How contractions work and feel

Uterine contractions will push your baby out

Your uterus is shaped like a pear, sitting upside down in your pelvis. The "stem end" is called the cervix, which is the neck, or opening, at the bottom of your uterus.

The wall of your uterus is a very specialized muscle. It grows and stretches as your baby grows. When the time comes for your baby to be born, this muscle will tighten or contract in a rhythmic fashion from top to bottom. This helps efface, or thin, your cervix, and pushes your baby's head against the cervix to help dilate, or open, it.

One way your progress in labor is measured is by how effaced and dilated your cervix is.

• Effacement is measured in percentages (30 percent effaced, 100 percent effaced).
• Dilation is measured in centimeters.

After your cervix is fully effaced and dilated, then contractions help push your baby down into the vagina and out.

Most women feel contractions as a tightening sensation, like your baby is balling up. Some say contractions feel like menstrual cramps. Sometimes a dull backache is the main symptom. The pain may also be felt on the front of the thighs.

True labor or "false" contractions?

• Effective contractions that signal true labor often start at the top of the uterus and go down, or start in the back and come around to the front. Visualize your uterus as a muscular bag that squeezes in waves from the top down to push your baby out.
• Call your health care provider if you are less than 37 weeks pregnant and have six to eight or more contractions in an hour.
• "False" contractions also mean call your health care provider. Contractions during pregnancy used to be called "false," "practice" or "Braxton-Hicks" contractions and were treated as though they were a normal part of pregnancy.

A contraction may feel like a firming and tightening of your entire uterus. Your baby's kick or movement will feel more like a fluttering or a sudden, soft poke or a firming in just a small part of your uterus.

Related Links

How to time contractions

Relaxation techniques

When to call your health care provider: Preterm labor

How do you know you're in labor?

Second trimester

First published: 10/04/2002
Last updated: 06/19/2003

Reviewed by: Allina Patient Education experts