Amniotic fluid is the water that surrounds your baby in your womb. It contains membranes or layers of tissue. One method of inducing labor is to "break the bag of waters" or rupture the membranes.

• Your health care provider will do a pelvic exam and will guide a small plastic probe with a hook on the end through your cervix to create a hole in the membrane. This does not hurt you or your baby.
• Your cervix must already be dilated and the baby's head must have dropped down into your pelvis.

Most of the time, contractions will begin within minutes to a few hours afterward. If labor does not begin after a few hours, you may receive a medicine through your veins to help start contractions. This is because the longer it takes for labor to start, the greater your chance of getting an infection.

Early in your pregnancy your cervix should be firm, long, and closed. Before your cervix starts to dilate or open, it must first become soft and begin to "thin out."

For some, this process may begin before labor has started. But if your cervix has not begun to ripen or thin, your provider can use a medicine called prostaglandins.

The medicine is placed in your vagina next to your cervix. Prostaglandins will often ripen, or soften the cervix, and contractions may even begin. Your baby's heart rate will be monitored for a few hours. If labor does not begin, you may be allowed to leave the hospital and walk around.

Oxytocin is a medicine given through your veins (IV or intravenous) to either start your contractions or make them stronger. A small amount enters your body through the vein at a steady rate. The dose may be slowly increased as needed.

Your baby's heart rate and the strength of your contractions will be monitored closely.

• This is done to make sure your contractions are not so strong that they harm your baby.
• Oxytocin may not be used if tests show that your unborn baby is not getting enough oxygen or food through the placenta.

Oxytocin will often create regular contractions. Once your own body and uterus "kick in," your provider may be able to reduce the dose.

There are many reasons why you may need labor induction.

The induction of labor may be started before any signs of labor are present when:

• The membranes or bag of waters breaks but labor has not begun (after your pregnancy has passed 34 to 36 weeks).
• You pass your due date, most often when the pregnancy is between 41 and 42 weeks.
• You have had a stillbirth in the past.
• You have a condition such as high blood pressure or diabetes during pregnancy that may threaten the health of you or your baby.
• Your baby is showing signs of stress while being monitored prior to onset of labor.
• An ultrasound indicates a potential complication with the fetal well being.
• You have other medical conditions that requires induction of labor for delivery in order to start treatment for the condition.

Oxytocin may also be started after a woman's labor has started, but her contractions have not been strong enough to dilate her cervix.

Labor induction; Pregnancy - inducing labor; Prostaglandin - inducing labor; Oxytocin - inducing labor

Levine LD, Srinivas SK. Induction of labor. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 12.

Thorp JM, Grantz KL. Clinical aspects of normal and abnormal labor. In: Lockwood CJ, Copel JA, Dugoff L, et al, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2023:chap 40.

Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.