Labor contractions are the physical way your uterus tightens to promote delivery of your baby. All body muscles tighten and shorten (contract) when they’re being used. And the uterus is one of the strongest muscles in the body.

Labor contractions are often described as feeling like a wave, because their intensity slowly rises, peaks, and then slowly decreases.

Labor contractions often:

  • radiate from your back to the front of your core
  • make your whole belly rock hard
  • feel like cramps
  • include pelvic pressure
  • include a dull backache

The word commonly associated with contractions is “pain,” but you can redirect your mind to think of them as productive, demanding, and just intense.

Read on to learn more about what to expect from contractions, and what you should do once contractions start.

Contractions help move a baby downward by tightening the top of the uterus and applying pressure on the cervix. This pressure causes the cervix to open, or dilate.

Contractions can last anywhere from a few seconds to a few minutes.

The hormone oxytocin stimulates labor contractions and will keep them happening all throughout labor. As labor progresses, contractions usually:

  • get more intense
  • last longer
  • come closer together

Sometimes, contractions are less frequent once you’re finally pushing the baby out, but they’ll still be very strong to work with you to get the baby out.

For a full-term baby, true labor contractions won’t start until your baby is at least 37 weeks.

If you experience contractions earlier than 37 weeks, seek immediate medical attention. These are known as preterm contractions, and may be a sign that you’re going into labor before your baby has fully developed.

You may also feel Braxton-Hicks contractions as early as the second trimester.

Braxton-Hicks contractions are sometimes called practice contractions. They’re believed to help prepare your body for labor. These generally don’t last very long and aren’t painful.

Contractions don’t always mean you’re in active labor, either.

Some women experience contractions on and off for a couple of days before labor finally begins. This is known as prodromal labor.

What are the symptoms of labor? | Labor signs

Call your doctor or midwife if you’re having contractions, whether they’re coming regularly or irregularly spaced.

If you’re having contractions in a regular pattern — meaning they’re spaced about the same distance apart — and you have the following signs, you’re probably in labor:

Cervical ripening or thinning is another sign, but you won’t be able to diagnose this symptom on your own. Only a trained doctor, midwife, or doula can tell you if your cervix is actually thinning and opening in preparation for the baby to be born.

How do you know your contractions are a sign of labor and not something else?

It may be difficult to know if you’re having contractions, round ligament pain, or indigestion — especially if you’re a first-time mom.

People talk about “real contractions” and “false labor” but instead of using such terms, pay attention to what you’re feeling so that you can talk to your doctor about it.

Often, resting, changing your position, and rehydrating will stop irregular contractions before real labor. Real labor won’t be stalled by these actions.

If your contractions are coming in a regular pattern and you have other signs of labor, call your doctor right away.

Timing contractions is an essential part of assessing if you’re in labor. Labor contractions will come in a regular time pattern that slowly increases in frequency.

Early in your third trimester, your doctor or midwife should start telling you what to expect and how to communicate about labor signs.

Ask them when they’d like you to head to the hospital or call them based on contraction timing.

Time your contractions from when one starts until the next one begins.

To time contractions:

  • When you feel the tightening in your abdomen, immediately note the time.
  • Try to notice if the contraction reaches a peak.
  • Once the tightening stops completely, note how long it lasted, but don’t stop timing the contraction.
  • Wait to feel the next tightening before restarting your stopwatch.

An analog clock is most accurate for timing contractions. You can also download a phone app with an easy timer button so that you don’t have to think about it at all. An app can be a lot more relaxing if you’re anxious.

A common rule of thumb for first-time mothers is 3-1-1: Contractions coming every 3 minutes, lasting 1 minute, and recurring for 1 hour.

If you’re having a hospital birth, your doctor may want you to call them before you head to the hospital. If they don’t mention their preference, ask during one of your appointments in your third trimester.

Also, depending on previous births or preexisting conditions, your doctor may ask you to be in touch even if your contractions are coming every 5 to 10 minutes.

The following is the usual timeline of contractions:

Labor stageDuration between contractionsLength of contraction
early labor5 to 30 minutes30 to 45 seconds
active labor3 to 5 minutes45 to 60 seconds
transition (final stage before pushing)30 seconds to 2 minutes60 to 90 seconds

At any point in pregnancy, you may feel your uterus contracting.

The following are some of the common types of contractions you may experience during pregnancy:

Preterm contractions

These contractions are real labor happening before your baby is ready to be born. You’ll have symptoms consistent with active labor.

Braxton-Hicks contractions

These are “practice” contractions that usually aren’t painful and shouldn’t be felt in your back. Dehydration, sex, or a full bladder can all trigger these contractions.

Back labor

This is a more focused kind of pain that some women feel during contractions. More than the usual back soreness you may experience during pregnancy, back labor is most commonly — though not always — caused by the baby’s position inside the uterus.

Back labor can include irregular contractions and longer time pushing.

There’s no guessing when a baby will be born.

A baby is considered full term once you’re 37 weeks pregnant. Labor often occurs between 37 and 40 weeks of pregnancy.

Contractions before 37 weeks are called preterm and run risks to the baby.

If you’re not full term and you have contractions that aren’t going away by resting and hydrating, call your doctor right away. Most offices have an answering service after-hours, so call any time, day or night.

We asked some moms to describe their contractions, and here’s what they had to say:

“A squeezing surge that brings you closer to meeting your babe.” — Kaitlin.

“Intense tightening and sense of pressure that slowly built, peaked, then released.” — Lauren.

“Sort of like stronger versions of period cramping. I was in labor for 2 days, and that whole time I didn’t actually feel that the contractions were painful until they induced me, at which point, bang! Painful contractions.” — Marie

If you’re at term and are having contractions, it’s time to focus and get ready for D-day (delivery day).

Keep in mind that it could be a very long day, and for some women, it may even extend over several days.

First and foremost, relax. Especially in early labor, day or night, you don’t want to waste any energy.

Take a bath or sit down and read.

While you’re waiting:

  • Keep a written log of your contraction timing.
  • Eat light snacks that won’t upset your stomach.
  • Call your doctor or midwife, and care team (doula, partner, or babysitter for older kids).
  • Do something fun or relaxing to pass the time.
  • Stay hydrated.
  • Pack your bag and put the away message on your email because it’s time to have a baby.

If you’re in preterm, call your doctor or midwife immediately, or just head straight to the hospital. If you’re in preterm labor, you’ll want to be evaluated as soon as possible.

If you haven’t packed your hospital bag yet, grab a few essentials and ask a friend or family member to pack additional stuff to bring to you at the hospital.