What are the other Names for this Condition? (Also known as/Synonyms)

• Intractable Nausea and Vomiting of Pregnancy
• Pernicious Vomiting of Pregnancy
• Severe Nausea and Vomiting of Pregnancy

What is Hyperemesis Gravidarum? (Definition/Background Information)

• Hyperemesis Gravidarum is a very severe form of nausea and vomiting that occurs during pregnancy. It is associated with severe nausea and vomiting, weight loss, and dehydration
• In a normal pregnant woman nausea and vomiting usually begins in the 4th week of pregnancy and ceases by the 16th week. This is commonly referred to as morning sickness. The nausea and vomiting experienced is usually mild and self-limiting
• However, if it is prolonged and severe, it is known as Hyperemesis Gravidarum. The condition normally begins during the 4th or 5th week of pregnancy and subsides at around 20 weeks
• At the time of onset of the signs and symptoms, and during the course of the condition, the affected mother may experience dehydration, weight loss, muscle weakness, and sometimes, esophageal tears or rupture (from severe vomiting) 
• Hyperemesis Gravidarum is the most common cause for hospitalization during the first trimester of pregnancy. Despite this, in a majority of cases, the mother is not known to experience any significant long-term complications as a result of the condition
• There is no clearly established cause as to why the condition develops in some pregnant women. However, women who have experienced it during their first pregnancy, have a higher risk for developing Hyperemesis Gravidarum in subsequent pregnancies 
• Hyperemesis Gravidarum can be treated by conservative measures, such as lifestyle and dietary modifications, or by administration of antiemetics after 12-16 weeks of pregnancy (so as to avoid the fetus from being affected)
• If left untreated, the condition can be detrimental to the health of the fetus. It may cause fetal growth restriction leading to delivery of small for age babies (babies that are smaller than they should be for that duration of pregnancy), among other complications

Who gets Hyperemesis Gravidarum? (Sex and Age Distribution)

• Hyperemesis Gravidarum is a relatively rare condition that occurs in less than 2% of all pregnancies
• Worldwide, pregnant women of all races and ethnic groups are prone to Morning Sickness. However, some reports inform that it is more common in the western nations of the world

What are the Risk Factors for Hyperemesis Gravidarum? (Predisposing Factors)

Presently, there are no clearly identified risk factors for Hyperemesis Gravidarum. However, the following are known to predispose some women to the condition:

• Women with a previous history of Hyperemesis Gravidarum (in past pregnancies)
• Family history of Hyperemesis Gravidarum
• First-time mothers may be at a higher risk
• Presence of certain fetal abnormalities such as trisomy 21, hydrops fetalis, etc.
• Molar pregnancies
• Gastrointestinal disorders
• Obese women
• History of eating disorders 

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hyperemesis Gravidarum? (Etiology)

The exact cause of Hyperemesis Gravidarum is currently unknown. However, it is thought to be the result of certain endocrine abnormalities and motility disorders. 

• The main hormone that is believed to be associated with Hyperemesis Gravidarum is beta hCG (human chorionic gonadotropin), a hormone produced during pregnancy
• An excess of beta hCG, seen in certain mothers, is speculated to be the reason for the development of Hyperemesis Gravidarum
• Beta hCG is elevated in certain conditions associated with pregnancy, such as Down syndrome, and molar pregnancies
• Certain motility disorders, such as gastroesophageal reflux disease (GERD), is often linked to Hyperemesis Gravidarum. GERD is thought to be triggered by excess progesterone present during pregnancy, or sometimes due to compression of the gastrointestinal tract by the enlarging uterus

What are the Signs and Symptoms of Hyperemesis Gravidarum?

The signs of symptoms of Hyperemesis Gravidarum vary according to the severity of the condition and may include:

• Severe nausea and excessive vomiting 
• Dehydration that may be severe
• Dizziness
• Excessive salivation
• In severe cases, pregnant women may present with muscle-wasting, altered mental status, and significant weight loss (loss of over 3 kg of body weight) 

The signs and symptoms of Hyperemesis Gravidarum usually start around the 4th or 5th week of pregnancy and generally subside by the 20th week.

