A Women’s Health Physio’s Perspective of What to Expect

Being a Pelvic Health Physiotherapist has given me a great deal of insight into the challenges each stage of pregnancy brings. It is a heart-warming and ongoing part of my work to learn about all the different journeys that each woman’s body undergoes.

I have not been pregnant. But I have studied, worked with and am passionate about the pregnancy journey. From my clinical perspective, I have written this blog to outline what you can expect from each different stage of pregnancy. So, if you are currently pregnant, thinking about trying to conceive or even if you’re just curious about what happens during pregnancy – this one’s for you.

Trimester 1

This stage is from 0-12 weeks of pregnancy and is the developmental stage for all your bub’s vital organs and nervous system. Your little human grows from the size of a poppy seed (week 4) to the size of a chicken egg (week 12).

Unfortunately, this is not the most glamorous stage for some mums-to-be. Morning sickness (which really happens at any time of the day), headaches, fatigue and constipation are all fun stops along the way in this stage. This is all a result of the massive hormonal and cardiovascular changes your body undergoes to accommodate for bub. Your heart begins to pump more blood through the body, and quicker, which results in higher cardiac output and heart rate – both which can make you feel slightly more short of breath life’s daily activities.

Your body also has changes to the level of oestrogen and progesterone in your body, and another hormone called relaxin enters the scene. This hormone is what causes your connective tissue and ligaments to relax, allowing for bub’s growth and development as well as allowing your pelvis to widen in preparation for the weeks to come. But relaxin is not specific – it will affect the whole body. This means your joints all become a bit more bendy, and can cause some discomfort, especially around the back and pelvis. Relaxin significantly increases during the 1st trimester, it will peak at the 12th week and then plateau for the rest of your pregnancy. The increased rise in oestrogen from 12 weeks onwards will continue to soften the joints.

Common symptoms:

  • Morning sickness
  • Breast tenderness
  • Nausea
  • Vomiting
  • Fatigue
  • Constipation

Trimester 2

From week 13 to 28, your bub grows to the size of a small pumpkin. By week 13, we recommend you avoid lying onto your back, as bub is now heavy enough to compress or block blood vessels that run by the spine. A short while can be okay, but you may start to feel lightheaded or nauseous if you stay in this position for too long. Side-lying (either side is fine) may be a comfortable alternative.

Your baby’s features begin to develop in the second trimester, and you may start to feel some movement. Your hormone levels should also begin to balance out, reducing the nasty side effects of your first trimester. For some, this may feel like a ‘honeymoon stage’ – enjoy it! It’s a wonderful time to connect with your little human as well as your own amazing body.

Changes to your musculoskeletal system begin around this stage – breast size increases, muscles start to stretch around your belly, joints begin to soften and move more, your spinal curves become more pronounced, and your centre of gravity shifts forward (which is what causes you to develop the stereotypical ‘pregnancy waddle’). You may find you become a little sorer around your pelvis and lower back, as these joints have the biggest amount of change to help accommodate bub’s growth and development. Muscles around the pelvis (such as your glutes, inner thigh muscles, abdominals and paraspinal muscles) increase in their resting tone/tightness to help support the new movement at the joints. You may start to develop some aches and pains in these areas – this is very common and very manageable (more on this below!).

On top of all this, your heart continues to pump faster to accommodate the increase in blood volume. If you didn’t feel short of breath in the first trimester, you may start to feel it a little more in the second.

A quick note on exercise…

Exercise has amazing benefits for both mum and bub, but some conditions in pregnancy have an impact on the kind of exercise you can do. Please speak to your doctor or Women’s Health Physio if you are concerned about exercising during your pregnancy.

Generally, you should not exercise if you have:

  • Significant heart disease
  • Restrictive lung disease
  • Incompetent cervix or cerclage
  • Multiple gestation at risk of premature labour
  • Persistent vaginal bleeding
  • Placenta previa after 26 weeks gestation
  • Premature labour during the current pregnancy
  • Ruptured membranes
  • Pre-eclampsia or pregnancy-induced hypertension
  • Severe anemia

Pelvic Health Pregnancy Assessments

We highly recommend booking an antenatal assessment for any mum-to-be in the second trimester, even if it isn’t your first time in the pregnancy rodeo. Cliché but true – every pregnancy is different. A Women’s Health Physio can help you navigate any bumps along way, as well as advise you on any potential risk factors or considerations regarding birth or the post-natal period.

