Though many pregnant women experience morning sickness, about 3 percent are hospitalized each year with hyperemesis gravidarum, a severe form of pregnancy-related nausea that can result in constant vomiting, the inability to eat, and weight loss, among other symptoms. The Hyperemesis Education & Research Foundation estimates that hyperemesis gravidarum may occur in as many as 10 percent of pregnancies, since the only reported cases are the most severe ones that result in hospitalizations.  In this blog post, we will explore the causes, symptoms, and treatment options available for hyperemesis gravidarum.
Causes of Hyperemesis Gravidarum
Researchers and physicians are not sure what causes hyperemesis gravidarum, but they have some theories. The first, and most widely studied idea is that the increase in the hormones human chorionic gonadotrophin and progesterone causes hyperemesis gravidarum, but researchers still have some questions about the consistency of this connection. Another theory links increases in a thyroid hormone called thyroxine with hyperemesis gravidarum. Other potential causes that scientists have investigated include nutrient deficiencies, defects in the digestive tract, and psychological causes. It is now known that hyperemesis gravidarum does not have a psychological cause, though it can have extensive psychological effects. 
Symptoms of Hyperemesis Gravidarum
Though typical morning sickness and hyperemesis gravidarum both show up between weeks two and six of pregnancy, the similarities end there. Hyperemesis gravidarum is marked by extreme nausea, excessive vomiting, and increased saliva, which can make vomiting worse. Pregnant women with hyperemesis gravidarum often cannot eat at all and may not even be able to keep water down. Weight loss (sometimes as high as 10 percent of body weight), malnutrition, and dehydration can also accompany hyperemesis gravidarum. In severe cases, women must receive intravenous fluids or nutrition via feeding tube in the hospital. 
Most women with morning sickness are able to work and take care of themselves at some point during the day. But pregnant people with hyperemesis gravidarum often cannot function normally, which in some cases results in relationship strain and job loss. Understandably, stress levels can be extremely high during a hyperemesis gravidarum pregnancy, which leads to an increased risk of developing prenatal or postpartum mood disorders, like anxiety and depression. Plus, stress can sometimes make physical symptoms, such as vomiting and nausea, worse. 
For more than half of women with hyperemesis gravidarum, nausea and vomiting ends by week 21, about halfway through pregnancy. But in some cases, hyperemesis gravidarum continues throughout pregnancy, which can result in complications like liver failure and difficult delivery. Nausea and vomiting that lasts beyond 21 weeks of pregnancy can also have effects on the baby, though most women with hyperemesis gravidarum do have healthy babies, especially if they seek treatment. [1,3]
Treatment and Outlook for Hyperemesis Gravidarum
If you think you might be experiencing hyperemesis gravidarum during your pregnancy, especially if you are losing weight and cannot keep food and water down, call your care provider. Nausea and vomiting during pregnancy is not your fault, and you can get help. Your doctor or midwife will have suggestions for ways to manage your pregnancy-related nausea and vomiting, even if it is not as severe as hyperemesis gravidarum.
Your doctor might prescribe medication if you do have hyperemesis gravidarum. If you feel worried about taking medication, you are not alone. But the benefits of being able to function in your daily life and get adequate nutrition for yourself and your baby generally outweigh risks of taking medication. Some medication options include Benadryl and Zofran. 
If your symptoms of hyperemesis gravidarum are severe or have gone untreated for a while, you might need intravenous nutrition or fluids, which you can get in the hospital. If you are able to eat anything, do so, even if it has little nutritional value. Be prepared with snacks nearby in case your nausea goes away suddenly. Examples of foods and drinks that women with hyperemesis gravidarum have been able to consume successfully are: raspberry tea, ginger ale, honey, and potato chips. In some cases, your care provider might also suggest bed rest, an option you should carefully talk over with him or her. Regardless of what you decide about bed rest, it is important to give yourself time to rest as much as you feel you can. 
Despite the challenges of having hyperemesis gravidarum, most women who experience it do go on to have healthy babies. And if you have hyperemesis in one pregnancy, you have at least a 50 percent chance of having it the next time you are pregnant. If you feel as though you might be depressed or anxious as a result of your nausea and vomiting, it might help to consult a mental health professional, such as a psychologist or counselor. Support groups for women with hyperemesis gravidarum might also be helpful.