The exact cause of nausea and vomiting during pregnancy is unknown, but doctors have identified that it’s probably a combination of several changes happening inside your body. These changes include:
- An increase in human chorionic gonadotropin (hCG)– During early pregnancy, hCG is produced by cells in the placenta, which nourishes the newly fertilized egg. Pregnancy tests work by checking the presence of hCG on your urine, and research has shown a correlation between the intensity of nausea and the amount of hCG present in your body.
- An increase in estrogen production– Estrogen also rises rapidly during pregnancy and might be another culprit for the nausea and vomiting.
- An enhanced sense of smell – It’s not a secret that a lot of women have an enhanced sense of smell during pregnancy, and you might feel overwhelmed and nauseous when smelling certain odors. No one knows the exact reason for this heightened sensitivity, but researchers suggest that it is caused by the increased estrogen levels.
- A more sensitive digestive system – During early pregnancy, the stomachs of women become more sensitive and could be the cause of morning sickness.
- Increased stress – Some doctors suggest that the pregnant body’s natural, albeit abnormal, response to stress is nausea and vomiting, however there is no evidence that supports this claim.