A pregnancy ball (also called a birthing ball) is one of the simplest tools for relieving back pain, opening your pelvis, and staying comfortable from the second trimester through labor and beyond. You can start using one at any stage of pregnancy, though the biggest payoff comes from around 32 weeks onward, when targeted movements help ease aches and encourage your baby into a good position for birth.
Choosing the Right Size
The ball needs to be large enough that your knees sit about 10 centimeters (4 inches) lower than your hips when you’re seated. The NHS recommends a 65 cm ball if you’re up to 5 feet 8 inches tall and a 75 cm ball if you’re taller than that. If you’re under about 5 feet 4 inches, a 55 cm ball is a better fit. When you sit on a properly sized ball, your thighs should slope gently downward and your feet should rest flat on the floor.
Look for a ball labeled “anti-burst” or “burst-resistant.” These are designed to deflate slowly if punctured rather than popping. Most quality options support at least 300 pounds. A standard gym ball and a birthing ball are functionally the same product as long as the gym ball has that anti-burst rating.
How Sitting on the Ball Helps
Simply replacing your desk chair or couch with a pregnancy ball changes the way your body distributes weight. Sitting on the ball engages your core muscles to keep you balanced, which strengthens the lower back and abdominal muscles you’ll rely on during labor and postpartum recovery. It also takes pressure off the nerve pathways around your lower spine and pelvic joints, which is why many people notice immediate relief from low back and hip pain the first time they sit down.
The unstable surface also keeps your pelvis mobile. Small, natural movements while sitting help widen and flex the pelvic bones and joints, making more room for your baby to descend when the time comes. And because the ball encourages an upright, slightly forward-leaning posture, gravity works in your favor to keep the baby’s heaviest part (the back of the head) tilting toward your belly, which is the ideal position for delivery.
Exercises During Pregnancy
You don’t need a complicated routine. A few key movements, done for 10 to 20 minutes at a time, cover the essentials.
- Gentle bouncing. Sit on the ball with your feet hip-width apart and bounce lightly. This rhythmic motion loosens the lower back and pelvis without impact. It also builds familiarity with the ball so you feel confident using it during labor.
- Hip circles. While seated, slowly rotate your hips in wide circles, as if stirring a pot with your pelvis. Do several rotations in each direction. This opens the pelvic joints and can help encourage a baby who’s slightly off-center to rotate into a better position.
- Figure eights. Trace a figure-eight pattern with your hips. This variation targets slightly different angles of the pelvis than circles alone and feels especially good when your lower back is tight.
- Pelvic tilts. Rock your hips forward and backward while seated. Tilting forward arches your lower back gently; tilting backward flattens it. Alternating between the two keeps the lumbar spine mobile and relieves stiffness from sitting or standing in one position too long.
From around 32 weeks, these exercises do double duty. They still relieve aches, but they also help your baby settle head-down and face your spine (the anterior position), which is the most straightforward position for vaginal delivery.
Using the Ball During Labor
During the first stage of labor, staying upright and mobile can help contractions become more effective and may shorten that stage. The ball gives you a way to stay active without exhausting yourself. Gravity helps your baby descend, and the gentle movement provides a form of non-painful sensory input that can reduce how intensely you perceive contraction pain, a concept researchers call the gate control theory of pain.
Positions to Try
Seated bouncing and swaying. Sit on the ball and rock your hips or bounce gently through contractions. Many people find the rhythmic motion easier to manage than sitting still on a bed.
Leaning forward over the ball. Kneel on the floor and drape your upper body over the ball, hugging it. This position takes pressure off your back and is especially helpful if you’re experiencing back labor. It also gives a partner easy access to rub your lower back or apply counter-pressure.
Standing lean. Place the ball on a bed or counter and lean into it while standing. This keeps you upright, which uses gravity to your advantage, while giving your arms and upper body a rest between contractions.
All fours with support. Get on your hands and knees and rest your forearms on the ball. You can rock forward and back or sway side to side. This opens the pelvis and is one of the most effective positions for relieving back pain during labor.
There’s no single “correct” position. The goal is to find what feels comfortable in the moment and to keep your pelvis moving. Many people cycle through several positions as labor progresses.
After Delivery
The ball doesn’t have to go into storage once the baby arrives. Sitting on it while holding your newborn lets you bounce and sway gently, which many babies find soothing. At the same time, the subtle core engagement from balancing on the ball helps rebuild the abdominal and pelvic floor muscles that stretched during pregnancy. You can progress back to hip circles and pelvic tilts as you feel ready, turning everyday soothing time into light postpartum rehab.
Safety Tips
Use the ball on a non-slip surface. Carpet or a yoga mat on hard flooring works well. Avoid tile or polished wood where the ball could slide out from under you. Keep shoes or bare feet (not socks) on the floor for grip.
Inflate the ball until it’s firm but still has a little give when you sit. An overinflated ball is harder to balance on, while an underinflated one won’t support your pelvis at the right height. Most balls come with a hand pump and a guideline for diameter; measure with a tape measure if you’re unsure.
Some situations call for caution. If you’re carrying multiples, your baby is in a position that rules out vaginal delivery, or you have a pregnancy complication that requires restricted movement or close monitoring, check with your care team before using the ball. For uncomplicated pregnancies, it’s a low-risk tool you can use daily from early pregnancy onward.