Third trimester: Physical changes and common discomforts

Third trimester: Physical changes and common discomforts
Here are the main physical changes you’ll notice and the most common discomforts that can develop during the third trimester.


The big day is just around the corner, and you’re filled with anticipation. But you’re also tired and increasingly uncomfortable as your belly gets bigger and heavier. All this is normal: your baby is taking up more space and your body is preparing for the birth.

Here are the main physical changes you’ll notice during the third trimester.

Physical changes

  • At 7 months, the height of your uterus is about 28 cm. At 8 months, it reaches 30 cm, and then 33 cm at 9 months.
  • Throughout the third trimester, you continue to gain weight, putting on about 4 kg (9 lb.).
  • You may develop stretch marks on your stomach, thighs, and breasts. As your skin stretches, it can feel itchy.
  • Colostrum, the fluid produced before the arrival of breast milk, may leak from your breasts.
  • Your blood volume increases, which can result in anemia, a health problem characterized by low iron levels and fatigue.
  • You are more flexible because your ligaments are softening and the joints in your pelvis are loosening.
  • When you lie on your back, the weight of your uterus may block certain blood vessels, which can make you feel dizzy.

Common discomforts

Pregnancy affects a woman’s entire body. The cardiovascular, digestive, respiratory, nervous, reproductive, and urinary systems are all impacted. It’s therefore normal to feel various aches and pains over the next few months.

Below is a list of the most common discomforts experienced in the third trimester. To learn more about a specific ailment, click on its name and consult the fact sheet.

  • Heartburn
  • Nasal congestion and nosebleeds
  • Braxton Hicks contractions
  • Constipation and hemorrhoids
  • Leg cramps
  • Groin pain
  • Fatigue
  • Swelling of the legs and feet
  • Pain and numbness in the hands
  • Frequent urge to urinate
  • Mood swings
  • High blood pressure
  • Insomnia or light sleep
  • Back pain
  • Headaches
  • Vaginal discharge
  • Shortness of breath
  • Varicose veins in the legs
  • Stretch marks

If you’re concerned about any of your symptoms, write them down and discuss them with your health care provider during your next appointment. Don’t hesitate to contact them between appointments or call Info-Santé (811) if your symptoms are worrisome. Some over-the-counter medications can relieve certain discomforts, but it’s important to talk to a doctor or pharmacist before taking any.

Things to keep in mind

  • During the third trimester, you may feel more tired and uncomfortable as your belly gets bigger and heavier.
  • Changes that occur in the third trimester affect your entire body.
  • If you’re concerned about any of your symptoms, discuss them with the health care professional monitoring your pregnancy.

 

Naitre et grandir.com

Scientific review: Roxanne Piché, nursing adviser, Maternal Fetal Medicine Clinic, CHU Sainte-Justine
Research and copywriting: The Naître et grandir team
Updated: June 2019

 

Sources

Please note: Hyperlinks to other websites are not updated regularly, and some may have changed since publication. If a link is no longer valid, use search engines to find the information you’re looking for.

  • Doré, Nicole, and Danielle Le Hénaff. From Tiny Tot to Toddler: A practical guide for parents from pregnancy to age two. Quebec, Institut national de santé publique du Québec, 2019, 776 pp. www.inspq.qc
  • Ladewig, Patricia, et al. Soins infirmiers en périnatalité. 4th ed., Montreal, ERPI, 2010.
  • Larousse médical. Paris, Éditions Larousse.
  • The Society of Obstetricians and Gynaecologists of Canada. Partir du bon pied. Mississauga, Éditions Wiley, 2010, 235 pp.
  • Regan, Lesley. Votre grossesse au jour le jour. 2nd ed., Éditions Hurtubise, 2010.