Morning sickness, that unpleasant nausea and vomiting many pregnant women experience, is primarily caused by hormonal changes and possibly lower blood sugar during early pregnancy. While the exact cause remains elusive, research strongly suggests a connection to elevated levels of pregnancy hormones, specifically human chorionic gonadotropin (hCG) and estrogen. A recent study from USC and the University of Cambridge highlights the role of a fetal hormone, and a mother's sensitivity to it, in causing this condition. [^1, ^2, ^3, ^4, ^5]
Factors that Exacerbate Morning Sickness:
Several factors can worsen morning sickness symptoms:
- Hormonal fluctuations: The dramatic increase in hCG and estrogen levels in early pregnancy is a key suspect. [^3, ^5, ^9]
- Blood sugar levels: Low blood sugar can contribute to nausea. [^1, ^4]
- Emotional stress and fatigue: Stress and exhaustion can intensify symptoms. [^1, ^4]
- Diet and Smell: Certain foods or strong smells can trigger nausea. [^3]
- Multiple pregnancies: Morning sickness tends to be more severe in women carrying twins or triplets. [^1]
The Role of GDF15: A Breakthrough in Understanding
Recent research identifies GDF15, a hormone produced by the fetus, as a significant factor in morning sickness. The study suggests the amount of this hormone circulating in the mother's blood, combined with the mother's sensitivity to it, plays a crucial role. [^2, ^6, ^10]
In summary, while the complete picture is not yet fully understood, the leading causes are hormonal changes and possibly low blood sugar, further complicated by external factors such as stress and diet. A new focus on the role of the fetal hormone GDF15 provides a deeper insight into this common pregnancy ailment.
[^1]: Mount Sinai, Cleveland Clinic, and NHS websites on Morning Sickness.
[^2]: USC and University of Cambridge study on the cause of pregnancy sickness.
[^3]: Mayo Clinic information on Morning Sickness.
[^4]: Better Health Channel information on Morning Sickness.
[^5]: Information from various sources cited in this answer.
[^6]: PubMed article on a mechanism protecting the mother and embryo.
[^7]: Cambridge University article on pregnancy sickness cause.
[^8]: KidsHealth information on Hyperemesis Gravidarum (severe morning sickness).
[^9]: New York Times article on the cause of severe morning sickness.
[^10]: Other research articles cited and combined for a detailed explanation.
