Dear Doctors: My daughter suffered from hyperemesis while she was pregnant two years ago, and it was truly a miserable pregnancy. Is there a way to prevent this for future pregnancies? I understand this condition is linked to the hormone GDF-15 and read that the key is to suppress it before it begins.
Dear Reader: Hyperemesis is the medical term for extreme and persistent vomiting. When it happens during pregnancy, it’s called morning sickness. As many mothers can attest, even mild morning sickness is no picnic, and the queasy feelings and nausea often extend well beyond the morning hours. Even without active vomiting, it makes getting through the day a challenge.
It’s estimated that up to 80% of women experience some morning sickness during pregnancy. In some cases, the condition can become severe, known as hyperemesis gravidarum. Hyperemesis gravidarum is frequent and intense vomiting that can lead to dehydration, electrolyte imbalance and dangerous weight loss. The condition often requires medical care. In some cases, women are hospitalized to receive IV fluids and nutritional support.
As recently as 2018, the cause of morning sickness was unclear. But emerging genomic technologies have helped scientists identify growth differentiation factor 15 (GDF-15) as a key contributor. This is the hormone you mentioned. The placenta produces a lot of GDF-15 early in pregnancy. It signals to the body that pregnancy has begun and to modulate immune response to tolerate the growing fetus.
GDF-15 also appears to regulate appetite. It may be a protective measure to steer the mother away from potentially harmful toxins and toward nutritional needs. Because concentrations of the hormone are so high and many women are sensitive to it, varying degrees of morning sickness often occur.
Several large studies found a correlation between very high levels of GDF-15 and the likelihood of developing hyperemesis gravidarum. This has led to the pursuit of targeted treatments. One approach is to suppress production or activity of the hormone during pregnancy. This may be risky due to the role GDF-15 plays in regulating immune response so that the body does not treat the fetus as a foreign presence. Another is to desensitize the mother to the hormone before pregnancy begins. Acclimating the body to the hormone before the placenta produces a lot of GDF-15 has emerged as a possible safer approach.
These are promising directions for easing the misery and risks of hyperemesis gravidarum, but they remain experimental for now. Because pregnancy involves the well-being of both the mother and her baby, testing any new treatment’s safety, effectiveness and side effects is complex.
Women who have had hyperemesis gravidarum can prepare for a future pregnancy by consulting their doctor before conception. A doctor can review medical history and make plans for early interventions if the mother's health appears at risk. Having good nutrition, starting prenatal vitamins and arranging follow-up care early in pregnancy may help lessen the severity if hyperemesis recurs.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
