During the first two trimesters of pregnancy, many women experience low blood pressure, or hypotension, as their circulatory system rapidly expands. In fact, it is common for a woman's blood pressure to drop as much 10 points for both systolic and diastolic readings. While blood pressure usually returns to normal post-pregnancy, during pregnancy women should be on the lookout for several dangers that may be cause for concern.
Dizziness
While many women are able to adjust to having lower blood pressure during pregnancy, dizziness or lightheadedness are common side effects for those who cannot. Pregnant women should take care not to lie on their backs as the uterus begins to grow large, as this can put pressure on the body's major blood vessels and cause what doctors refer to as supine hypotension; side sleeping can help prevent or alleviate this problem. Postural hypotension occurs when gravity causes a quick drop in blood pressure when getting up too quickly from a sitting, squatting or kneeling position; this can be avoided by getting up slowly.
Fainting
Vasovagal syncope can occur when blood pressure drops while straining to cough, urinate or have a bowel movement during pregnancy. In addition to feeling dizzy, many women also faint. BabyCenter recommends that pregnant women lay on their left side as soon as signs of faintness begin in order to maximize blood flow to the heart and brain. If lying down is not practical, a pregnant woman can sit with her head between her knees.
Treatment
Low blood pressure is sometimes caused by dehydration in the pregnant woman. Drinking plenty of fluids can help combat this. Some medications are generally safe to use during pregnancy to combat low blood pressure, but a physician will weigh the risks and benefits. Some doctors may suggest changing the diet to increase salt intake, though again the risks and benefits must be carefully considered.
