During the Victorian era, fainting was an unsophisticated way of recognising if a woman was pregnant. Amazingly enough, this physical sign was probably not far from being accurate.
Why fainting happens
Fainting during early and middle pregnancy (up until about 28 to 30 weeks) is a very common experience. It happens because the woman's blood vessels naturally relax and dilate under the influence of the hormone progesterone, lowering her blood pressure. Fainting is not usually a problem, just a little embarrassing if you do it in public!
Fainting may happen because:
The pregnancy hormone progesterone relaxes the walls of the blood vessels, making the blood 'pool' more in the woman's hands and feet and at times drain more rapidly away from her head (especially when getting up from a sitting or lying position). The medical term for this is 'postural hypotension'. Dizziness and fainting can also happen if you are in a hot environment.
A woman's blood pressure is naturally in the lower range of normal (around 90 / 50 to 110 / 60). Women with a lower blood pressure tend to experience dizziness and fainting more often than women with a higher blood pressure.
Your blood sugar level is low because you are not eating enough, or regularly. Pregnant women tend to be more susceptible to this because their metabolism increases by about 20% (meaning they process the food in their body more rapidly).
Sometimes dizziness and fainting can be a combination of all of the above. Also, be aware that some women will become faint if they lie on their back during late pregnancy. This is because the heavy uterus is capable of compressing a major blood vessel leading to the heart in some women. This is known as 'venal caval compression').
NOTE: In rare cases constant fainting and dizziness can be related to a heart condition. If it is happening regularly you may need to have some tests done. If you are concerned about your fainting, consult with your caregiver.
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