Dizziness and faintness
Throughout pregnancy, occasional dizziness or feelings of faintness can be a problem.
In early pregnancy, feeling faint may occur even when you are sitting down and is likely to be due to low blood sugar. This can happen as a result of not eating enough, a common problem at this stage of pregnancy when many women suffer from morning sickness. In the second trimester, dizziness or faintness that comes on when getting up from a sitting position or as a result of standing for long periods is likely to be caused by low blood pressure. Blood pressure is lowered in pregnancy because the pregnancy hormone progesterone softens blood vessels to enable blood to flow more freely to your baby. When you stand, the low blood pressure may mean that not enough blood reaches your brain, leading to dizziness and faintness.
As pregnancy advances, you may find that you feel dizzy lying on your back. This happens because in this position the heavy uterus puts pressure on the main blood vessels running through the trunk and reduces the blood flow to the brain.
What to do
To help prevent low blood sugar, have small snacks of foods high in complex carbohydrates (see Get carb loading). Staying well hydrated, taking regular breaks from work, not standing in one position for too long, and getting fresh air are also helpful in preventing faintness. If you start to feel dizzy, sit down and put your head between your legs, which will relieve the unpleasant feeling. Stay seated until you feel completely recovered and then get up slowly. Any time you feel dizzy or faint, call your doctor immediately, especially if you also have stomach pain, vaginal bleeding, blurry vision, headaches, or heart palpitations, or the dizziness is persistent. If you have fainted and bumped your head or injured any part of your body then you should go to the hospital for a checkup.
If you experience dizziness when lying on your back, turning onto your side will quickly help you feel better. Lying on your left side is preferable because this helps to pump blood around the body.
A feeling that your heart is racing, or beating irregularly is common in pregnancy, particularly between 28 and 32 weeks, but can occur at any time.
The reasons for palpitations remain unclear and hypotheses range from the effect that progesterone has on the heart muscle, to the heart coping with the extra blood flow needed to maintain both mother and fetus.
What to do
Palpitations are usually fleeting and nothing to worry about. However, if you have frequent palpitations or they are accompanied by chest pain, dizziness, or breathlessness, you should consult your doctor. If you have a history of heart disease or a heart abnormality, seek advice immediately.