Scientists have found something important that might help us understand why pregnant women feel sick in the mornings. New hope for Morning Sickness, understanding and Potentially Treating Pregnancy-Related Nausea and Vomiting.
Think about those times when you’ve felt really sick, maybe from bad food or a bug that’s going around. It’s not fun, right? Now, picture feeling nauseous and throwing up regularly during a big part of your life. That’s what happens to four out of five women during pregnancy. Even in milder cases, it means feeling queasy, not wanting to eat, and throwing up.
For the three percent of women who have a more severe condition called hyperemesis gravidarum, things are even tougher. They might need to go to the hospital for treatment.
Hyperemesis gravidarum is when a pregnant woman experiences severe nausea and vomiting that makes it hard to eat or drink. This can lead to dehydration, lack of nutrients, and weight loss, which is dangerous for both the mother and the baby.
In 2022, nearly 20,000 women had to go to the hospital because of this condition, according to the Office of National Statistics.
Until recently, not much was known about why some women feel nauseous and vomit during pregnancy. Some people thought that the more you felt sick, the healthier the pregnancy, or that it was connected to how many babies you were having. However, real-life evidence shows that these ideas are not true. Nausea and vomiting during pregnancy can vary a lot in how severe it is and when it happens.
Even though people often call it ‘morning sickness,’ it can actually happen at any time of the day or night. It usually gets worse in the first 12 weeks and then gets better. But for many women, it continues throughout the entire pregnancy.
Good news has finally come after more than 20 years of research into the causes of severe nausea and vomiting during pregnancy. Dr. Marlena Fejzo, a geneticist at the University of Southern California Keck School of Medicine, led this breakthrough.
Dr. Fejzo was inspired to pursue this research because she suffered greatly from nausea and vomiting during her second pregnancy in 1999. Her symptoms were severe—she couldn’t eat or drink without vomiting, lost weight rapidly, and became too weak to stand or walk. Unfortunately, her doctor dismissed her symptoms, leading to hospitalization and a miscarriage at 15 weeks.
Partnering with 23andMe, a company that allows individuals to send their DNA samples for health and ancestry insights, Dr. Fejzo conducted a genetic study with women who had experienced severe pregnancy-related nausea and vomiting. She found an association between this condition and a variant in a gene that codes for a protein called GDF15, a hormone that acts on the brainstem.
GDF15 is released from the placenta in the first two trimesters of pregnancy. It likely plays a role in preventing the mother’s body from rejecting the baby, crucial for a healthy pregnancy. However, GDF15 is also known to regulate body weight and appetite. It is overproduced in cancer patients experiencing severe appetite and weight loss.
Building on this study, further research led by Dr. Fejzo and Prof Sir Stephen O’Rahilly from the University of Cambridge revealed that high levels of GDF15 were present in women with severe pregnancy-related nausea and vomiting. However, the hormone’s impact appeared to depend on the women’s sensitivity and their exposure to GDF15 before pregnancy. Women with high pre-pregnancy exposure had no symptoms despite elevated GDF15 levels.
It is theorized that prolonged exposure to GDF15 before pregnancy could provide a protective effect, making women less sensitive to the hormone surge caused by the developing baby. This unique relationship opens the door to more understanding and potentially a treatment—increasing exposure to the hormone before pregnancy could desensitize women, similar to controlled exposure therapy for allergies.
Conditions affecting women are often poorly understood, despite their high prevalence. Women’s healthcare is broad and complex, and ongoing research like this holds the promise of uncovering more knowledge and potential treatments.