Low blood pressure, also called hypotension, is common during pregnancy, especially during the first trimester. Women tend to experience short-term hypotension that resolves within a few moments of the onset of symptoms. Symptoms include dizziness, fainting, fatigue and blurred vision. Other symptoms that are more characteristic with persistent hypotension include nausea, rapid but shallow breathing, fatigue and depression, explains MayoClinic.com.
Widened Blood Vessels
The American Pregnancy Association points out that low blood pressure during pregnancy results from the blood vessels widening and relaxing to increase blood flow to the baby. The blood returns to the mother at a slower rate and creates a decline in blood pressure. MayoClinic.com explains that a woman can lose as much as five to 10 points on her systolic blood pressure and 10 to 15 on her diastolic reading during the first 24 weeks of pregnancy. After birth, the woman's blood pressure will return to normal.
Lying Down
When a pregnang woman lies down, her uterus puts pressure on major blood vessels, including the aorta and vena cava, explains the American Pregnancy Association. This type of hypotension is called supine hypotension. Supine hypotension can be prevented by resting in an elevated position or sleeping on the side.
Standing Quickly
Postural hypotension is a type of low blood pressure that occurs when a woman rises quickly from sitting, squatting or kneeling. As she rises, gravity makes the blood work harder to reach the heart, leading to a decrease in blood pressure. To prevent this type of hypotension, rise slowly.
Dehydration
Pregnant women urinate frequently as the kidneys prepare to process the increased waste provided by the baby. With this pregnancy symptom and a woman's overall need to drink plenty of water, dehydration can occur easily. MayoClinic.com points out that dehydration can lead to reduced blood pressure. Blood cells are mostly made of water and require plenty of fluids to continue reproducing.
