Feeling faint or dizzy is a common pregnancy symptom. Although women in the first trimester may experience this symptom more frequently, it can occur throughout the entire pregnancy for many women. Although dizziness is usually temporary and harmless, women who experience abdominal pain, bleeding, blurred vision, headaches, palpitations or are concerned about the dizziness should always call a doctor.
Blood Vessel Changes
Pregnancy hormones cause a woman's blood vessels to widen to increase the blood flow to the baby. This can cause her blood pressure to be lower than normal, resulting in a reduced blood flow to her brain, which often triggers feelings of dizziness or lightheadedness, according to the American Pregnancy Association.
Growing Uterus
A pregnant woman's growing fetus can slow the circulation in her legs while she lies down, especially in the second and third trimesters. The medical advisory board at BabyCenter.com notes that 8 percent of pregnant women in their second and third trimester develop supine hypotensive, a condition that increases heart rate, blood pressure, and feelings of dizziness and lightheadedness when they lie on their back. Pregnant women should avoid lying on their backs for this reason.
Standing Up Quickly
Sitting causes blood to pool in the lower legs and feet. When a pregnant woman stands up too quickly, her body sometimes doesn't adjust fast enough to return the blood from the legs to the heart. This causes her blood pressure to drop suddenly, which leaves her feeling faint or dizzy, explains the medical advisory board at BabyCenter.com.
Dehydration or Low Blood Sugar
Pregnant women who do not eat or drink enough may find themselves getting dizzy or lightheaded. A woman's body requires more food when pregnant, so pregnant women should strive to eat small, frequent meals throughout the day. They should also drink approximately 8 to 10 glasses of water to avoid dizziness.
Anemia
Dizziness also plagues many pregnant women who are anemic. Anemia causes fewer red blood cells to carry oxygen to the organs, which brings about feelings of dizziness. Taking a prenatal vitamin each day and eating an iron-rich diet helps prevent anemia in pregnancy, but doctors may prescribe an iron supplement for pregnant women who become anemic.
Overheating
Overheating can also cause dizziness or lightheadedness. Overexertion, crowded places, hot baths or showers, and warm clothing can all cause overheating in pregnant women. Avoiding these things and keeping cool can prevent this dizziness from occurring.
Excessive Exercise
Although moderate exercise during pregnancy is beneficial, overdoing it can cause hyperventilation and dizziness. Pregnant women should always take frequent breaks when exercising, and should stop and lie down if they begin to feel dizzy or tired.
