Induced labor

Inducing labor is the process of initiating childbirth with artificial methods, such as medication, before labor begins naturally.


Purpose/Indictations
Natural or spontaneous labor is usually best. In some cases, however, labor is induced when it's better for the mother or baby to deliver sooner rather than wait for contractions to begin naturally. An induction may be needed if:
Your pregnancy has continued one to two weeks beyond your due date.

Your water has broken but labor doesn't follow on its own.

The amniotic fluid (which surrounds and protects the baby in the womb) is infected or low in volume.

You develop mild detachment of the placenta (a structure in the womb that develops during pregnancy to nourish the baby and help discard waste) from the uterus (a condition known as abruptio placenta).

You develop preeclampsia (a serious condition that develops usually after the 20th week of pregnancy and disappears once the baby is born).

You have an illness such as diabetes, kidney disease, chronic high blood pressure or lung disease.

The baby may have problems caused by poor growth or Rh incompatibility (a difference in the baby's and mother's Rh blood type).

You have a high risk of delivering before arriving at the hospital (due to a possible rapid labor or living a long way from the hospital) if labor is left to begin naturally.

The baby has died in the womb.
Labor would not be induced if:

The placenta blocks the birth canal (a condition known as placenta previa) or detaches from the uterus (a condition known as abruptio placenta) and there is major bleeding.

The umbilical cord comes out of the vagina.

The baby is too large or in the wrong position to pass through the birth canal.

You had a previous C-section (surgical delivery through the abdomen) that left a vertical scar in your uterus.

You have an active case of genital herpes.

Patient preparation
First, your doctor will verify that your baby is mature enough to be born without distress. He or she may verify the expected due date, do an ultrasound (using sound waves to create an image of the baby and your uterus) or do a nonstress test (a diagnostic test to measure the response of a baby's heartbeat to fetal movement, spontaneous contractions or other stimuli).
Your doctor will also verify that you're ready for delivery. An internal exam will be done to determine whether your cervix has softened in preparation for the birth or has actually started to open. (The cervix should be soft before labor is induced.) Your baby's position will also be evaluated. This information can be used to calculate your Bishop Score, a formula that helps predict the chance of a normal vaginal delivery.


Procedure
If your cervix isn't soft at the time of a planned induction, your doctor may use prostaglandin gel, a natural substance that helps soften the cervix and induce labor, or a synthetic form of the gel. Various cervical dilators, which are placed in the cervix several hours before the induction, can also soften the cervix. When the cervix is soft and thinning, there are several techniques that may be used to stimulate the contractions that will open the cervix and allow the baby to begin descending through the birth canal.
Stripping of the membranes
With this procedure, which can be done in the doctor's office, the doctor manually separates the lower membranes of the amniotic sac from the lower part of the cervix. This is done to help release natural prostaglandins and oxytocin, the hormone that stimulates contractions.

Artificial rupture of the membranes
During this procedure, called an amniotomy, the doctor uses a special instrument that resembles a crochet hook. It's gently inserted into your vagina, through the cervix and into the amniotic sac. Your doctor will make a small tear in the sac and the amniotic fluid will come out of your vagina. Uterine contractions often follow. This procedure requires close monitoring, so it's done in the hospital. To avoid the risk of infection, the delivery should be completed within 24 hours.

An amniotomy can't be done if:

the cervix hasn't begun to dilate
the baby isn't positioned headfirst
the baby is positioned too high in the pelvis, which may allow the cord to come out of the vagina with the amniotic fluid
Medication
Labor may also be induced with a synthetic form of oxytocin. It's given intravenously, typically through gradually increasing doses, to produce contractions that are strong and frequent enough to cause the cervix to dilate. The contractions and the baby's heart rate will be continually monitored while you're receiving oxytocin.

If prostaglandin gel is initially used to soften the cervix, oxytocin may be given six to 12 hours later.

Prostaglandin in tablet form (Cytotec, for example) may also be used to induce labor. Tablets are placed in the vagina about every four hours until labor begins.


Benefits
Specific benefits vary, depending on the exact procedure used.
Prostaglandin gel may decrease or eliminate the amount of oxytocin needed for induction. It may also soften the cervix.

Stripping of the membranes is thought to initiate labor, but this hasn't been verified with extensive study.

Artificial rupture of the membranes sometimes shortens the length of labor. This method also allows for the inspection of the amniotic fluid to determine if meconium is present. (Meconium in the amniotic fluid indicates that the baby had a bowel movement and is in danger of inhaling, or aspirating, fecal material into his or her lungs. Steps can be taken after delivery to reduce complications, such as pneumonia, for the baby.) Artifical rupture of the membranes also allows the doctor insert special monitoring devices that can more accurately measure the baby's heart rate and the strength of the contractions.

Oxytocin may activate labor that otherwise wouldn't have occurred.

Risks
There are risks associated with each method of induction as well.
Prostaglandin gel may stimulate excessive uterine contractions.

Cervical dilators may increase the risk of infection.

Stripping of the membranes may cause bleeding (due to a placenta that's abnormally positioned near the cervix) and accidental rupture of the membranes.

Artificial rupture of the membranes may cause infection and trigger the umbilical cord to fall through the cervix.

Oxytocin may cause excessively strong or frequent contractions that decrease the supply of oxygen to your baby, possibly causing fetal distress. Oxytocin may also cause the uterus to rupture.

Postprocedure care
If the induction is successful, postprocedure care is simply normal postpartum care. If it doesn't work, however, the next step will depend on the reason for the induction. Sometimes, it may be possible to continue waiting for labor to begin naturally. In other cases, a C-section may be needed.

Considerations
Consult your doctor about the reason for induction, the benefits and risks for you and your baby, and any other treatment options.