Leaking During Pregnancy: Why It Happens and What You Can Do

Nobody warns you about a lot of things in pregnancy. The ribs. The heartburn at 2am. The fact that sneezing becomes something you brace for.

That last one — bladder leaking when you sneeze, cough, laugh, or move quickly — is one of the more common pregnancy surprises, and one of the least talked about. Around four in ten pregnant women experience it. If it's happened to you, you're not alone.

What causes leaking during pregnancy?

Stress urinary incontinence (SUI) is the involuntary leaking of urine when abdominal pressure increases suddenly. Sneezing, coughing, jumping, lifting — any activity that creates a sudden spike in pressure through the abdomen can trigger it.

It's the most common type of bladder leaking in pregnancy, making up around 63% of cases.

Why pregnancy makes this more likely

Two things are happening at once during pregnancy: hormonal changes and mechanical load. Neither is a problem in isolation — they're part of a normal pregnancy — but together they put the pelvic floor under more pressure than usual.

Hormonal changes

Early in pregnancy, the body produces a hormone called relaxin. Relaxin is understood to soften connective tissue and ligaments throughout the body as part of preparing for birth — and the connective tissue that supports the pelvic floor, bladder, and urethra (the tube urine passes through) is likely affected by this process, reducing the structural support these tissues normally provide.

At the same time, progesterone increases throughout pregnancy. Progesterone relaxes smooth muscle — including the muscle in the bladder wall and the urethral sphincter. The sphincter is what keeps the urethra closed when you need it to be. When it's less able to hold tension under load, leaking becomes more likely.

Mechanical load

The pelvic floor is a group of muscles at the base of the pelvis that support the bladder, uterus, and bowel. As the uterus grows — particularly in the second and third trimester — it places increasing downward pressure on these muscles. By the time you're in the third trimester, that's a significant load on a system that's already working with softened connective tissue and a more relaxed sphincter.

How common is leaking during pregnancy?

A 2021 systematic review of over 88,000 pregnant women found:

• 9% reported bladder leaking in the first trimester

• 19% in the second trimester

• 34% in the third trimester

So if you've made it to the third trimester without leaking, you're doing well statistically. And if you have been leaking, you're in very common company.

Research also shows that women who experience bladder leaking in late pregnancy are more than twice as likely to continue experiencing it after birth — which is one of the reasons it's worth addressing during pregnancy rather than waiting to see how things settle

Common doesn't mean you're stuck with it

The research on pelvic floor muscle training (PFMT) during pregnancy is clear. A 2024 meta-analysis of 30 randomised controlled trials — nearly 7,000 women — found that structured pelvic floor training during pregnancy significantly reduces urinary leaking.

RANZCOG cites evidence that antenatal pelvic floor training, started early in pregnancy, can reduce bladder leaking in late pregnancy by 62%, and by 29% at three to six months postpartum.

Why "just doing your pelvic floor strengthening" isn't always the right advice

Not everyone who leaks during pregnancy has a weak pelvic floor. Some women have a pelvic floor that's tight, overactive, or poorly coordinated — and in that case, adding more repetitions to an already overloaded system can make things worse, not better. "Just do your pelvic floor exercises" is well-intentioned, but unfortunately, not always helpful.

Assessment tells you what you're actually dealing with.

A physiotherapy assessment can help identify whether the pelvic floor is weak, hypertonic, or something more complicated, and builds a program around that. Generic pelvic floor advice is easy to find. A program that fits your body is a different thing entirely.

What this means if you're currently pregnant

If you're already experiencing leaking:

• It's common, but it's not something to simply accept or wait out

• Starting pelvic floor work earlier in pregnancy gives the best outcomes — there's still value in starting in the third trimester, but earlier is better

• An assessment-led program will be more effective than generic exercises

How we can help at Balanced Physiotherapy & Pilates

We see pregnant women at all stages of pregnancy at our Vincentia clinic.

A prenatal pelvic floor physiotherapy consultation covers a thorough assessment of your pelvic floor, bladder function, and any symptoms you're experiencing. From there, we'll build a program specific to what's happening in your body — not a handout, an actual plan.

If you're leaking and want to do something about it, or you simply want to know your pelvic floor is in good shape before birth, we'd love to see you.

References

Moossdorff-Steinhauser, H. F. A., Berghmans, B. C. M., Spaanderman, M. E. A., & Bols, E. M. J. (2021). Prevalence, incidence and bothersomeness of urinary incontinence between 6 weeks and 1 year post-partum: A systematic review and meta-analysis. International Urogynecology Journal, 32(7), 1633–1652. https://doi.org/10.1007/s00192-021-04738-4

Baruch, Y., Braga, A., Salvatore, S., et al. (2023). Prevalence of pelvic floor disorders and their impact on quality of life in pregnant women. Neurourology and Urodynamics. https://pmc.ncbi.nlm.nih.gov/articles/PMC10137441/

Zhang, Y., et al. (2024). Pelvic floor muscle training during pregnancy for prevention of urinary incontinence and perineal tears: A systematic review and meta-analysis. Acta Obstetricia et Gynecologica Scandinavica. https://doi.org/10.1111/aogs.14744

Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). Pelvic floor health. https://ranzcog.edu.au/resources/pelvic-floor-health/