What causes dizziness in pregnancy?

What causes dizziness in pregnancy?

Hormonal and blood pressure changes

Deirdre de Barra, head of pregnancy information at the pregnancy charity Tommy’s, says there are lots of reasons why you might feel dizzy or faint during pregnancy.

The most common reason is hormonal changes," she says. "Pregnancy symptoms are different for everyone, with some people’s increased hormone levels leading to more severe dizziness and nausea - often called morning sickness - than others. Other causes of dizziness might be low blood pressure."

Low blood pressure - or hypotension - can occur in pregnancy because more blood is rerouted to the baby. This can make you feel dizzy, especially when you move from sitting to standing. At your prenatal appointments, your doctor or midwife will check your blood pressure to make sure it’s within a normal range.

Sickness or hyperemesis gravidarum

Sickness may make you feel dizzy and unsteady. Nausea and vomiting is believed to be caused by a rapidly rising blood level of a hormone called human chorionic gonadotropin and can leave you feeling light-headed.

Although it’s often called morning sickness, it can happen at any time in the day or night. For some women, the sickness gradually disappears after the 12th week of pregnancy, when you enter the second trimester - but this isn’t always the case.

Severe sickness, called hyperemesis gravidarum, affects around 3 in 100 people with pregnancy sickness and is debilitating¹. It can cause dehydration, weight loss, and electrolyte imbalances, when you have too much or not enough of certain minerals in your body - so seek medical help as quickly as possible. To treat hyperemesis gravidarum, your doctor may prescribe you an anti-sickness medication or recommend you go to hospital so you can receive extra fluids and be monitored.

Ectopic pregnancy

Dizziness can result from an ectopic pregnancy, which is when a fertilised egg implants itself in your reproductive system - such as in the fallopian tubes - outside of the womb. When this condition occurs, the pregnancy isn’t viable.

You may experience dizziness, pain in the abdomen and vaginal bleeding. Your doctor will have to perform a procedure or prescribe a medication to remove the fertilised egg.

An untreated ectopic pregnancy can be a medical emergency- so if you experience any of these symptoms, you should go to your local accident and emergency department immediately.

Pre-eclampsia

"Feeling dizzy due to headaches which don’t go away with paracetamol, and blurred or flashing vision could be a sign of pre-eclampsia," says de Barra.

Pre-eclampsia is a serious condition that affects some pregnant women, usually after the 20th week of pregnancy or shortly after delivery. It is a combination of raised blood pressure and often protein in your urine or problems with the kidneys or liver.

"Other symptoms might include swelling of the face, hands or feet, a general feeling of being unwell, feeling sick and pain below the ribs," says de Barra.

"Contact your midwife or healthcare provider straight away if you have any of these symptoms or a combination of them."

Pressure from your womb

From around week 13 to when you are ready to have your baby (second and third trimesters) you may feel dizzy because your womb may press on your blood vessels as it gets larger. It’s important to move carefully and to avoid standing up too quickly.

Lying on your back

Lying on your back later in your pregnancy can also cause dizziness because your womb can prevent blood flow from your toes and legs to your heart. Therefore, you should lie on your side when sleeping or resting. A pregnancy pillow can help you get more comfortable at night.

It's important to look out for signs of feeling faint to avoid falling, especially from week 27 onwards. Stand up slowly and reach for support.

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How to manage dizziness in pregnancy

"If you feel dizzy or faint, sit or lie down until the feeling goes away,” says de Barra. "Tell your midwife or doctor about it. Make sure you stay hydrated."

If you are concerned about you or your baby’s health, it’s always safer to be checked out by your doctor, midwife or the maternity assessment unit at your hospital.

Further reading

1. Tommy's: Morning (pregnancy) sickness and hyperemesis gravidarum.