From the Guidelines
Hyperemesis gravidarum is caused by a combination of factors, including elevated levels of human chorionic gonadotropin and estrogen, as well as other hormonal and genetic factors, as noted in the most recent study 1. The exact mechanism of hyperemesis gravidarum is not fully understood, but it is associated with various risk factors, including:
- Hyperthyroid disorders
- Previous molar pregnancy
- Psychiatric illness
- Pre-existing conditions, such as diabetes mellitus and asthma
- Singleton female pregnancies
- Pregnancies with multiple male fetuses As reported in the study 1, higher growth or differentiation factor-15 levels in maternal blood have also been found to be associated with vomiting in pregnancy and hyperemesis gravidarum. It is essential to note that hyperemesis gravidarum can lead to dehydration, weight loss of >5% of prepregnancy weight, and electrolyte imbalances, affecting 0.3%–2% of pregnant persons, as stated in the study 1. The evaluation of hyperemesis gravidarum involves comprehensive history taking and physical examination, focusing on signs of dehydration, as mentioned in the study 1. While the cause of hyperemesis gravidarum is multifactorial, the most recent evidence suggests that early treatment of nausea and vomiting of pregnancy may reduce progression to hyperemesis gravidarum, as recommended in the study 1. Treatment typically begins with dietary modifications, followed by medications like vitamin B6, doxylamine, ondansetron, or promethazine if needed, and may require IV fluids and hospitalization in severe cases, as noted in the study 1.
From the Research
Causes of Hyperemesis Gravidarum
The exact cause of hyperemesis gravidarum is largely unknown, but it is believed to be a multifactorial condition involving genetic, biological, and psychological factors 2, 3. Some studies suggest that hormonal changes during pregnancy, such as the increase in ovarian and placental hormones, may play a role in the development of hyperemesis gravidarum 2, 4.
Possible Contributing Factors
Some possible contributing factors to hyperemesis gravidarum include:
- Genetic predisposition 3
- Infectious factors 4
- Psychiatric factors 4
- Hormonal contributions, such as changes in progesterone, estrogen, and HCG levels 4
- Metabolic factors, such as nutritional deficiencies 3
- Anatomical factors, such as gastrointestinal trauma 3
Current Understanding
Despite extensive research, the precise mechanism underlying hyperemesis gravidarum remains unclear 2, 3. The condition is thought to be related to a combination of factors, rather than a single cause. Further research is needed to fully understand the pathogenesis of hyperemesis gravidarum and to develop effective treatments 3, 4.