reduction in nausea but not in vomiting [25].

Antihistamines

Certain antihistamine-based treatments may have an effect on receptors and reduce symptoms of nausea and vomiting. However, studies are conflicting and further research is needed to validate or rule out the effects of these treatments. 

Dopamine antagonists

Dopamine antagonists (molecules that prevent dopamine from binding to its receptors), such as metoclopramide, stimulate the gastrointestinal tract and have proven effective in reducing vomiting. Metoclopramide can cause tardive dyskinesia, though this is rare in younger patients.

Phenothiazine treatments, such as promethazine, are dopamine receptor antagonists that act by suppressing the trigger zone responsible for stimulating vomiting [24]. 

Diclegis

Diclegis is a medication prescribed for nausea and vomiting associated with pregnancy. It is composed of pyridoxine (vitamin B6) and doxylamine. It has not been studied specifically for hyperemesis gravidarum, but according to current research, the effect of Diclegis in cases classified as "nausea and vomiting" of pregnancy is between 70 and 80% [13]. 

Diclegis is marketed in North American countries and not in France. In France, either doxylamine alone (Dornomyl) or equivalents to Diclegis containing doxylamine are available: Cariban or Xonvea.

Hospital management

In the most severe cases, hyperemesis gravidarum may lead to hospitalisation. In this case, the mother will be administered intravenous solutions containing primarily saline solution to rehydrate and vitamin B1 to prevent serious neurological complications.

Other possible interventions are detailed in the Formalised Expert Consensus of the French National College of Gynaecologists and Obstetricians [26]. A management algorithm is outlined on a case-by-case basis. 

If nausea and vomiting persist, if you notice weight loss, or if you see signs of dehydration, please seek medical advice promptly. Do not hesitate to carry out a nutritional assessment to ensure your nutritional needs are being met. 

Every woman is different, and every pregnancy is different too… Some remedies will work for some women's nausea, but not for others. Listen to yourself — you are your own best ally!

For more information and support, do not hesitate to visit the website of theHG association.

Please be cautious about taking medication during pregnancy. This advice does not replace the opinion of a healthcare professional or any ongoing medical treatment. 

Please do not self-supplement or use essential oils without guidance from a healthcare professional, doctor, pharmacist, or naturopath trained in aromatherapy.

It is also advisable to consult a naturopath for personalised guidance and tailored support.