Pregnancy: Dizzy

Here are some common causes of lightheadedness during pregnancy as well as the precautions you can take:

About eight percent of pregnant women in their second or third trimester develop a condition called supine hypotensive syndrome. If you have this condition, it means that when you lie on your back, your heart pumps less blood and your blood pressure drops, so you may feel anxious, lightheaded, and nauseated until you shift position.

To prevent this problem, lie on your side instead of flat on your back. A pillow placed behind you or under your hip can help you stay on your side (or at least tilted enough to keep your uterus from compressing the vena cava).

Eat and drink regularly. When you don't eat enough, you can end up with low blood sugar (hypoglycemia), which can make you feel dizzy or faint. This can happen much more easily when you're pregnant. Keep your blood sugar from getting too low by eating small meals frequently during the day instead of three large ones. Carry healthy snacks to eat when you get hungry on the go.

Dehydration can have a similar effect; stay well hydrated. Drink enough water until your urine is pale or clear.

Avoid overheating. Spending time in a hot room or taking a hot bath or shower can make your blood vessels dilate, lowering your blood pressure and making you feel woozy.

If you feel dizzy when you get too hot, avoid stuffy, crowded places and dress in layers so you can shed clothes as necessary. Take warm showers or baths instead of hot ones, and try to keep the bathroom cool.

Don't overdo it when you exercise. Exercise can sometimes cause you to hyperventilate and feel faint. Although exercise can help your circulation, be careful not to overdo it and stop if you feel tired or unwell.

Here are the specific reasons for this dizziness:

Vena Cava Compression: In the second and third trimesters (20+ weeks), lying or tilting back causes the uterus to compress the inferior vena cava, decreasing blood return to the heart by up to 30–40%.

Reduced Cardiac Output: Because the heart is receiving less blood, it pumps less blood out, causing a drop in blood pressure (hypotension).

Hormonal Changes: Early in pregnancy, higher levels of progesterone cause blood vessels to relax and widen, which can lower blood pressure and lead to dizziness.

Anatomical Positioning: The inferior vena cava runs on the right side of the spine. When tilting back or lying down, the weight of the uterus easily blocks this vein.

Iron Deficiency/Anemia: Pregnant women may have fewer red blood cells to carry oxygen, increasing the likelihood of feeling lightheaded.

Dehydration or Hunger: Skipping meals or not drinking enough fluids can cause blood sugar to drop, exacerbating the dizziness. 

If the dizziness is persistent, severe, or accompanied by symptoms like blurred vision, vaginal bleeding, or severe headaches, contact a healthcare provider. 

What can I do if I'm experiencing dizziness or lightheadedness in pregnancy?

Shift Position: Immediately turn onto your side (preferably the left) to relieve pressure on the vena cava.

Stay Hydrated & Eat Often: Keep water and small snacks handy to maintain blood sugar and hydration levels. 

Go outside, get fresh air, and loosening tight clothing.

Sometimes cooling yourself down helps: wet cloth on your forehead, drinking cool water, ice blocks etc.

Can I prevent dizziness in pregnancy?

You can take steps to minimize the risk of dizziness during pregnancy.

Don't stand up too fast. When you sit, blood pools in your feet and lower legs. If your body isn't able to adjust when you stand up, not enough blood returns to your heart from your legs. As a result, your blood pressure drops quickly, which can leave you feeling faint.

To prevent this, avoid springing up from your chair or bed. When you're lying down, sit up slowly and stay seated for a few minutes with your legs dangling over the side of the bed or couch. Then slowly rise from sitting to standing.

Your blood may also pool in your feet and legs when you stand in one place for a long time. If you're in a situation where you can't move around, try shaking your legs to promote circulation. Wearing support stockings can also help circulation in the lower half of your body.

Don't lie on your back. In the second half of pregnancy (20 weeks and onward), your growing uterus can slow the circulation in your legs by compressing the large vein (inferior vena cava) that returns blood from the lower half of the body to the heart and the pelvic veins. Lying flat on your back can make this problem worse.

To prevent this problem, lie on your side instead of flat on your back. A pillow placed behind you or under your hip can help you stay on your side (or at least tilted enough to keep your uterus from compressing the vena cava).