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What is labor?

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Labor is the process by which the fetus and the placenta leave the uterus. Delivery can occur in two ways, vaginally or by a cesarean delivery.

Labor occurs in three stages and can actually begin weeks before a woman delivers her infant. The first stage begins with the woman's first contractions and continues until she is dilated fully (10 centimeters, or 4 inches), which means the cervix has stretched to prepare for birth. The second stage is the active stage, in which the pregnant woman begins to push downward. It begins with complete dilation of the cervix and ends with the actual birth. The third stage, or placental stage, begins with the birth and ends with the completed delivery of the placenta and afterbirth.1

Just as pregnancy is different for every woman, the signs of labor and the length of time it can take to go through the three stages will vary from woman to woman. Some signs indicating that labor may be close (although in fact it might still be weeks away) may include1:

  • "Lightening." This term describes when the fetus "drops," or moves lower in the uterus. Not all fetuses drop before birth. Lightening gets its name from the feeling of lightness or relief that some women experience when the fetus moves away from the rib cage to the pelvic area. This allows some women to breathe easier, more deeply, and get relief from heartburn.
  • Increase in vaginal discharge. Called "show," the discharge can be clear, pink, or slightly bloody. This occurs as the cervix begins to dilate and can happen several days before labor or as labor begins.2

If you experience any of the following signs of labor at any point in your pregnancy you should contact your health care provider3:

  • Contractions every 10 minutes or more often
  • Change in color of vaginal discharge
  • Pelvic pressure
  • Low, dull backache
  • Vaginal spotting or bleeding
  • Abdominal cramps with or without diarrhea

Sometimes a woman's health care provider will recommend inducing labor (using medically supervised methods, such as medication, to bring on labor) if the health of the mother or the fetus is at risk.4 Unless delivery is medically necessary, a woman should wait until at least 39 weeks before delivering her infant to give her/him the best chance for healthy outcomes. During the last few weeks of pregnancy, the fetus is still developing its lungs, brain, and liver.5

The NICHD's National Child and Maternal Health Education Program currently focuses on raising awareness of the importance of waiting until 39 weeks to deliver a baby, unless medically necessary. The website and materials are designed for health care professionals, but resources on preterm birth are also included.

For more information, visit the U.S. Department of Health and Human Services' Office on Women's Health listing of pregnancy resources at http://womenshealth.gov/pregnancy.


  1. Department of Health and Human Services. (2010). Pregnancy—Labor and birth. Retrieved July 27, 2012, from http://www.womenshealth.gov/pregnancy/childbirth-beyond/labor-birth.html [top]
  2. American College of Obstetricians and Gynecologists. (2011). FAQs: How to tell when labor begins. Retrieved August 1, 2012, from http://www.acog.org/~/media/For%20Patients/faq004.pdf?dmc=1&ts=20120801T1121182122 External Web Site Policy (PDF - 188 KB) [top]
  3. March of Dimes. (n.d.). Signs of preterm labor. Retrieved July 31, 2012, from http://www.marchofdimes.com/pregnancy/labor.html External Web Site Policy [top]
  4. American College of Obstetricians and Gynecologists. (2012). FAQs: Labor induction. Retrieved August 6, 2012, from http://www.acog.org/~/media/For%20Patients/faq154.pdf?dmc=1&ts=20120806T1152493842 External Web Site Policy (PDF - 234 KB) [top]
  5. March of Dimes. (2011). Why at least 39 weeks is best for your baby. Retrieved July 31, 2012, from http://www.marchofdimes.com/pregnancy/getready_atleast39weeks.html External Web Site Policy [top]

Last Updated Date: 11/30/2012
Last Reviewed Date: 12/06/2013
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