Do you feel like you can’t get enough air? Are your ankles swollen? Welcome to your third trimester of pregnancy.

What’s the first thing you should do? Stop worrying. Shortness of breath and water retention, or edema, are common in your last weeks of pregnancy. These symptoms can sometimes indicate a condition you should be concerned about, but only rarely. Here’s what’s going on.

What’s causing shortness of breath?

In the last trimester of pregnancy, your growing baby pushes your uterus against your diaphragm. The diaphragm is moved up about 4 centimeters from its prepregnancy position. Your lungs are also somewhat compressed. This all means that you’re unable to take in as much air with each breath.

This doesn’t mean, however, that you’re getting less oxygen. At the same time that your lung capacity decreases due to the physical constraint of a growing uterus, the respiratory center in the brain is stimulated by the hormone progesterone to get you to take slower breaths. Progesterone is released during pregnancy. Although each breath may bring in less air, the air stays in the lungs longer so you extract the oxygen you and your baby need.

Your body also expands your blood volume during pregnancy to make sure your baby is also getting enough oxygen.

How to manage shortness of breath

Shortness of breath can be uncomfortable, but there are ways that you can breathe more comfortably.

Practice good posture

Make sure that you stand up straight with your shoulders back and your head lifted. Visualize a straight line connecting your sternum toward the sky to lift your chest.


Aerobic exercise improves your breathing and lowers your pulse. Make sure that any program you begin is approved by your doctor.

If you haven’t begun practicing already, now’s a good time to start prenatal yoga. Breathing is central to yoga practice, and the extra stretching can improve your posture and give you more room to breathe.

Whatever form of exercise you choose, don’t overdo it! Listen to what your body is telling you.


“Just relax!” While that’s easy for someone who isn’t experiencing shortness of breath to say, it’s also true. The more anxious you become about shallow breathing, the shallower your breathing will become. It’s also important to rest when you need to rest.

Don’t overdo it

Listen to what your body is telling you and rest when you need a break. Now’s not the time to push yourself too hard. It’s important to pay attention to your body’s limits.

The feeling of breathlessness gets better as you approach delivery. As your baby descends in your pelvis, pressure on the diaphragm and lungs is somewhat relieved.

Warning signs of shortness of breath

While it’s good to know nature has a plan for your body, you should look out for warning signs in the unlikely case that your shortness of breath indicates that something’s wrong.


No doubt you already know if you have asthma before you get pregnant. You also may already know that asthma can get worse during pregnancy. Discuss with your doctor if asthma could be making your shortness of breath worse during the third trimester.


In some cases, anemia — insufficient iron in your blood — can cause shortness of breath. Other symptoms of anemia include fatigue, headache, and a bluish tint to your lips and fingertips. To diagnose anemia, your doctor can check your iron levels and may prescribe iron supplements.

Pain or persistent cough

If you feel pain while taking deep breaths, experience fast breathing, or sense an increase in your pulse, contact your doctor immediately. These could be signs you have passed a blood clot to your lung. This is also known as a pulmonary embolism.

Contact your doctor if you have a cough that lasts for more than a few days. You should always contact your doctor or call your local emergency services immediately if you feel chest pain.

What is edema?

Edema is a condition in which excess fluid builds up in your body’s tissues. You’ll notice it most in your feet, ankles, and sometimes, in your hands. The fluid tends to pool in parts of your body most affected by gravity.

Many women experience edema during their pregnancy. For most of these women, warm weather and remaining in one position for any length of time contribute to swelling. Edema is at its lowest in the morning and increases throughout the day.

Report any leg pain to your doctor immediately. Tell your doctor if you notice sudden swelling or puffiness in your face or hands. This can be a sign of preeclampsia.

How can I manage edema?

Here are some strategies that can help you combat edema:

  • Elevate your feet. Sit with your feet propped up whenever possible.
  • Wear support hose. Full pantyhose may not feel good when you’re pregnant, but there are also support knee socks. Choose the size you’d have chosen before you were pregnant. Put them on in the morning before you become swollen.
  • Avoid excessive salt intake. This can lead to fluid retention.
  • Drink plenty of water. Staying hydrated will flush out wastes and help reduce the amount of water you retain.