How Does Pregnancy Affect Bladder Control?

Your bladder doesn’t wait for the bump. Plenty of women notice the first change weeks before anyone else can tell they’re pregnant, standing in the bathroom line for the third time before lunch.

Pregnancy changes bladder control in stages, and each stage has a different cause. That’s why the advice that fits at 8 weeks isn’t the advice you need at 36. Somewhere between 40% and more than half of pregnant people have bladder control problems, according to Cleveland Clinic¹, so whatever week you’re in, you have a lot of company.

Why do I pee so much in early pregnancy?

Your kidneys got busier. Early in pregnancy, blood flow to the kidneys climbs, and so does the rate at which they filter your blood. A review in Advances in Chronic Kidney Disease puts that filtration increase at about 50% above non-pregnant levels, and the rise starts fast: one measure of kidney filtration was about 45% higher by week 9.

In the first trimester, that extra filtering is the big one. The other cause, a growing uterus pressing on the bladder, mostly shows up later. At 12 weeks the uterus is still small, Cleveland Clinic¹ points out, and frequent peeing gets more common as pregnancy goes on.

A true flood, more than 3 liters of urine a day, is rare in pregnancy, according to the same kidney review. Your bladder is getting more deliveries than it’s used to, and they don’t stop at 2 a.m.

The NHS² says needing to pee a lot often starts in early pregnancy and sometimes continues until the baby is born. Leaks can start this early too, Cleveland Clinic¹ notes, though they get more likely as the months go on.

Why does my pelvic floor feel weaker as pregnancy goes on?

Two things are working on it at once. Hormones and weight.

Your pelvic floor is the sling of muscle under your bladder and bowel that helps hold everything up and keeps the exits closed. During pregnancy, a hormone called relaxin softens muscles and ligaments so your body can make room for the baby. The pelvic health physios at Royal Berkshire Hospital, an NHS² trust, point out that your pelvic floor softens along with everything else. Rising progesterone loosens these muscles too.

Softer muscles are worse at holding the door shut when pressure spikes. So you cough, sneeze, laugh, lift a toddler, or bend to grab a dropped sock, and a little escapes. That pattern is usually called stress incontinence, and Cleveland Clinic¹ calls it the most common type in pregnancy. The NHS² lists a less obvious trigger too: getting up from a chair.

Some women get the other kind instead, or both. With urge incontinence, the bladder muscle squeezes on its own and you get a sudden, can’t-wait need to go.

Then there’s the weight. As the baby gets heavier, it leans harder on the pelvic floor, and leaking can get worse as the weeks go by.

Is the third trimester the worst for leaks?

Usually, yes. Cleveland Clinic¹ says pregnancy incontinence is most common in the third trimester, when the baby is heaviest and presses hardest on the bladder.

In later pregnancy, the NHS² says, the baby’s head pressing on your bladder is what keeps sending you back to the toilet. If you’ve ever felt a kick land right on it, you know the feeling… the baby found the button.

Night trips pile up in these last weeks. The NHS² suggests cutting out drinks in the late evening if you’re getting up to pee at night. Note the wording. Late evening, not all day.

Is it pee, or is it my waters?

This is the one we’d want you to have an answer ready for, because late in pregnancy a wet pad isn’t always urine.

The NHS³ is frank that it’s sometimes hard to tell amniotic fluid from pee. When your waters break you may feel a slow trickle or a sudden gush you can’t control. Cleveland Clinic¹ describes urine as watery and clear or pale yellow, with a slight ammonia smell or no smell. Amniotic fluid is thin, odorless, and clear, or straw-colored, and it can be tinged brown or green.

Here’s where we land. If you can’t tell, treat it as possible waters and call your midwife, OB, or labor and delivery unit. That call is routine for them. The NHS³ says to contact your midwife if your waters break before labor starts, to tell your midwife immediately if the fluid is smelly or colored or you’re losing blood, and to call urgently if you’re under 37 weeks and think labor has started.

Why does a bladder infection matter more in pregnancy?

Pregnancy makes urinary tract infections easier to get, and harder to ignore safely. The urinary tract changes as the uterus grows, especially between weeks 6 and 24, according to Cleveland Clinic¹. Pressure on the bladder can slow urine flow and give bacteria a place to grow, and pregnancy also turns down some of your immune defenses.

