A peanut ball is a peanut-shaped inflatable ball used primarily during labor to open the pelvis and help the baby descend. It’s especially useful if you have an epidural and can’t move freely. In clinical trials, women who used a peanut ball during labor cut their C-section rate roughly in half compared to those who didn’t, dropping from 21% to 10% in one study. Here’s how to use one effectively, whether you’re preparing for labor or using it for exercise and therapy.
Why Peanut Balls Work During Labor
The hourglass shape of a peanut ball keeps your legs apart and your pelvis in an open position while you rest in bed. This wider pelvic opening gives the baby more room to rotate and move downward through the birth canal. A standard round birth ball does the same thing when you sit upright on it, but the peanut shape stays stable between your legs while you’re lying on your side, which is what makes it so valuable for women with epidurals who can’t stand or squat.
The numbers are compelling. A randomized controlled trial published in the Journal of Perinatal Education found that peanut ball use shortened the first stage of labor by 29 minutes and the pushing stage by 11 minutes. The C-section rate was cut by more than half. A separate study of 164 women with epidurals found a similar 50% reduction in cesarean births. Importantly, the benefit wasn’t just from the ball itself. Frequent position changes while using it were the strongest predictor of shorter labor across both stages.
Choosing the Right Size
Peanut balls come in four sizes, and using the wrong one means your pelvis won’t open to its full potential. The sizing is based on your height:
- 40 cm: For women under 5’3″
- 50 cm: The most common size, for women between 5’3″ and 5’6″
- 60 cm: For women 5’7″ or taller, or those carrying extra weight
- 70 cm: Used only for sitting or straddling positions, not for placing between the legs
If you’re between sizes, going slightly larger is generally better, since a ball that’s too small won’t create enough pelvic opening. Many hospitals stock peanut balls, but sizes may be limited, so it’s worth bringing your own if you have a preference.
The Four Main Labor Positions
Clinical protocols use four peanut ball positions during labor: side-lying, tuck, semi-sitting, and sitting. You can start using the ball once you’re at least 4 centimeters dilated, and it stays in play until you’re ready to push.
Side-Lying
This is the most common and most studied position. Lie on your side and place the peanut ball between your legs so that your top leg rests over the center of the ball and your bottom leg stays below it. Your top knee should be bent and elevated, opening your pelvis wide. The ball’s narrow middle keeps it from rolling away, which is why it works better than a pillow or regular ball in this position. This is the go-to position if you have an epidural and need to rest while still encouraging the baby to descend.
Tuck Position
From the side-lying position, draw both knees up toward your chest with the peanut ball still between your thighs. This creates an even deeper pelvic opening and can help a baby who is slow to rotate. It’s more intense on the hips, so you may not want to hold it as long as the standard side-lying position.
Semi-Sitting
Raise the head of the bed to about 45 degrees. Place the peanut ball between your knees while your feet rest flat on the mattress. This uses gravity to help the baby move down while still keeping your pelvis open. It’s a good option if you want to be more upright but aren’t comfortable fully sitting.
Sitting and Straddling
If you’re mobile enough, you can straddle the peanut ball on the bed or a chair the same way you’d sit on a regular birth ball. The elongated shape gives more front-to-back stability so you’re less likely to roll off. This position is typically used with the larger 70 cm ball. It allows gentle rocking and hip circles that encourage the baby to settle deeper into the pelvis.
How Often to Switch Positions
Position changes matter as much as the ball itself. Clinical protocols call for repositioning at minimum every one to two hours. In one study, the frequency of position changes was a stronger predictor of shorter labor than just having the peanut ball in place. For side-lying, this means alternating which side you lie on every one to two hours. You can also rotate between the different positions listed above to keep the pelvis moving and give the baby new angles to work with.
If your labor nurse or midwife suggests a specific position based on how the baby is oriented, follow that guidance. The position that works best can change as labor progresses and the baby moves through the pelvis.
Inflation and Care
Peanut balls require surprisingly little air pressure, only about 2 PSI. An electric pump designed for exercise balls will fill it properly without overinflating. You want the ball firm enough to hold its shape under your leg weight but with a slight give when you press into it. If it’s so soft that your legs sink to the mattress, add more air. If it feels rock-hard and uncomfortable against your inner thighs, release a little.
Before each use, check the surface for any cuts, weak spots, or loose seams. Keep the ball away from sharp objects, IV poles, or anything that could puncture it. If you’re using it at home before heading to the hospital, stick to smooth indoor surfaces.
Using a Peanut Ball for Exercise and Therapy
Outside of labor, peanut balls are popular in pediatric physical therapy and general core strengthening. The peanut shape is more stable than a round exercise ball, making it a better choice for children or anyone working on balance and coordination. A few effective exercises:
- Seated bouncing: Sit on the ball with both feet planted on the ground and bounce gently. This builds core stability and provides calming sensory input for kids who need movement breaks.
- Tummy roll: Drape yourself forward over the ball on your stomach and walk your hands out along the floor. This strengthens the shoulders, arms, and core. For children, placing toys ahead of them gives them motivation to reach forward.
- Wall press: Place the ball against a wall, lie on your back, and push against the ball with your feet. This builds leg strength and provides deep pressure input through the joints.
- Balance challenge: Lie on your back and try to hold the peanut ball up in the air with your feet, engaging your core and legs simultaneously.
For all of these exercises, the peanut ball’s stability is the key advantage. It won’t roll sideways the way a round ball does, so you can focus on the movement rather than fighting to stay on top. Children should always have adult supervision, especially when lying on their stomachs over the ball, since a shift in weight can send them forward quickly.