Nausea symptoms due to pregnancy can occur at any time of the day. Many pregnant women report feeling more nauseous each morning.
Nausea is a very common phenomenon in the early stages of pregnancy. According to Science News, 80% of pregnant women experience nausea during the first trimester. Among this group, 3% face severe and frequent vomiting, leading to weight loss, dehydration, and even hospitalization.
Although morning sickness can occur at any time of the day, symptoms often appear right after waking up. This is why, in English, it is referred to as “morning sickness.”
Why Does Pregnancy Cause Nausea?
Many women experience morning sickness at the beginning of pregnancy and by the end of the third month. (Photo: Pexels).
According to a publication in December 2023 in the journal Nature, pregnant women are particularly sensitive to a hormone called GDF15.
This hormone is scarce in normal individuals but increases significantly during fetal development, which can lead to nausea and vomiting.
Previously, studies conducted with cancer patients found that excessive production of GDF15 can cause nausea and weight loss.
In 2018, scientists discovered a link between GDF15 and nausea during pregnancy in 53,000 women.
Researchers found that GDF15 levels rise during the first 12 weeks of pregnancy. The higher the fetal hormone concentration, the more sensitive the pregnant woman becomes. They also observed that when mice were exposed to high levels of GDF15, they experienced loss of appetite and nausea.
In an interview with Live Science, Professor Clara Paik, a gynecologist at UC Davis Health, noted that reproductive hormone levels, especially human chorionic gonadotropin (hCG), are elevated during the first trimester. However, the exact mechanism by which hCG causes nausea in pregnant women remains unclear.
According to a 2016 review, some researchers speculate that hCG may induce nausea by stimulating the secretion of digestive fluids. The hormone also contributes to increased thyroxine levels—produced by the thyroid gland—which is related to regulating digestion and helps control appetite.
Morning sickness is caused by hormonal changes and genetic factors. (Photo: Unsplash).
According to Professor Adiele Hoffman, a general practitioner and medical advisor at the menstrual tracking app Flo Health, estrogen and progesterone hormones may also contribute to nausea symptoms.
“These hormones relax the muscles in the stomach and intestines, slowing down the digestive process. This means your last meal of the day may not be fully digested and can lead to regurgitation the next morning,” she explains.
Hormones may also explain why some individuals experience severe morning sickness while others do not.
“Hormone levels vary from person to person. How the body reacts to hormonal changes also differs,” Professor Hoffman notes.
Furthermore, a study published in 2019 in Nature Reviews Disease Primers indicated that genetic factors also determine the severity of morning sickness.
In addition to hormones and genetics, hypoglycemia or low blood sugar can exacerbate nausea.
According to a 2016 review, pregnancy can lead to lower blood sugar levels, which may drop more significantly at night due to the developing fetus’s energy needs. This is also why pregnant women often feel more nauseous in the morning.
Additionally, Professor Paik mentioned that nausea symptoms may be more pronounced in the morning due to not having breakfast and experiencing a drop in blood pressure after getting out of bed.
This expert noted that nausea symptoms can also increase with stress, anxiety, and fatigue. Not only pregnant women but also individuals who are not pregnant often experience nausea when stressed, as negative emotions can cause discomfort in the digestive system.
However, the good news is that morning sickness tends to resolve by the second trimester, around the fourth month of pregnancy.
How to Alleviate Morning Sickness?
Stanford Health advises pregnant women that it is not necessary to eat a lot in the first few months if experiencing nausea. Meals can be divided into smaller portions throughout the day to ensure you do not go hungry and that the fetus remains healthy.
Expectant mothers should avoid strong-smelling foods and not lie down after eating. Instead, pregnant women should opt for foods high in protein or carbohydrates and low in fats.
Moreover, to mitigate morning nausea, experts suggest having a light snack like crackers and resting before getting out of bed. Additionally, pregnant women should drink plenty of water throughout the day, consume ginger, peppermint, or suck on candies to help manage nausea.
In addition to focusing on diet, expecting mothers should also pay attention to their rest regimen. If feeling overly tired, future mothers can take multiple short naps each day and ensure they get 8-9 hours of sleep each night.
