March 29, 2010
At some point during her pregnancy, a patient might complain of dizziness or “fainting.” However, the challenge is to determine if this is an isolated incident or does the patient need additional tests?
True fainting (or syncope) means that there has been a temporary loss of consciousness and the patient is no longer standing. This usually occurs when there is a temporary decrease in the blood flow to the brain. The most common reason patients faint is because of low blood sugar (hypoglycemia), especially during the first trimester. However, hypoglycemia does not explain all reasons for fainting.
During pregnancy, the blood vessels are opened wide (dilated) which sometimes decreases the amount of blood flowing within the chambers of the heart. It therefore beats slower. A slow heart beat (aka bradycardia) produces symptoms of dizziness or fainting. However, there are also serious conditions that also cause fainting and it’s important to know the difference. Listed below are examples of fainting that require additional tests:
- Fainting associated with a loss consciousness that lasts for greater than 15 minutes
- Fainting associated with loss of urine
- Fainting preceded by shortness of breath, light-headedness, chest pain and a fast heartbeat
- Fainting associated with significant disorientation, weakness of limbs, numbness and abnormal movements
Items 1, 2 and 4 require a neurology consultation to rule out a seizure disorder or a space-occupying tumor. Item 3 requires a cardiologist (heart specialists) to look for heart problems or, on rare occasions, a blood clot in the lungs. These are extremely rare conditions that most pregnant women will never experience.
Most pregnant women can avoid fainting episodes by drinking lots of fluids, avoid prolonged periods of standing, get up SLOWLY if sitting down for long periods of times and wear stockings that improve circulation. Thankfully, unless fainting has been associated with a serious condition, there will be no harm to the baby.