Induced labor is the stimulation of uterine contractions before they occur spontaneously. Induction is on the rise — in fact, the rate of induced labor doubled between 1989 and 1997, according to the National Center for Health Statistics. A 1999 report by the American College of Obstetricians and Gynecologists (ACOG) says that up to 15 percent of all deliveries are induced. However, ACOG advises that the benefits of inducing labor should be carefully weighed against the possible risks for mother and child before undertaking the procedure.
According to ACOG, some of the most common reasons for labor induction include:
- Post-term pregnancy (two weeks or more past your due date)
- Placental abruption
- Chorioamnionitis (infection of the membranes enclosing the amniotic fluid)
- Premature rupture of membranes
Other reasons for induction of labor are more logistical. For instance, if you live very far from your hospital or if you're at risk of rapid delivery, your doctor might decide to induce your labor after carefully weighing the risks versus the benefits. There is also an increase in women wishing to schedule labor for convenience. For instance, scheduling delivery around a move, a trip, or work. But in general, most doctors will not induce a woman as a matter of convenience.
How Is Labor Induced?
Before you can be induced, your cervix must be "ripe," or ready for labor. If the cervix isn't ripe, mechanical dilators and synthetic prostaglandins can help. Other methods include continuous intravenous oxytocin drip, and administration of the hormone relaxin. However, the safety and effectiveness of these two methods are unclear, according to ACOG.
Once your cervix is ready, labor can be induced by a doctor administering oxytocin, misprostol, or mifespristone. Oxytocin is the most commonly used labor-stimulating agent. Other methods of stimulating labor include nipple stimulation, stripping the amniotic membranes (amniotomy), or rupturing the amniotic membranes manually with a sterile hooked instrument (also called artificial rupture of membranes, or "breaking the water").
Artificial rupture of membranes is generally painless. It's usually very effective at triggering spontaneous labor, but in some cases spontaneous labor doesn't begin for a long while, or at all. That's why oxytocin is often given to help with the induction when your membranes are ruptured artificially.
Stripping of membranes is a bit different. In this case, your bag of waters is manually separated from your cervix. According to ACOG, this procedure results in more reported instances of spontaneous labor and fewer inductions in women who are post-term.
Nipple stimulation is also not a certain method of inducing labor, but it appears to work in some instances because it can trigger the release of naturally occurring oxytocin in your body.