What Is Inducing Labor?
Inducing labor refers to different treatments used to either start or move your labor along at a faster pace. The goal is to bring on contractions or to make them stronger.
Several methods can help get labor started.
Rupturing the Membranes
Amniotic fluid is the water that surrounds your baby in the womb. Membranes or layers of tissue hold in this fluid. One method of inducing labor is to do what is called “break the bag of waters” or rupture of membranes.
- Your doctor or midwife will do a pelvic exam and 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 some 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 the 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 health care provider can use a medicine called prostaglandins.
The medicine is placed in your vagina next to the 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) and is used 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 the 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 doctor may be able to reduce the dose. Many women choose to have an epidural block when they are receiving oxytocin.
Why Is It Done?
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 - 36 weeks).
- When 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.
Oxytocin may also be started after a woman’s labor has started, but her contractions have not been strong enough to dilate cervix.
Wing DA, Farinelli CK. Abnormal labor and induction of labor. In: Gabbe SG, Niebyl JR, Simpson JL, et al, eds. Obstetrics: Normal and Problem Pregnancies. 6th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 14.
Reviewed By: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.