Shortness of breath during pregnancy

Shortness of breath is a common and normal part of pregnancy. It affects nearly 60 percent of pregnant women. Find out why.

Why do pregnant women experience shortness of breath?

At the start of pregnancy

During the first trimester, you may experience shortness of breath due to changes in your respiratory system, which must now meet the oxygen needs of the placenta and the fetus. To meet these new needs, your oxygen consumption increases by 20%.

Toward the end of pregnancy

The pressure caused by your uterus expanding against your diaphragm decreases your lung capacity, which can cause breathlessness. As a result of that pressure, your diaphragm becomes more stretched. It then loses some of its elasticity, resulting in shortness of breath.

The expanding uterus also causes the contents of the abdomen (for example, the stomach) to move against the diaphragm, making it harder for the lungs to stretch. You may then tend to breathe more from your abdomen than from your rib cage.

Toward the end of pregnancy, pregnant women often feel short of breath when they exert themselves. This is perfectly normal, as the body requires more oxygen at this stage. Your breathing adjusts by becoming faster.

If this is your first pregnancy, you may experience a decrease in shortness of breath in the last few weeks before giving birth. At this stage, the baby settles into the mother’s pelvis, thus reducing pressure on the diaphragm. For subsequent pregnancies, this sensation is less common, as the baby often drops during labour.

How can you reduce the discomfort of shortness of breath?

Here’s what you can do to feel less out of breath.

• Watch your posture and keep your back straight.
• Rest in a position that makes it easier to breathe. For example, you can lie on your left side, elevate the head of your bed slightly, or use an extra pillow to sleep in a semi-seated position.
• Repeat the following exercise until you can breathe more easily:
  - Stand with your feet flat on the floor or lie on your back with your legs bent.
  - Inhale slowly while raising and stretching your arms over your head. This movement stretches the rib cage.
  - Exhale slowly while bringing your arms back down to your sides.
• Avoid places where people smoke whenever possible.Secondhand smoke irritates the airways and can increase your feeling of being short of breath.
• Stay active while respecting your energy level and limits. For example, you can do prenatal yoga, go swimming, or take a walk.
• Avoid eating large meals, as an overfilled stomach can increase pressure against the diaphragm.
• Dress comfortably, avoiding tight-fitting clothes around your stomach and chest.

When should you consult a doctor?

Severe shortness of breath during physical exertion or while at rest may also be related to physiological anemia of pregnancy (when blood volume increases faster than red blood cell production). Consult your doctor if your shortness of breath is accompanied by fatigue, weakness, paleness, or dizziness.

• Calf pain
• Headaches
• Dizziness
• Palpitations
• Abdominal or chest pain
• Vision problems

Scientific review: Anouk Landry, nursing staff manager for the Obstetrics-Gynaecology Department, CHU Sainte-Justine Research and copywriting:The Naître et grandir team Updated: April 2026

Photo: GettyImages/Prostock-Studio