5 Things That Cause Contractions in Your Third Trimester

Contractions won't begin in earnest until the baby's delivery day arrives, but you might feel contractions on and off during the third trimester.

"You may get an occasional, uncomfortable tightening in the stomach — that's your uterus getting its act together, and exercising for the grand finale," says Paul du Treil, M.D., director of maternal and child health at Touro Infirmary in New Orleans.

So when can you expect to feel contractions? Here's the scoop.

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Preterm labor — which occurs before you've finished your 36th week of pregnancy — may not even be painful. But although an occasional twinge or tightening of the uterine wall is fine, you need to watch for patterns that don't go away, as that could be a sign that labor is starting before it should.

"If they're having a lot of contractions for several hours in a row, then you need to come in and be evaluated," says Bart Putterman, M.D., an ob-gyn at Texas Children's Pavilion for Women in Houston.

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You may not want to slow down, but sometimes overtaxing your body during the third trimester could cause your uterus to start contractions.

"If you're doing too much, you could cause Braxton Hicks contractions or false labor," Dr. Putterman says. These contractions aren't the real deal — and often go away once you put your feet up and chill -- but it's best to avoid them if you can." 

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Dehydration can also kick-start those Braxton Hicks contractions, so make sure you're drinking plenty of water.

"If a patient calls about their contractions, one of the first things we tell them is to go drink a big glass of water," Dr. Putterman says. "If they don't feel better, they probably need to come in and get checked." 

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If you develop painful contractions and vaginal bleeding, you need to contact the doctor immediately.

"If the tightness lasts more than two minutes, they need to call right away," says Siobhan Kubesh, a certified midwife with OBGYN North in Austin. "Contractions that do not go away are a sign of trouble." Even in the thick of labor, your body will give you a short break between contractions, so if your contractions don't take a breather, it could indicate a dangerous complication, such as uterine rupture. 

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It's finally time for your baby to arrive! Although the contractions may start out irregularly, if you've reached your baby's birth day, they'll soon start developing a regular rhythm.

"If it's real labor, the contractions are going to gradually get closer together and longer and stronger," Dr. Putterman says.

In most cases, doctors will recommend that you head for the hospital or birthing center once your contractions are a minute long and start four to five minutes apart, but your health-care provider may suggest a different threshold for you, depending on your risk factors, your proximity to the hospital, and other individual issues. Follow your doctor or midwife's advice — and get ready to snuggle that baby!

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