Published on August 26, 2021

How to Know When It's Time

pregnant woman holding belly


The average length of a pregnancy is 40 weeks, but there's no way to predict when you will actually go into labor. Most ladies deliver between 38 and 41 weeks of pregnancy. The more you know about what to expect during labor, the better prepared you'll be once it begins.

We don't know what causes labor to start. We think hormones play a role. Some patients are able to know when labor begins; with others, the signs are more vague.

Signs of Labor

When labor starts, the cervix dilates or opens and the uterus contracts at regular intervals. These contractions may last for 30 or 60 seconds. The abdomen becomes hard and then the uterus relaxes and becomes soft again. There are four things you may notice when labor starts.

  • Lightning is when the pregnancy feels lighter. The baby’s head descends into the pelvis and so you may not feel as much pressure from the weight of your fetus. Also, you may notice that the shape of your abdomen changes, so it looks like you're carrying the baby lower because it drops into the pelvis. Lightning can occur anywhere from a few weeks to a few hours before labor begins.
  • Loss of the mucus plug. A thick mucus plug forms at the cervix. As the cervix begins to dilate, the mucus plug is discharged from the cervix. Sometimes it's clear mucus. Sometimes it may be pinkish or even blood tinged. Patients may discharge this suddenly and expel it completely, or they may lose it over time.
  • Contractions. The uterus contracts. You may notice a pain in your back or in your abdomen. Sometimes you notice it in the pelvis. It feels much like menstrual cramps. Contractions can happen at a regular interval and get closer and closer over time.
  • Ruptured membranes. The fetus lives in an amniotic sac filled with fluid, and when this sac ruptures, it is called rupture of membranes or breaking of water. Some patients notice a trickle of fluid; others may notice a large gush. When this happens, you should report to your OB Emergency Department or contact your provider.

Braxton-Hicks Contractions

Braxton-Hicks contractions are false labor pains. They usually occur within the last month of pregnancy, and they are practice contractions. You'll notice them irregularly throughout the day. Sometimes they can be very intense and painful at other times just a slight cramp, like menstrual cramps. The way to distinguish Braxton-Hicks contractions from true labor is that Braxton Hicks contractions may change with movement or with rest.

False vs. True Labor

Four factors distinguish true labor from false labor:

  • Timing and frequency of the contractions. True labor contractions come at regular intervals. Their timetable lasts for about 60 to 90 seconds, and they get closer together as time goes on. False contractions don't have a pattern, and they don't get closer together.
  • Change with movement. True labor comes when you're at rest or when you move around; contractions come at regular intervals. Despite what you're doing, false labor contractions may ease when you rest or sometimes when you go for a walk. It makes the contractions improve. They may also stop with a change in position.
  • Strength of the contraction. True labor contractions get stronger and closer together over time. False labor contractions will usually get weaker and peter out when you rest or hydrate.
  • Location of the pain. True labor pain starts in the back and moves to the front. Sometimes you may notice that your belly gets really hard or firm. Usually in false labor, pain is only felt in the front from the weight of the pregnancy.

When to Go

You should go to the hospital if you notice any of these signs:

  • If your water is broken, even if you have no contractions.
  • If you're bleeding heavily from the vagina
  • If you have constant severe pain with no relief between contractions
  • If you notice that your fetus is moving less than normal.

Length of Labor

For women having their first baby, labor can last from 12 to 18 hours. If you've had a baby before, labor shortens to about eight to 10 hours.

But every woman is different, and your labor may not be like your mother's or your sister’s or your friend’s. Your labor may even be different from your first baby to your second baby.

Labor progresses about a centimeter an hour with your first pregnancy. It goes a little faster at 1.2 centimeters an hour for subsequent pregnancies. Labor usually follows a pattern, but it's difficult to predict when babies will be born.

Be Prepared

  • Pack a bag for the hospital. You can keep it in your trunk or at home.
  • Plan for the care of your children or your pets while you're hospitalized.
  • Make sure you have a car seat to bring your new baby home safely.
  • For working moms, talk with your supervisors about your maternity leave, which usually ranges from six to 12 weeks.

Thank you for choosing the NMMC Women’s Hospital. We're delighted to participate in your care. If you have any questions, please reach out to us. We're happy to help.

      The more you know about what to expect during labor, the better prepared you'll be once it begins.