Hyperemesis Gravidarum: Why Occurs and When to Seek Help

Morning sickness, characterized by nausea and vomiting, affects nearly 70% of pregnant women worldwide. Typically, women experience symptoms in the morning, and they subside after the first trimester. But not always. If nausea and vomiting persist throughout the day, impeding eating and drinking adequately, it is considered hyperemesis gravidarum. This condition is dangerous for both the woman and the baby inside, prompting researchers at the University of Amsterdam to analyze dozens of studies to understand the causes, diagnostic parameters, and methods of therapy for this disorder.

Their review was published in the Canadian Medical Association Journal.

About Hyperemesis Gravidarum

This diagnosis is made when nausea and/or vomiting are so severe that a woman cannot eat and drink adequately, leading to weight loss and dehydration.

Researchers examined randomized clinical trials and systematic reviews related to the pathophysiology, diagnosis, impact, and treatment of hyperemesis gravidarum.

Causes of Hyperemesis

The cause of hyperemesis gravidarum remains incompletely understood. The study authors include the following risk factors:

• Pregnancy at a young age;
• Singleton pregnancy with a female fetus;
• Multiple pregnancies, especially with male fetuses;
• Molar pregnancy – intrauterine fetal demise – including in the patient’s medical history;
• Thyroid and parathyroid disorders;
• Gastrointestinal disorders;
• Psychiatric disorders;
• Type 1 diabetes;
• High cholesterol levels in the blood;
• History of hyperemesis gravidarum.

Researchers note that foremost, it is crucial to rule out molar pregnancy and multiple pregnancies when suspecting hyperemesis.

Diagnosis

Since 1968, the diagnosis has been established between the 4th and 8th weeks of pregnancy with the presence of more than three episodes of vomiting per day. Additionally, the woman experienced weight loss, electrolyte imbalance, and ketonuria – ketone bodies in the urine, which are products of fat and protein oxidation in the body. However, more recent studies have proven that the presence of ketonuria is not mandatory for diagnosis.

A more modern way to indicate the disorder is called the Windsor definition. The diagnosis is established based on the following criteria:

• Nausea and at least one severe vomiting episode per day;
• Inability to drink and eat normally;
• Inability to perform routine tasks;
• Occurring within the first 16 weeks of pregnancy.

Complications

In addition to deteriorating quality of life, hyperemesis can lead to complications, sometimes even fatal for both the mother and/or the child. Due to constant vomiting, the woman fails to obtain necessary vitamins, including thiamine (vitamin B1). This can cause a rare but grave condition – Wernicke’s encephalopathy, resulting in the death of the child in 50% of cases and the mother in 5%. Another threatening complication is antenatal and postnatal venous thromboembolism, as well as preeclampsia.

Among other complications confirmed by research, authors found depression and even post-traumatic stress disorder (PTSD). Sometimes this leads women to terminate desired pregnancies and fear becoming pregnant again. Fetuses also suffer in the womb, with a higher risk of developing psychological disorders in the future. Additionally, there was a higher likelihood of placental abruption, preterm birth, low birth weight, and the need for neonatal resuscitation after birth.

Treatment of Hyperemesis

The authors of the review note: there is a lack of research on the therapy of hyperemesis gravidarum. The problem mostly lies in the fact that not all medications are safe during pregnancy. Therefore, treatment involves two steps: stopping vomiting and supporting the intake of nutrients into the woman’s body. Of course, self-prescribing medications is highly dangerous, so if the symptoms described above are observed, immediate medical attention should be sought from one’s healthcare provider.