How is Hyperemesis Gravidarum Diagnosed?

Hyperemesis Gravidarum is mainly diagnosed clinically (based on the symptoms that the expectant mother experiences), although other exams and diagnostic tests may be sometimes necessary. 

These exams and diagnostic tests may include:

• Complete physical exam and evaluation of medical history
• Examination of blood samples to determine serum blood, urea, and creatinine levels, which are usually elevated in Hyperemesis Gravidarum
• Blood tests may also help assess for other signs of dehydration (such as elevated hematocrit or hemoglobin)
• Examination of urine samples to detect the presence of ketones
• Ultrasound scan of abdomen and pelvis, to rule out other conditions such as gallbladder disease, hydatidiform mole, and liver disease

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hyperemesis Gravidarum?

Hyperemesis Gravidarum can cause complications in both the mother as well as the fetus.

Fetal complications may include:

• Lower weight at birth
• Small for age babies (babies born smaller than they should be for that duration of pregnancy)
• Birth of baby before 37 weeks of pregnancy (preterm birth)

Maternal complications may include:

• Severe dehydration
• Electrolyte imbalance and ketones in urine (ketonuria)
• Malnutrition
• The condition can cause changes in mental status due to development of Wernicke’s encephalopathy
• Severe muscle wasting and weakness
• Esophageal rupture or perforations may occur due to frequent retching during episodes of severe vomiting

How is Hyperemesis Gravidarum Treated?

A treatment plan for Hyperemesis Gravidarum is usually formulated based on the severity of the symptoms. A conservative management of the condition is usually preferred for mild cases. These include:

Dietary modifications:

• Consuming bland foods that are low in fats
• Avoiding large meals, and instead, consuming multiple, small, spaced-out meals 
• Consuming foods rich in protein
• Increased consumption of ginger, as it is found to be helpful in controlling nausea and vomiting associated with Hyperemesis Gravidarum
• Emotional support may be necessary to reassure the pregnant woman and help alleviate emotional stress

Treating any underlying conditions, such as obesity or eating disorders, which may be contributing to the condition is important.

Therapeutic/medicinal management:

• Administration of antiemetic medications and/or promotility agents such as promethazine and metoclopramide
• Administration of pyridoxine (vitamin B6) and thiamine (vitamin B1) are also commonly used treatment modalities
• In case of dehydration, rehydration therapy may be undertaken

Patients who do not respond to conservative or therapeutic measures and show significant weight loss may require nutritional support. However, it is reported that only less than 1% of those affected generally require hospitalization.

How can Hyperemesis Gravidarum be Prevented?

Currently, there are no specific measures available to prevent Hyperemesis Gravidarum.

• Individuals with a previous history of the condition, or presenting any associated risk factors, are encouraged to follow dietary and/or lifestyle modifications, in order to reduce the severity of the condition
• Complications of the condition can be prevented by early treatment and close monitoring of pregnancy

What is the Prognosis of Hyperemesis Gravidarum? (Outcomes/Resolutions)

In many cases, Hyperemesis Gravidarum resolves by the 20th week of pregnancy. It is not generally known to cause any significant long-term effects in the mother or baby.

• Only less than 3% of the affected women show persistence of symptoms beyond 20 weeks of pregnancy
• With adequate treatment, the prognosis of Hyperemesis Gravidarum is usually good
• Some mothers have shown persistence of neurological issues (from severe dehydration) and decreased likelihood to attempt another pregnancy due to the emotional stress caused by Hyperemesis Gravidarum during the course of the pregnancy

When the condition is left untreated, or remains unresponsive to treatment, the pregnancy outcomes may be unfavorable.

Additional and Relevant Useful Information for Hyperemesis Gravidarum:

Daily intake of a multivitamin with folic acid (vitamin B6) at least one month prior to conception is found to decrease severity and frequency of nausea and vomiting during pregnancy.