The tricky part is that a UTI can feel a lot like ordinary pregnancy peeing, with more frequent, more urgent trips. Pain or burning, cloudy or strong-smelling pee, or blood in your pee can be signs of an infection, and only a urine test can tell for sure. The NHS² says to contact your doctor within 24 hours if you have pain when peeing or see blood in it.

Some infections never announce themselves. That’s one reason an early prenatal visit includes a urine culture: the US Preventive Services Task Force⁴ recommends screening pregnant people for bacteria in the urine, symptoms or not.

If the infection reaches the kidneys, it can cause early labor or low birth weight, according to Cleveland Clinic⁵. Fever, chills, back or side pain, nausea, or vomiting along with urinary symptoms can be signs the infection has spread. Call your OB, midwife, or labor and delivery unit right away, and if you can’t reach them, go to urgent care or the ER.

What helps while you’re pregnant?

Start with the squeezes. And start early. Run it by your OB or midwife first, especially if you’ve been told to limit activity.

A 2020 Cochrane review found that women with no leaks who did structured pelvic floor training during pregnancy probably had a 62% lower risk of reporting leakage in late pregnancy than women who didn’t. In the middle months after birth, their risk was 29% lower.

For women already leaking, the review found no evidence that training during pregnancy reduced leakage later on, and the authors call its effect as a treatment uncertain.

We read that as an argument for starting before you need it. If you’re leaking now, that’s your cue to ask for more help. A pelvic health physical therapist can check whether you’re squeezing the muscles you think you are, and build a plan around your body.

A few more habits are worth building now.

The Royal Berkshire leaflet describes holding a gentle pelvic floor squeeze for 3 to 5 seconds, relaxing for at least 5, and building toward 10-second holds, at least three times a day. If you’re heavily pregnant, it suggests lying on your side to do them. It also recommends squeezing those muscles a beat before you cough, sneeze, lift, or stand up from sitting.

The same leaflet suggests going to the toilet about every two to two and a half hours during pregnancy. On a schedule, before the urge gets loud.

Keep drinking. The Office on Women’s Health⁶ says cutting back on fluids to leak less is a mistake, because enough fluid helps prevent UTIs and constipation. Trim the late-evening glass if nights are rough, and leave the daytime water bottle alone.

Mind the other exit too. Straining to poop takes a toll on your bladder, and caffeine, fizzy drinks, and spicy or acidic foods can set off urgency for some women, Cleveland Clinic¹ says. Fiber and decaf are easy first moves.

Wear what makes you comfortable. An absorbent pad or leak-proof underwear can take the dread out of a sneeze.

When should I call my clinician?

Leaking a little when you sneeze in the third trimester is common and worth mentioning at your next appointment. These need a faster call, and some of them can’t wait:

• Pain or burning when you pee, cloudy or strong-smelling pee, or blood in your pee (contact your doctor within 24 hours, per the NHS²)
• Fever, chills, back or side pain, nausea, or vomiting along with urinary symptoms (call your OB or midwife right away, and if you can’t reach them, go to urgent care or the ER)
• A trickle or gush of fluid you can’t stop, or wetness you can’t identify as pee
• Fluid that is green, brown, smelly, or bloody (call your midwife, OB, or labor and delivery unit immediately)
• Any fluid leak or signs of labor before 37 weeks (call your labor and delivery unit or maternity unit immediately)
• Trouble passing urine, or feeling like your bladder won’t empty (call your OB or midwife the same day)

If you have heavy bleeding, severe pain, or think you or your baby are in danger, call 911 or your local emergency number.

Does it go away after the baby comes?

It tends to ease off. The Office on Women’s Health⁶ says most bladder problems from pregnancy go away after childbirth once the muscles have had time to heal, and to talk to your doctor, nurse, or midwife if problems last past six weeks after delivery. Birth itself brings its own changes to the pelvic floor, and we cover those in our articles on leakage after childbirth.

Back to that bathroom line at 8 weeks. Usually that’s your kidneys clocking in early (a pee that burns or stings is the exception, and worth a call). While you wait your turn, you may as well do a few squeezes.