Upper back pain during pregnancy is common, and it usually comes down to a combination of hormonal changes, a shifting center of gravity, and physical expansion of your rib cage. While lower back pain gets most of the attention, the thoracic spine (the area between your shoulder blades and the base of your neck) takes on significant new stress as pregnancy progresses. Most of the time this pain is muscular and manageable, but in some cases it can signal something that needs medical attention.
How Your Posture Changes as Your Belly Grows
The most straightforward cause of upper back pain in pregnancy is the way your body repositions itself to accommodate a growing baby. As your belly expands, your center of gravity shifts forward. To keep from tipping over, your pelvis tilts forward and the curve in your lower back deepens. This has a domino effect: to compensate, the upper back rounds more, increasing what’s called thoracic kyphosis. One study tracking spinal changes across trimesters found a measurable increase in upper back curvature as early as the second trimester.
That increased rounding stretches and fatigues the muscles between your shoulder blades. These muscles are working overtime to keep you upright, and by the end of the day they’re often sore, tight, or burning. If you spend long hours sitting at a desk or looking down at a phone, this forward-hunched position compounds the problem.
Hormones Loosen More Than Your Pelvis
Your body produces a hormone called relaxin during pregnancy, and its job is to loosen the ligaments in your pelvis so your body can eventually deliver a baby. The problem is that relaxin doesn’t target one area exclusively. It loosens muscles and ligaments throughout your back and abdomen too, which reduces the stability of your spine overall. When the joints and ligaments in your upper back become lax, the surrounding muscles have to pick up the slack. That extra demand on muscles that are already strained by postural changes is a recipe for pain and stiffness.
Your Rib Cage Physically Expands
This one surprises many people: your rib cage expands by an average of 2 to 3 inches in circumference during pregnancy. As the uterus grows, it pushes the diaphragm upward, and the ribs flare outward to make room. This expansion pulls on the joints where your ribs connect to your spine, creating stiffness and aching across the mid and upper back. It can also make deep breathing feel harder, since the normal downward movement of the diaphragm is restricted by the crowded abdominal cavity and the added stiffness in your ribs and side body.
Rib flare tends to become more noticeable in the third trimester and can make it uncomfortable to sit for long periods or lie on your back. Some women feel the discomfort most along the sides of the rib cage, while others notice it right between the shoulder blades where the ribs attach to the thoracic spine.
Breast Changes Add to the Load
Breast tissue increases significantly during pregnancy, sometimes by several cup sizes. That added weight on the front of your chest pulls the shoulders forward and increases the rounding of the upper back. The muscles in your upper back and between your shoulder blades are essentially fighting gravity all day to counterbalance this extra load. If you weren’t accustomed to carrying much weight in your chest before pregnancy, this shift can be particularly noticeable.
What You Can Do for Relief
Stretch Your Upper Back
Gentle stretching can relieve the tension that builds between your shoulder blades. A seated torso rotation is one option recommended by the Mayo Clinic: sit on the floor with your legs crossed, hold your right foot with your left hand, place your right hand behind you, and slowly twist your upper body to the right. Hold for several seconds, then repeat on the other side. If sitting on the floor is uncomfortable, use a mat or a towel, or sit in a chair.
Opening the chest is equally important. Doorway stretches, where you place your forearms on either side of a door frame and gently lean forward, can counteract the forward-rounding posture that strains the upper back. Cat-cow stretches on all fours also help mobilize the thoracic spine. Aim for a few minutes of stretching multiple times a day rather than one long session.
Adjust Your Workspace
If you work at a desk, small setup changes make a real difference. Position your monitor at arm’s length with the top of the screen at or just below eye level so you’re not looking down or craning your neck forward. Your feet should rest flat on the floor (or on a footrest) with your thighs roughly parallel to the ground. A chair with adjustable seat depth is helpful since your comfort position will change as your belly grows. Armrests take strain off your shoulders and upper back by supporting the weight of your arms.
Take breaks every 30 to 45 minutes to stand, walk around, and roll your shoulders. Even brief movement interrupts the cycle of static muscle fatigue that drives upper back pain.
Support Yourself While Sleeping
Side sleeping is generally the go-to position as pregnancy progresses, but without support it can leave your upper body sagging and your spine out of alignment. Placing a pillow between your knees helps align the spine and pelvis, and a second pillow hugged to your chest or tucked under your belly keeps your shoulders from collapsing forward. Some women find a full-length body pillow does the job of multiple pillows at once. The goal is to keep your spine as neutral as possible so you’re not waking up with stiffness that compounds throughout the day.
When Upper Back Pain May Signal Something Else
Most pregnancy-related upper back pain is musculoskeletal and, while annoying, not dangerous. But there are a couple of situations where upper back pain can point to something more serious.
Preeclampsia, a condition involving high blood pressure during pregnancy, can cause liver swelling that produces severe pain in the upper abdomen that radiates to the right side of the back. This pain tends to be constant and intense rather than the dull ache of muscle fatigue. If you’re experiencing this kind of sharp, unrelenting pain along with headaches, vision changes, or sudden swelling in your face or hands, that combination warrants immediate medical evaluation.
Gallstones are also more common during pregnancy due to hormonal changes that slow gallbladder emptying. The classic symptom is pain between the shoulder blades, often accompanied by nausea and intense discomfort in the upper right abdomen after eating fatty foods. This type of pain comes in waves and is distinctly different from the steady, posture-related ache most pregnant women experience.
The key distinction is pattern. Musculoskeletal upper back pain tends to worsen with activity and improve with rest, stretching, or position changes. Pain that is sudden, severe, one-sided, or accompanied by other symptoms like high blood pressure, fever, or vomiting is a different category entirely.