A: There are several reasons why you may feel faint. First, there are many circulatory changes during pregnancy. Your blood vessels dilate during pregnancy allowing your blood pressure to decrease in the second trimester. If you aren't disciplined about drinking lots of fluids each day, you may become dehydrated. Changing positions suddenly (like when you get up from bed first thing in the morning) can result in a drop in blood pressure, and a temporary reduction of blood flow to your head, leading you to feel light-headed. Try to drink at least eight full cups of water or other liquids each day, and change positions slowly.

Second, standing for long periods of time will result in pooling of blood in your lower legs. Along with an increase in swelling of your feet and ankles, you may feel light-headed or faint. Try to intersperse prolonged standing with walking or sitting, and wear good support hose to minimize retaining fluid in your legs. (When I was pregnant and had to stand for long periods of time I found wearing pressure-graded support hose was a life-saver.)

Finally, your faintness may be caused by low blood sugar. Your body continuously utilizes calories to nourish your growing baby, whether or not you eat regularly. This can result in low blood sugar. Try to eat frequent meals throughout the day, and include a source of complex carbohydrates (such as whole grain breads or cereal) at each meal to keep your blood sugar in a normal range for many hours. If you do feel faint, drink some juice or eat a piece of fruit to give your blood sugar an immediate boost.

If you feel faint frequently, discuss this with your doctor. He/she may recommend a blood test to see if you are anemic, and may wish to evaluate you for other causes of fainting.