A woman’s body changes during pregnancy in some impressive and far-reaching ways. Sometimes, it can be helpful to understand what’s going as you experience it. Or if you’re struggling with some of these changes postpartum, learning the details of what your body went through can be key in unraveling the remaining mysteries.
How does breathing change with pregnancy
The diaphragm is a large muscle that sits under the lungs and at the bottom of the rib cage. When it contracts, it moves downward, allowing the lungs more space to expand and fill with air. When it relaxes, it drifts back upwards, helping to expel the air back out of the lungs through the nose or mouth.

As a woman’s body changes during pregnancy, that gorgeous babe starts to take up more and more the space below the diaphragm. Because of this, it grows increasingly difficult to move the diaphragm downward. Have you ever felt like you couldn’t get a good, deep breath while pregnant? This is why.
Lots of women compensate for this by using the muscles in the neck and shoulders to create more space upward, instead. This does help to get more air into the lungs, but it can also contribute to pain or tingling in the hands. As the neck and shoulder muscles get tighter from their increased effort, they can put pressure on the nerves that supply the hands and contribute to these symptoms.
What happens to your abs as your body changes during pregnancy
It comes as a surprise to no one that the abs of a pregnant woman have to endure quite a bit of stretching. Because a muscle that is too long cannot contract well, the woman loses some degree of function. Depending on the particular woman and stage of pregnancy, this loss of function can vary from minimal to significant, and it can have far-reaching effects throughout the body.
How the abs impact posture

As the abs stretch and make room for the baby to grow in the front of the mother, the mother’s pelvis tilts forward. This spreads the distance between her ribs and pelvis and causes her center of gravity to shift forward. To keep that baby from actually pulling her over, she has to increase the arch in her lower back, and her back muscles tighten with this increased demand.
In her upper body, her ribs spread upward and outward to allow room for the growing baby. This contributes to further stretching of the abs. Additionally, a pregnant woman often rounds her shoulders and upper back forward to compensate for the added curve in her low back. In doing this, she brings her eyes back on the horizontal and balances her upper body over her growing belly. The rounding of the upper back is further compounded by increasing breast tissue and the postpartum effects of breastfeeding and childcare.
Why abs and glutes are like peas and carrots

As if all of this wasn’t enough, one of the many jobs of the abs is to stabilize the pelvis by providing an upward force in the front. Counteracting this is the gluteus maximus—the largest muscle in the human body. It balances out the upward force of the abs by pulling down from the back.
As the abs stretch out, they no longer provide the same stability to the pelvis, and therefore, glute max puts in less work as well. Decreased glute strength goes hand-in-hand with decreased ab strength, and vice versa. As a result, most women compensate by stabilizing the pelvis with their back muscles and hip flexors, instead. Just like the postural changes, theses compensations often stick around even after the baby is born.
What happens to the pelvic floor during pregnancy
No discussion of how the body changes during pregnancy would be complete without mentioning the pelvic floor. The pelvic floor muscles are the ones that close the bottom of the pelvis. They play important roles in peeing, pooping, sex, and, of course, childbirth.
It’s easy to think that most pelvic floor changes occur with delivery, and lots of them do. But even during pregnancy or with c-section deliveries, there are significant changes that occur to the pelvic floor. It has to soften and stretch to prepare for childbirth, and it does this regardless of how the baby actually ends up being born.

It also has to support the weight of the growing baby and uterus on top of it. In combination with the stretching that occurs, this added weight is a reason why leaking can be so common during pregnancy. Not only is there more pressure down on it, but as it stretches, it has less ability to resist the pressure.
How the pelvic floor impacts core stability
Under non-pregnant conditions, the pelvic floor has an important role in providing stability to the spine by generating an upward force. When that big, beautiful baby is in the way, it acts as a stress shield to the pelvic floor. The baby creates stability by simply being present, and this decreases the demand on the pelvic floor.
And lastly, the presence of the baby interrupts the natural coordination of the diaphragm with the pelvic floor. Normally, they should both move up and down together, but with the baby there, this coordination is lost. Because the diaphragm and pelvic floor work with the abs to stabilize the body from its deepest aspect, the disruption of these three muscle groups has a significant impact on overall core stabilty.
All of these reasons generally combine to leave mothers with weaker pelvic floors after pregnancy and delivery. For some women, this strength will gradually return postpartum, but for most, a little active effort in that direction can go a long way.
Don’t forget the hormones!
Hormones are the little drivers for most of the pregnancy changes discussed here. They tell our bodies to how to adapt, accommodate, and grow tiny humans. They are incredible, really.
But included in all of the amazing responsibilities of hormones is the creation of ligament laxity. This is helpful because it allows a woman’s body to change with relative ease during pregnancy. It also allows women to be more supple and pliable for delivery.
On the other hand, this laxity can contribute to greater difficulty maintaining good posture and alignment. And it can create joints that are so lax that they lose a certain degree of function.
Finally, it’s important to understand that ligament laxity doesn’t immediately resolve after birth. If a woman chooses to breastfeed, a lot of these hormones continue for the duration of breastfeeding. This isn’t a reason not to breastfeed, but it is factor to take into consideration.
So, what to do about all of these body changes during pregnancy?
If you need more details on how your body changes during pregnancy or what to do about it, I would highly recommend finding a pelvic floor physical therapist near you. You can see one while you’re pregnant to learn how to have a smoother pregnancy AND recovery. And you’ll have far more time for this sort of thing BEFORE babe arrives.
But if your baby is already here, don’t worry. Despite everything you might see in the media, recovery from pregnancy isn’t the sort of thing that needs to happen on a timeline. You can see incredible results even decades after becoming a mother by addressing the components of core stability that are behind all of the typical complaints: diastasis recti (ab separation), postpartum incontinence, pelvic organ prolapse, painful sex, and back pain.
My first recommendation for anyone postpartum is still the same. If you can, get in to see a pelvic floor physical therapist. There’s a lot they can teach you about movement strategies and about how your particular body changed with pregnancy. One-on-one advice that’s customized to your specific needs is truly priceless.
If, for any reason, a pelvic floor physical therapist isn’t available to you, the Mama Made Strong Program is an online next-best-option. Rather than walk you through a specific exercise routine, it uses exercise, video, and detailed instruction to teach you to make the changes that will have the biggest impact on you, in particular. Because you customize it to your needs, you gain a better understanding of your body and are more likely to find success with whatever your goals might be.
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