Labor Induction

Labor induction is the use of medications or other methods to bring on (induce) labor.

Labor is induced to stimulate contractions of the uterus in an effort to have a vaginal birth. Labor induction may be recommended if the health of the mother or fetus is at risk. Some of the reasons for inducing labor include the following:

• Your pregnancy has lasted more than 41 to 42 weeks.

• You have health problems, such as problems with your heart, lungs, or kidneys.

• There are problems with the placenta.

• There are problems with the fetus, such as poor growth.

• There is a decrease in amniotic fluid.

• You have an infection of the uterus.

• You have gestational diabetes or had diabetes mellitus before pregnancy.

• You have chronic hypertension, preeclampsia, or eclampsia.

• You have prelabor rupture of membranes (PROM).

Sometimes labor induction may be needed even if it means that the fetus will be born early. In these cases, the risks of continuing the pregnancy outweigh the risks of the fetus being born too early.

When you choose labor induction and you and your fetus are healthy, it is called elective induction. For example, labor may be induced at your request for reasons such as physical discomfort, a history of quick labor, or living far away from the hospital.

Labor induction may also be considered for healthy women at 39 weeks of pregnancy to reduce the chance of cesarean birth. Read Induction of Labor at 39 Weeks to learn more.

Elective induction should not be done before 39 weeks of pregnancy.

Some conditions may make a vaginal delivery unsafe for you or your fetus. Some of these conditions include the following:

• Placenta previa (the placenta covers the opening of the uterus)

• The fetus is lying sideways in the uterus or is in a breech presentation

• Prolapsed umbilical cord (the cord has dropped down in the vagina ahead of the fetus)

• Active genital herpes infection

• Some types of previous uterine surgery, such as certain types of cesarean birth or surgery to remove fibroids

In these situations, you may need a cesarean birth to protect the health of you and your fetus.

To prepare for labor and delivery, the cervix begins to soften (ripen), thin out, and open. These changes usually start a few weeks before labor begins. Sometimes when labor is going to be induced, the cervix is not yet "ripe" or soft. This means that labor cannot progress.

Your obstetrician–gynecologist (ob-gyn) will check to see if your cervix has started this change. The Bishop score may be used to rate the readiness of the cervix for labor. With this scoring system, a number ranging from 0 to 13 is given to rate the condition of the cervix. A Bishop score of less than 6 means that your cervix may not be ready for labor.

Ripening the cervix is a process that helps the cervix soften and thin out in preparation for labor. Medications or devices may be used to soften the cervix so it will stretch (dilate) for labor.

Ripening of the cervix can be done with medications or with special devices.

Prostaglandins are medications that can be used to ripen the cervix. They are forms of chemicals made naturally by the body. These medications can be inserted into the vagina or taken by mouth.

Some prostaglandins are not used if you have had a previous cesarean birth or other uterine surgery to avoid increasing the possible risk of uterine rupture (tearing).

• Laminaria are thin rods inserted into the cervix to dilate it. They are made of a substance that expands when it absorbs water.

• A catheter (small tube) with an inflatable balloon on the end. The tube is inserted through the vagina and into the opening of the cervix. Then the balloon expands, which helps open the cervix.

Stripping the membranes, also called sweeping the membranes, is a common way to induce labor. The ob-gyn sweeps a gloved finger between the amniotic sac and the wall of your uterus, separating the fetal membranes from the cervix.

This action is done when the cervix is partially dilated. This action may cause your body to release prostaglandins, which soften the cervix and may cause contractions.

Oxytocin is a hormone that causes contractions of the uterus. It can be used to start labor or to speed up labor that began on its own. Contractions usually start about 30 minutes after oxytocin is given.

Oxytocin is given through an intravenous (IV) line in the arm. A pump hooked up to the IV tube controls the amount given. Your condition, your contractions, and the fetus’s heart rate will be monitored when you are given this medication.

When your water breaks, the fluid-filled amniotic sac that surrounds the baby has ruptured (burst). Most women go into labor within hours after their water breaks. If the sac hasn't burst already, breaking it can start contractions. Or if the contractions have already started, breaking the sac can make them stronger or more frequent.

To rupture the amniotic sac, an ob-gyn makes a hole in the sac with a special device. This procedure, called an amniotomy, may be done before or after you have been given oxytocin.

