Your body experiences significant changes during pregnancy, particularly your abdominal muscles, which stretch to make room for your little one.
To help cope with these changes, many moms-to-be follow a regular fitness routine that includes abdominal (aka core) strengthening exercises like planks, pelvic tilts, crunches, and situps.
Although a strong core can help you maintain a neutral spine, reduce muscle fatigue, and minimize back pain, specific exercises, including full situps, may cause more trouble than they’re worth (1).
Read on to learn whether situps are safe and recommended during pregnancy, understand how your abdominal muscles change during pregnancy, and get inspired by some core exercises to add to your routine.
Many moms-to-be worry that certain activities may hurt their baby. However, when it comes to situps, Dr. Vonne Jones, MD, FACOG, says this exercise won’t harm the baby.
“There’s essentially no risk to the baby because the amniotic fluid protects it in the uterus, and the uterus is also protected by an abdominal sheet, which is called the abdominal peritoneum,” she says.
So, if there’s no risk to the baby, why the hesitation to include situps in a pregnancy workout?
“There is some risk of increasing the outward pressure on the abs and the downward pressure on the pelvic floor with these exercises,” says Helene Darmanin PT, DPT, CSCS.
Plus, putting pressure on the inferior vena cava can cause problems. “Being supine and rounding the spine to perform a crunch or situp can increase pressure on the inferior vena cava, the main vein that returns blood to the heart from the lower body,” says Darmanin.
Darmanin says the body can interpret the pressure as high blood pressure and cause a sudden compensatory drop in blood pressure, which could decrease blood flow to your heart, brain, and fetus.
However, she points out that this effect is most likely symptomatic, and you could roll onto your side to alleviate any dizziness or lightheadedness.
Situps are not a safety risk for your baby, but they may contribute to diastasis recti or uterine prolapse. Plus, it’s recommended that you avoid lying on your back for extended periods of time after the first trimester.
If situps are not a risk to the baby, why should you consider avoiding them during pregnancy?
“Situps work the rectus abdominis muscles, which requires a ‘pushing out’ of your abdominal muscles during these movement patterns,” says Natalie Niemczyk, DPT, CSCS.
As you progress through your pregnancy, Niemczyk says you want to avoid these particular movements due to the risk of diastasis recti abdominis (DRA). This is a separation of the two sides of the rectus abdominis muscle, and it runs vertically up the front of your stomach.
Sometimes called “mummy tummy,” diastasis recti can appear as a bulge down the middle of the abdomen, separating the right side from the left, when exercising.
DRA can cause symptoms, including:
- low back pain
- pelvic floor dysfunction
- poor posture
- pelvic pain
- hip pain
- a feeling of weakness or disconnection through the trunk
- a doming of the abdominals during activity
- belly “pooching” or still appearing pregnant
One study found that 33% of first-time moms had diastasis recti at 21 weeks gestation. This number jumped to 60% at 6 weeks postpartum but went down to 45.4% at 6 months and 32.6% at 12 months postpartum (
An OB-GYN, physical therapist trained in postpartum care, or other medical professional can diagnose this condition. In general, a diagnosis is made if the separation is wider than 2 centimeters, although some experts use 1.5 centimeters as the minimum (
Diastasis is a separation of the two rectus abdominis muscles. Full situps can contribute to or worsen diastasis recti.
When you’re pregnant, the increased size of your pelvic contents creates an increase in outward pressure, which Darmanin says goes forward through the abdominal wall. Yet, some of it also goes upward, and the diaphragm changes shape to accommodate this change.
“This forward pressure causes the abdominal muscles to stretch, including the linea alba, which is the line of connective tissue between the two halves of the rectus abdominis,” says Darmanin.
Although you can’t prevent your abs from stretching, you can incorporate exercises that focus on your deeper abdominal muscles, which Niemczyk says support your spine.
She also suggests exercises that focus on the pelvic floor muscles, as they help maintain continence, provide support for your pelvic organs and growing baby, and assist with labor, delivery, and recovery.
That’s why Niemczyk says to focus on your transverse abdominis and pelvic floor musculature, which all help to stabilize your belly and spine during pregnancy.
