Fainting is a temporary loss of consciousness that occurs when the brain is briefly deprived of sufficient blood flow and oxygen. While experiencing a sudden loss of consciousness can be alarming, especially during pregnancy, it is a relatively common occurrence for expectant mothers. Understanding the underlying reasons for this event and knowing when it shifts from a common pregnancy symptom to an urgent medical concern is important for maternal and fetal well-being.
Understanding Common Causes of Fainting During Pregnancy
The physiological changes that support a growing baby predispose pregnant individuals to lightheadedness and fainting episodes. Early in pregnancy, hormonal fluctuations trigger vasodilation, leading to a drop in overall blood pressure. This drop, combined with the body’s effort to increase blood volume by up to 50%, can sometimes result in orthostatic hypotension, a sudden drop in blood pressure when changing positions.
The increased volume of blood often pools in the lower extremities, meaning less blood returns quickly to the heart and subsequently to the brain. In the later stages of pregnancy, the enlarging uterus can compress the inferior vena cava, the major vein that returns blood from the lower body to the heart, when the pregnant person lies flat on their back. This compression can reduce the blood flow back to the heart, causing a rapid decrease in blood pressure and leading to a fainting episode known as Supine Hypotensive Syndrome. Other contributing factors can include low blood sugar, dehydration, anemia, or overheating.
Immediate Action: What to Do Right After Fainting
If you feel signs of lightheadedness, such as ringing in the ears, blurred vision, or clammy sweating, the immediate action is to prevent injury by sitting or lying down immediately. If you are able to lie down, elevate your feet slightly higher than your head to encourage blood flow back toward the brain. This simple position can often resolve the presyncope symptoms before unconsciousness occurs.
If a fainting episode occurs and you regain consciousness, the safest recovery position is to lie on your left side. Lying on the left side ensures the weight of the uterus is shifted away from the major blood vessels in the back, maximizing circulation to both the mother and the baby. After recovering, you should remain still for at least 20 to 30 minutes, slowly drink some water, and have a small snack to stabilize blood sugar levels before attempting to stand again.
Urgent Warning Signs: When to Contact Your Healthcare Provider
While most episodes of syncope during pregnancy are benign, a fainting spell should be reported to your healthcare provider, and certain accompanying symptoms require immediate medical attention. If the fainting led to a physical injury, such as hitting your head, or if you fell and landed directly on your abdomen, you must contact your provider or go to the Emergency Department right away for a full assessment.
Any fainting accompanied by other severe symptoms suggests a more serious underlying condition. These include severe abdominal pain, vaginal bleeding, persistent chest pain, or difficulty breathing. A severe, sudden headache, changes in vision, or confusion following the episode are also urgent warning signs.
If the fainting is not triggered by standing up quickly but occurs while you are already lying down, seek immediate concern. If you notice a significant change in the baby’s movements, or if the fainting is recurrent or followed by a fit or convulsion, seek emergency help. When contacting your provider, be prepared to state your current week of gestation, the duration of the unconsciousness, and a precise description of any symptoms that occurred before, during, or after the event.