Yes, Pilates is generally safe and beneficial during pregnancy — and the American College of Obstetricians and Gynecologists (ACOG) specifically recommends exercise during uncomplicated pregnancies for reducing back pain, improving mood, and supporting easier labour. But what is safe changes as your pregnancy progresses, and modifications become essential from the second trimester onward. A blanket “yes” is not enough. You need to know exactly what to do, what to change, and what to stop at each stage.
Key takeaway: Pilates is one of the best forms of exercise during pregnancy because it trains the exact muscles you need for labour and recovery — pelvic floor, deep core, posterior chain — but you must modify by trimester. After 16 weeks, avoid lying on your back. After 28 weeks, reduce range of motion and prioritise birth preparation over performance.
Pilates is generally safe during pregnancy when modified appropriately for each trimester, according to ACOG guidelines. During the first trimester, avoid deep twists and exercises that raise core body temperature excessively. From 16 weeks, avoid lying flat on your back as the supine position can compress the vena cava and reduce blood flow. In the third trimester, switch to modified breathwork and avoid heavy abdominal loading to reduce diastasis recti risk. Safe exercises throughout pregnancy include pelvic floor activation, gentle spinal mobility, supported bridging, and seated upper body work. Sophie Mercer, PMA-certified clinical Pilates instructor, has designed a 6-week second-trimester Pilates protocol with 24 exercises that follow ACOG recommendations for prenatal exercise safety.
What are the benefits of Pilates during pregnancy?
The benefits are not generic “exercise is good for you” platitudes. Pilates specifically targets the systems that pregnancy challenges most. ACOG Committee Opinion 804 (2020) confirms that regular exercise during pregnancy reduces the risk of gestational diabetes, preeclampsia, caesarean delivery, and excessive gestational weight gain. Pilates takes those general benefits further.
Pelvic floor preparation is the most significant advantage. Pilates trains your pelvic floor to both contract and release — and you need both for birth. Most women focus only on Kegels (contraction), but the ability to consciously relax your pelvic floor is what allows your baby to descend through the birth canal. Back pain prevention is the second major benefit. As your bump grows, your centre of gravity shifts forward. Pilates strengthens the posterior chain — glutes, upper back, deep core — to counteract that shift before pain develops.
You also maintain what I call core connection rather than core strength. You are not trying to build a six-pack during pregnancy. You are maintaining the neural pathways between your brain and your deep stabilising muscles so that postpartum recovery happens faster. Women who maintain this connection typically recover core function 40-60% faster. Pilates also improves circulation, reduces lower limb swelling, and builds the body awareness that helps you find effective labour positions.
What’s safe in the first trimester?
If you were practising Pilates before becoming pregnant, most standard exercises remain safe in the first trimester. Your body has not yet changed significantly in terms of mechanics, so your familiar routine can largely continue. The key adjustments are about energy management, not exercise selection.
Reduce intensity on days when nausea or fatigue hits hard. A 15-minute gentle session is better than skipping entirely. Stay well hydrated and avoid overheating — your body’s thermoregulation changes in early pregnancy, and overheating has been associated with neural tube complications. Skip heated studio classes entirely.
This is the ideal time to build pelvic floor awareness. Start with conscious engagement and release cycles: inhale to relax, exhale to gently draw your pelvic floor upward, hold for 3-5 seconds, then fully release. Learning to let go is just as important as learning to hold. Exercises like pelvic tilts, cat-cow on all fours, and side-lying leg work are excellent foundations. If you are new to Pilates, the first trimester is actually a good time to start gently — beginning with these foundational movements before your body changes gives you a movement vocabulary to draw on later.
What changes in the second trimester?
The second trimester brings the single most important modification in pregnancy Pilates: after 16 weeks, avoid exercising on your back. The weight of the growing uterus can compress the inferior vena cava — the major vein returning blood from your lower body to your heart. This vena cava compression can cause dizziness, nausea, and reduced blood flow to your baby. Some women feel symptoms immediately; others do not notice but the compression is still occurring. Do not rely on how you feel — just make the switch.
Replace supine exercises with side-lying, seated, standing, and inclined alternatives. Focus your work on hip stability — the hormone relaxin is increasing joint laxity, making your pelvis less stable — and upper back strength to counteract the forward pull of growing breasts and bump. Standing single-leg balance work, seated resistance band rows, and side-lying clams are particularly valuable.
This is often called the “golden trimester” because many women feel their best. Energy returns, nausea recedes, and you are not yet large enough to feel physically restricted. You can work relatively hard with the right modifications — this is not a time to coast.
What’s appropriate in the third trimester?
The third trimester is about comfort, breath, and birth preparation — not performance. Reduce range of motion across all exercises. Your joints are at their most lax, your balance is significantly shifted, and your diaphragm is progressively compressed by your growing baby.
Exercises should shift toward breathing techniques for labour — practise lateral thoracic breathing (expanding the ribcage sideways) which trains the respiratory pattern you will use during contractions. Pelvic floor release work becomes more important than strengthening. Your pelvic floor needs to lengthen and open during delivery, so practise the full cycle: engage for 5 seconds, then spend 10 seconds consciously softening and releasing. Gentle hip openers and standing balance work round out the programme. Many women feel most comfortable exercising on all fours or side-lying at this stage.
Listen to your body honestly. Some days you will feel capable and energised. Others, a 10-minute breathing session on your side is the right call. Both are valid and beneficial.
Which exercises should you avoid during pregnancy?
Certain movements should be avoided regardless of how you feel. Deep twisting through the abdomen compresses the uterus and is uncomfortable at best, potentially harmful at worst — eliminate these after the first trimester. Full inversions shift blood flow patterns and increase fall risk as your centre of gravity changes. Heavy abdominal work like crunches, roll-ups, or double leg lowers generates excessive intra-abdominal pressure against tissue that is already stretching.
Watch carefully for coning or doming along the linea alba. If you see a ridge forming along the midline during any exercise, that movement is creating too much pressure on tissue that needs to remain intact. Modify immediately or skip it. Also avoid jumping, high-impact movements, and any exercise lying face-down once the bump is visible.
When should you stop exercising and call your doctor?
Know these red flags. Stop immediately and contact your midwife or doctor if you experience vaginal bleeding, regular painful contractions before term, amniotic fluid leakage, persistent dizziness or feeling faint, chest pain, calf pain or swelling (which could indicate a blood clot), or a headache that will not resolve. Also stop if you experience significant pelvic pain or a sensation of pressure or heaviness in your pelvis.
These symptoms require medical assessment, not modifications. Exercise should not resume until you have been explicitly cleared.
Every pregnancy is different, and what works for one woman may not work for another. The full Pregnancy Pilates Protocol provides trimester-specific modifications with exercises designed to support your body through each stage — from pelvic floor preparation in the first trimester to birth positioning work in the third.
This article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before beginning any exercise programme, particularly if you have an injury or medical condition.