“The transverse abdominis wrap around your body like a corset, and the pelvic floor supports your baby from below. You want to focus on abdominal drawing-in techniques and bracing your abdominals to help strengthen this musculature, as these muscles help to support you most during pregnancy,” she says.
As your pregnancy progresses, your abdominal muscles stretch. This is normal and typically resolves itself after pregnancy. However, if the stretching becomes excessive, you can develop diastasis recti, which is a separation of the rectus abdominis muscles.
To reduce the risk of developing or worsening diastasis recti, aim to include exercises that focus on strengthening your transversus abdominis. This muscle runs horizontally underneath the rectus abdominis or “six-pack.” It plays a critical role in stabilizing your pelvis.
Here are six exercises you can incorporate into a prenatal fitness routine.
Remember to talk with your OB-GYN before starting any exercises or regimens. Also, some of the exercises below may not be safe during all stages of pregnancy or require modifications. Again, it’s best to consult your doctor.
Bear plank is a great alternative to the traditional plank during pregnancy. It will help you engage your core, arm, and leg muscles while minimizing the pressure on your abdominal wall.
- Start on all fours with a neutral spine and your toes tucked.
- Engage your core muscles to draw your navel to your spine, pressing into the balls of your feet to lift your knees off of the ground.
- Hold this position for 3–5 deep breaths, then release back down to the starting position.
Darmanin says exercises on your hands and knees are great for the core during pregnancy if you can still draw your abs up into your spine and don’t see your belly coning, doming, or tenting.
- Get on all fours with your back flat, hands beneath your shoulders, and your knees under your hips.
- Contract your core muscles and extend your left leg behind you while simultaneously extending your right arm in front.
- Hold in this position. After a few seconds, slowly return to the starting position.
- Repeat on the other side.
- Do 2 sets of 10 reps on each side.
- Start on the floor on all fours with your spine neutral, wrists under your shoulders, and your knees under your hips. Curl your toes under.
- Contract your core muscles.
- Take a deep breath in, and on the exhale, get ready to move into Cat pose.
- Round your spine toward the ceiling as your head and tailbone move closer to each other — gaze toward your navel.
- Hold for 2 seconds.
- Pass back through a neutral spine as you release Cat pose. Then arch your back and lift your head and tailbone toward the ceiling to transition to Cow pose.
- Hold for 2 seconds.
- Repeat for 30–60 seconds.
Side plank on knees
- Sit on your right hip with your knees bent, off to the left side. Keep your knees in line with your hips and your feet behind you.
- Bend your right elbow and place your forearm on the ground. Reach your left arm up to the ceiling, or place it on the floor in front of you for balance. Inhale.
- Drawing your belly button to your spine, exhale to engage your right obliques and lift your hips off of the floor, making a straight line through your body from your knees to your head.
- Hold for a full inhale and exhale, and then lower to the starting position.
- Do 6–8 reps on each side.
This exercise is best performed in the first trimester. When your healthcare professional says you should no longer lie supine on your back, forego this exercise.
- Lie down on an exercise mat with your knees bent and arms at your sides. Inhale.
- Exhale to lightly tilt your hips toward your belly button without pushing into your feet or lifting your glutes off of the floor. Use your obliques to perform the movement, imagining drawing your hips closer to your ribs.
- Inhale to release back to the starting position.
- Do 2 sets of 10–12 reps.
Focusing on the transverse abdominis muscle and performing core exercises other than full situps might be the way to go during pregnancy. Moves like the Bird Dog, plank, and pelvic tilt all activate the critical abdominal muscles.
Overall, it’s safe to continue exercising if your pregnancy is normal (4).
Including exercises to strengthen your abdominal muscles should be part of a prenatal fitness routine. Although traditional situps don’t pose a risk to your baby, they may contribute to diastasis recti.
If you have questions or concerns, talk to your doctor during an early prenatal visit. They can also help you decide which activities are safe to continue and which ones to avoid until the postpartum period.
Adapting your core routine just a little bit will yield big results when it comes time to have your baby and beyond.