What Physically Happens to my Body During Pregnancy?

By Tash Barry – Physiotherapist 


Pregnancy is an amazing experience that results in many changes to a woman’s body. These changes, both seen and unseen, are crucial in allowing a baby to grow. As a result however, pregnant women can begin to experience discomfort, which can lead to pain or injury.  Although they are more likely in the third trimester, they can present at any time. Pregnant women commonly seek physiotherapy treatment for:

  • Upper back or rib pain
  • Lower back pain
  • Sciatica
  • Pelvic girdle pain
  • Neck pain or headaches
  • Wrist pain
  • De’Quervains (thumb pain)
  • Pelvic floor dysfunction
  • Hip pain

The postural and biomechanical changes are the ones much easier to spot, and include:

  • A growing uterus which means extra weight in your tummy and your pelvis tipping forward. This also increase the curve in your lower back, known as lordosis.
  • Increase in size and fullness of breasts, often leading to an increased forward curve in your upper back.
  • Rising of internal organs and the uterus, and ribs flaring out which increases the diameter of your chest by up to 10-15cm!
  • Increase in body weight. Normal weight gain is between 11.5kg and 16kg, however this can be influenced for example by gestational diabetes.
  • An altered centre of gravity, affecting your balance

The not so seen changes include altered levels of Relaxin, Oestrogen and Progesterone. Ligaments are made up of connective tissue, which is made up of collagen fibres. Changes in hormones change how collagen is metabolised, resulting in increased connective tissue extensibility. In other words, it helps loosen ligaments allowing your body to grow.


  • The pelvis is made up of three joints (right and left sacroiliac and pubic symphysis) which are held together by many ligaments. These ligaments have increased tension and extensibility, as early as 10 weeks and can increase by up to 7mm!
  • The most superficial abdominal muscle, the rectus abdominus, is held together by connective tissue. This can separate throughout your pregnancy when your baby and uterus grow and the muscle elongates, resulting in a condition known as Rectus Abdominus Diastasis (RAD). This condition is normal during pregnancy, however, it may require treatment if the separation does not reduce once you have had your baby. A six-week postnatal check-up will screen for this.
  • The ligaments around the wrist and thumb can loosen, resulting in Carpal Tunnel Syndrome De Quervain’s.


The changes that are happening around your joints, muscles and ligaments alter the normal feedback mechanism (neuromuscular control). As a result, this can lead to reduced or poor muscle recruitment, further contributing to a reduction in tension. Studies have shown that the load on the hip joints in standing is x2.8 normal for a pregnant woman, in other words you must work a lot harder to do what you used to do!

There are also changes in your blood volume and to a lesser extent your heart rate, which are profound, and by 8 weeks gestation your cardiac output will have increased by 20% already! Your total cardiac output can increase by up to 40% during pregnancy, and your total blood volume by 45%.

In addition to the above, changes in mood, increase in fluid retention, fatigue/tiredness, altered walking patterns, change in work or daily activities, change in exercise/sport type and frequency, increase in oxygen demand on the body, fluid retention, and previous injuries also contribute to an altered load and/or aches and pains.


In summary

Remember, pregnancy is nothing short of amazing! Although these changes result in an increased mechanical stress on your body, they are normal and necessary to allow for your body and baby to grow. They do not always lead to aches or pains, however it is common and we’re here to help.

To prevent developing any injuries, we recommend wearing a maternity bra with good support and completing daily spinal mobility exercises including the cat/cow stretch, or book openings to reduce or prevent any spinal discomfort. We also recommend regular exercise (you can see our blog post on this for further information), including daily pelvic floor exercises.

For assessment and management of pregnancy related conditions, or tips on how to exercise safely under a health professionals’ guidance we recommend you see one of our physiotherapists for advice. We also run pregnancy and postnatal classes led by our physiotherapists, where you can exercise in a safe environment and target core strength, pelvic stability, spine mobility and balance.

Our physiotherapists are highly trained in managing Pregnancy-Related musculoskeletal injuries and can guide you to managing and maintaining an optimum level of health during your pregnancy. Get in touch with us today.


Read our Insight on Exercising During Pregnancy!







Higher Function logo
Higher Function Team reception@higherfunction.com.au
Share this insight

Subscribe to our insights.

Stay up to date with what’s new at our practice and the latest scientific research delivered straight to your inbox.

Thanks! Keep an eye on your inbox for updates.

touch icon

Schedule your next visit

Our online booking system allows you to book from a range of services and classes provided through Higher Function. BOOK NOW →
calendar icon

Upcoming classes

All the classes you know and love. We have classes for all levels – taught by physiotherapists and exercise physiologists. VIEW TIMETABLE →
rebates referrals icon

Referrals & rebates

You do not need a GP referral to see us. We are Primary HealthCare Providers and we are registered with AHPRA/ Medicare. LEARN MORE →