What we can assess:

  • Pelvic floor function – strength, tone, endurance, coordination, ability to relax (this is important when it comes to pushing the baby out!
  • Urinary and faecal incontinence
  • Pregnancy-related pain – pelvic girdle pain, pubic symphysis dysfunction (SPD), low back pain, upper back pain, wrist pain
  • Activity and exercise modification to keep you moving during pregnancy
  • Abdominal muscle separation
  • Risk evaluation for postnatal complications

Trimester 3

By the third trimester, your little pumpkin has a major growth spurt to the size of a watermelon! Don’t freak out – your body and joints have been preparing to support this. But you may feel the strain that this extra weight puts on your belly and pelvic floor.

By the third trimester, nearly 2 in 3 women will experience urinary leakage. This happens as a result of the additional weight of bub and your uterus on the pelvic floor, which has been slowly increasing over the last 7 months. Your pelvic floor muscles are also in a more stretched position, and may not be able to contract as quickly or strongly to help out when you cough, sneeze or laugh (or when bub decides to land a well-aimed kick to your bladder).

A little tip to help this:

Try to contract your pelvic floor just before you do an activity. We call this movement ‘the Knack’; it’s a useful tool during or after pregnancy to help control any increase in pressure within your abdominal cavity.

With such a significant growth spurt from bub, this will also affect your posture. Bub will start to move down into the pelvis, ready for deliver. This causes a pull/stretch on the pubic bone, and your baby’s head may press against some sensitive nerve endings. This can cause sharp, shooting pain around the groin and vagina – also known as “lightning crotch”. Commonly, women report pain for anywhere up to a minute, and can get this feeling either if they’ve stayed in one position for too long or when bub moves around. It’s very important to keep yourself comfortable and active – but you might need to modify a few things to achieve this.

Taking smaller steps when walking, turning onto your side before getting up out of bed and minimizing uneven loads on the body can be very helpful. Also, when resting: PILLOW SUPPORT! A nice puffy pillow between the knees and ankles as well as one behind your back can keep your hips even and prevent you from rolling in your sleep.

35 Weeks – Nearing Delivery

At 35 weeks, you are probably counting down the days until you meet your newborn (or at least the days until you don’t feel like an ever-growing baby carrier).
This is when we as Pelvic Health Physios will book you in for a birth preparation consultation (we have another blog on this). We help you relax and get your body ready for delivery, whichever method that may be for you. If you have any burning questions or worries you want to address, this is a wonderful opportunity for you to do so and receive professional advice.

Final Notes from Me…

Being pregnant can mean different things along the way for women, but hopefully this blog can help you better understand the process and prepare for some of the many possibilities along the way. Pelvic Health Physios are always here to help, and can be a wonderful source of information on how you can have the best possible outcome for your body.

Liz Johnson
(Pelvic Floor & Musculoskeletal Physiotherapist)
Female Physio Co.


The Royal Australian New Zealand College of Obstetricians and Gynaecologists (RANZCOG). Exercise During Pregnancy. 2020. Report No: C-Obs 62.

Jeffreys RM, Stepanchak W, Lopez B, Hardis J, Clapp JF 3rd. Uterine blood flow during supine rest and exercise after 28 weeks of gestation. BJOG. 2006 Nov;113(11):1239-47. doi: 10.1111/j.1471-0528.2006.01056.x. Epub 2006 Sep 15. PMID: 16978230.

Aldabe D, Ribeiro DC, Milosavljevic S, Dawn Bussey M. Pregnancy-related pelvic girdle pain and its relationship with relaxin levels during pregnancy: a systematic review. Eur Spine J. 2012 Sep;21(9):1769-76. doi: 10.1007/s00586-012-2162-x. Epub 2012 Feb 4. PMID: 22310881; PMCID: PMC3459115.