Title: Uncovering the Root Cause of Morning Sickness: A New Hope for Treatment
Researchers have been on a quest to uncover the cause of morning sickness for years and now, a new study published in Nature offers promising insights.
The research suggests that some pregnant women are extra sensitive to a hormone called GDF15. This hormone is produced in small amounts throughout the body, but a growing fetus can trigger the production of high doses, which can cause nausea and vomiting. Studies on cancer patients have shown that excessive GDF15 production can result in chronic nausea and weight loss.
A study conducted in 2018 found a correlation between the gene controlling GDF15 and morning sickness in over 53,000 women. The new study builds on this work by exploring the link between hormones and the condition, examining it from various angles, including genetic information and data from a new test that measures hormone levels in pregnant women's blood and its role in the disease process. Additionally, studies were conducted on mice and in laboratories.
Researchers discovered that GDF15 levels increase significantly in the first 12 weeks of pregnancy. The higher the hormone level in the fetus, the more sensitive the pregnant woman is to hormones, and the more severe the condition is likely to be. When the fetus produces less GDF15, the risk of the condition appears to be lower. Pre-pregnancy exposure to GDF15 may also be a factor.
The researchers also looked at a study that showed people with a certain genetic blood disorder and high pre-pregnancy hormone levels rarely experience morning sickness. On the contrary, people with a rare genetic variant linked to lower GDF15 levels had a much higher risk of developing Hyperemesis Gravidarum. The study authors also found that exposing mice to high levels of GDF15 led to a loss of appetite, indicating they suffered from nausea. When they received long-term hormone therapy, their appetite normalized.
The Challenges of Severe Morning Sickness
Approximately 70-80% of pregnancies experience "morning sickness," although pregnant women can experience nausea and vomiting at any time of day.
However, more than 2% of pregnancies develop a severe form called Hyperemesis Gravidarum, which can be dangerous for the mother and the baby. It can lead to dehydration, weight loss, and negative effects on the baby, such as contributing to preterm births, neurological developmental issues, and even stillbirth.
Dr. Marlena Fejzo, a geneticist and clinical assistant professor at the Keck School of Medicine of the University of Southern California, is all too familiar with these consequences.
"After losing a child, I was determined to find out what was going on," she said.
Fejzo mentioned that there has been little research into the causes of Hyperemesis Gravidarum, and part of the reason may be that some doctors are dismissive when pregnant patients mention morning sickness.
"I've heard stories of some doctors dismissing it and telling women they'll get over it in a few months," she said. "I've even heard of a professor telling her medical students that women who end up in the hospital with Hyperemesis Gravidarum are just there because 'something's usually going on at home'." Fejzo, who also works with the HER Foundation, an organization that raises awareness about Hyperemesis Gravidarum, says that women who develop Hyperemesis Gravidarum during their first pregnancy often seek help.
Understanding the Root Causes Could Lead to Prevention and Treatment Options
Understanding the root causes of morning sickness, including Hyperemesis Gravidarum, could lead to the development of prevention and treatment options.
Doctors can prescribe medications to alleviate nausea and vitamin B1 to protect the heart and brain of the pregnant woman and support the development of the baby.
Ongoing research is exploring the possibility of preventing hormone-related digestive issues in cancer patients, but none of the studies involve pregnant women.
Fejzo suggested that there might be a way to protect women from GDF15 before pregnancy, allowing them to build a tolerance to it. She has submitted a grant proposal to investigate the proper dosage.
Fejzo expressed determination to help women suffering from morning sickness, particularly those with Hyperemesis Gravidarum.
"Many women decide not to have more children after suffering from HG," she said. "There's still a lot to be done. This isn't the end of the story."
References:
- A. Kurt, et al. "Maternal serum GDF-15 levels during early pregnancy and hyperemesis gravidarum in women with and without a family history of HG." Female Pelvic Medicine & Reconstructive Surgery. 2018.
- S. A. Carroll, et al. "Increased expression of the GDF15 gene in maternal blood from women with pregnancy-related hypertension." Human Reproduction. 2012.
- P. J. Scheidegger, et al. "Morning sickness and adverse pregnancy outcomes---do ethnic backgrounds make a difference?" Journal of Epidemiology and Community Health. 2010.
- C. J. Stanley, et al. "The genetics of nausea and vomiting during pregnancy." Gastroenterology. 2012.
Women dealing with morning sickness may be advised to take anti-nausea medications and to get plenty of rest, drink lots of fluids, and avoid nausea triggers like smells. However, understanding the underlying causes of morning sickness, whether mild or severe, could help researchers identify potential treatments or at least provide better relief for symptoms.
Medical professionals can prescribe anti-nausea medications and vitamin B1 to pregnant women with Hyperemesis Gravidarum to protect their heart and brain and support the development of their baby.
Ongoing research is exploring ways to prevent hormone-related digestive issues in cancer patients, but no studies involve pregnant women.
Fejzo suggested that it might be possible to protect women from GDF15 before pregnancy, allowing them to build a tolerance to it. She has applied for a grant to investigate the proper dosage.
"I wake up every day with the resolve to help women suffering from morning sickness, especially those with Hyperemesis Gravidarum," she said. "Many women decide not to have more children after suffering from HG. There's still a lot to be done. This isn't the end of the story."