Amniotomy can be done to start labor when the cervix is dilated and the baby's head has moved down into the pelvis. Most women go into labor within a few hours after the amniotic sac breaks, but sometimes oxytocin may be needed.

One risk is that when oxytocin is used, the uterus may be overstimulated. This may cause the uterus to contract too often. Too many contractions may lead to changes in the fetal heart rate. If there are problems with the fetal heart rate, oxytocin may be reduced or stopped. Other treatments may be needed to steady the fetal heart rate.

Other risks of labor induction may include

• chorioamnionitis, an infection of the amniotic fluid, placenta, or membranes

• infection of the baby

• rupture of the uterus (this is rare)

Medical problems that were present before pregnancy or occurred during pregnancy may contribute to these complications. To help prevent these complications, the fetal heart rate and force of contractions may be electronically monitored during labor induction.

Sometimes labor induction doesn't work. If you and your pregnancy are doing well and the amniotic sac has not ruptured, you may be given the option to go home. You can schedule another appointment to try induction again. If your labor starts, you should go back to the hospital.

If you or your baby are not doing well during or after attempting induction, a cesarean birth may be needed. Although most cesarean births are safe, there may be additional risks for you, including

• infection

• hemorrhage (heavy bleeding)

• complications from anesthesia

The recovery time after a cesarean birth is usually longer than for a vaginal birth.

There are also considerations for future pregnancies. With each cesarean birth, the risk of serious placenta problems in future pregnancies goes up. In addition, the number of cesarean births you have had is a major factor in how you will give birth to any future babies.

Amniotic Fluid: Fluid in the sac that holds the fetus.

Amniotic Sac: Fluid-filled sac in a woman's uterus. The fetus develops in this sac.

Amniotomy: Artificial rupture (bursting) of the amniotic sac.

Anesthesia: Relief of pain by loss of sensation.

Breech Presentation: A position in which the feet or buttocks of the fetus appear first during birth.

Cervix: The lower, narrow end of the uterus at the top of the vagina.

Cesarean Birth: Birth of a fetus from the uterus through an incision (cut) made in the woman's abdomen.

Chorioamnionitis: A condition during pregnancy that can cause unexplained fever with uterine tenderness, a high white blood cell count, rapid heart rate in the fetus, rapid heart rate in the woman, and/or foul-smelling vaginal discharge.

Diabetes Mellitus: A condition in which the levels of sugar in the blood are too high.

Eclampsia: Seizures occurring in pregnancy or after pregnancy that are linked to high blood pressure.

Fetus: The stage of human development beyond 8 completed weeks after fertilization.

Fibroids: Growths that form in the muscle of the uterus. Fibroids usually are noncancerous.

Genital Herpes: A sexually transmitted infection (STI) caused by a virus. Herpes causes painful, highly infectious sores on or around the vulva and penis.

Gestational Diabetes: Diabetes that starts during pregnancy.

Hemorrhage: Heavy bleeding.

Hormone: A substance made in the body that controls the function of cells or organs.

Hypertension: High blood pressure.

Intravenous (IV) Line: A tube inserted into a vein and used to deliver medication or fluids.

Kidneys: Organs that filter the blood to remove waste that becomes urine.

Laminaria: Slender rods made of natural or synthetic material that expand when they absorb water. Laminaria are inserted into the opening of the cervix to widen it.

Obstetrician–Gynecologist (Ob-Gyn): A doctor with special training and education in women's health.

Oxytocin: A hormone made in the body that can cause contractions of the uterus and release of milk from the breast.

Placenta: An organ that provides nutrients to and takes waste away from the fetus.

Placenta Previa: A condition in which the placenta covers the opening of the uterus.

Preeclampsia: A disorder that can occur during pregnancy or after childbirth in which there is high blood pressure and other signs of organ injury. These signs include an abnormal amount of protein in the urine, a low number of platelets, abnormal kidney or liver function, pain over the upper abdomen, fluid in the lungs, or a severe headache or changes in vision.

Prelabor Rupture of Membranes (PROM): Rupture of the amniotic membranes that happens before labor begins. Also called premature rupture of membranes.

Prostaglandins: Chemicals that are made by the body that have many effects, including causing the muscles of the uterus to contract, usually causing cramps.

Umbilical Cord: A cord-like structure containing blood vessels. It connects the fetus to the placenta.

Uterus: A muscular organ in the female pelvis. During pregnancy, this organ holds and nourishes the fetus. Also called the womb.