Labor contractions typically start 15 to 30 minutes apart, lasting only 30 to 45 seconds each. They feel mild at first, often compared to menstrual cramps, and they may not follow a consistent pattern right away. Over hours, they gradually move closer together, grow stronger, and last longer as your body progresses toward delivery.
Early Labor: What the First Contractions Feel Like
In early labor (called the latent phase), contractions are short, relatively mild, and widely spaced. They can range anywhere from 5 to 30 minutes apart, and many people describe them as a tightening across the abdomen or low back pressure similar to period cramps. Each contraction typically lasts 30 to 45 seconds at this stage. The key feature of early labor is inconsistency: contractions may come every 10 minutes for a while, then spread out to every 20 minutes, then tighten up again.
This phase is also the longest part of labor. A large population-based study found that the median duration of early labor is about 16 hours for first-time mothers and roughly 9.5 hours for those who have given birth before. That’s a wide window, and the range varies considerably. Some first-time mothers experience early labor for over 26 hours, while others move through it in under 10. During all of that time, the cervix is slowly opening from closed to about 6 centimeters.
How Contractions Change as Labor Progresses
The shift from early labor to active labor is defined by contractions that become stronger, longer, and more predictable. During active labor, contractions typically come every 3 to 5 minutes, and the cervix dilates from 6 centimeters to the full 10 centimeters needed for delivery. Each contraction lasts longer too, building from those initial 30-second squeezes to a full minute or more.
The most intense stretch comes at the end of active labor, sometimes called transition. Contractions during this phase come very close together and can last 60 to 90 seconds each, with only brief rest periods in between. This part is short, usually 30 minutes to 2 hours, but it’s the most physically demanding.
How to Time Contractions Correctly
The interval between contractions is measured from the start of one contraction to the start of the next, not from the end of one to the beginning of the next. This distinction matters because it gives a consistent measure regardless of how long each contraction lasts. If a contraction begins at 2:00 and the next one starts at 2:12, they are 12 minutes apart.
Track both the frequency (how far apart) and the duration (how long each one lasts). Most contraction timer apps do this automatically. Write down or log at least five or six contractions in a row to see whether a real pattern is forming. A single stretch of regular contractions doesn’t always mean active labor has started.
The 5-1-1 Rule
A widely used guideline for knowing when early labor has shifted into something more serious is the 5-1-1 rule: contractions are consistently five minutes apart, each one lasts about one minute, and this pattern has continued for at least one hour. Meeting all three criteria is a common signal that it’s time to head to the hospital or birthing center. For first-time mothers especially, arriving before this point often means being sent home to wait.
Braxton Hicks vs. Real Contractions
Not every tightening in your uterus means labor is starting. Braxton Hicks contractions can begin as early as the second trimester and become more noticeable in the final weeks of pregnancy. The critical difference is in the pattern. Braxton Hicks contractions are irregular, don’t get closer together over time, and often stop entirely when you change positions, walk around, or drink water. Real labor contractions follow a pattern that builds: they get closer together, last longer, and feel progressively stronger regardless of what you do.
Prodromal Labor: The Tricky Middle Ground
Some people experience something called prodromal labor, which can be genuinely confusing. These contractions can come as frequently as every five minutes, last up to a minute each, and feel mildly painful. They look a lot like real labor on paper. The difference is that prodromal labor never progresses beyond that point. The contractions don’t get closer than five minutes apart, don’t intensify, and don’t cause the cervix to dilate.
Prodromal labor can come and go for days or even weeks before true labor begins. It’s physically exhausting and emotionally frustrating, but it’s not dangerous. The pattern to watch for is change: real labor contractions evolve over time, getting closer, longer, and more intense. Prodromal contractions stay stuck at the same level.
What Causes Contractions to Start
The uterus is one of the few muscles in the body that contracts on its own without needing a signal from the nervous system. Researchers have studied uterine tissue for decades and have never identified a single pacemaker cell that triggers the process. Instead, the muscle cells of the uterus appear to generate their own electrical impulses, which then spread to neighboring cells. Hormonal shifts near the end of pregnancy, particularly rising levels of oxytocin and prostaglandins, increase the sensitivity of these muscle cells and make coordinated contractions more likely. Once that process gains momentum, contractions become rhythmic and progressively stronger as the feedback loop between the uterus and the brain’s hormonal signals intensifies.