Inducing Labor: Why it\’s Necessary and How it Works

pregnant woman discussing with doctor

In a pregnancy that is progressing normally, your body and your baby's secrete the hormone oxytocin, triggering labor. This starts contractions and preps your cervix by thinning and softening it. Induction is an attempt to jump-start this process.

When you're feeling huge and rolling over in bed requires intervention, scheduling an induction like a hair appointment seems like a fabulous idea. More women are scheduling inductions to start the birth process – in fact, the American College of Obstetricians and Gynecologists (ACOG) reports that 20 percent to 40 percent of labors are now induced.

Plus, a recent study seems to indicate that induced birth at 39 weeks has better outcomes for women and children than "waiting it out." But there's a lot to consider before you decide to induce. 

Why do doctors induce labor?

If a baby is showing signs of poor growth or distress or is more than a week or two overdue, he may be healthier if delivered quickly. For mothers with high blood pressure, preeclampsia, uncontrolled diabetes, or certain other health conditions, a medically indicated induction may mean the difference between a healthy delivery and a catastrophe.

"Inductions are getting a bad rap because we're doing too many for no reason, but many times they're an appropriate medical tool," says Kim Gregory, M.D., vice-chair of the Department of Ob-Gyn Women's Health Care Quality and Performance Improvement at Cedars Sinai Medical Center in Los Angeles.

If you're at 41-and-a-half weeks of pregnancy, induction is a clear choice, says Leslie Ludka, a nurse-midwife in Silver Springs, Maryland. Past 42 weeks, odds are your baby will be larger, and that can lead to prolonged labor or complications with your newborn.

How do doctors induce labor?

Doctors have several methods of inducing labor. The one your practitioner uses will depend on a number of factors, such as the readiness of your cervix and your baby's health. Get familiar with the methods below, but remember, there are no guarantees: 

"No one knows how the mother's body will respond until the induction begins," Ludka says. "It's also difficult to anticipate how the baby will respond to labor, whether artificial or natural, until labor begins." You could have a fast, smooth induction – or you could have a prolonged experience.

Method #1: Stripping the membranes

Your health care provider will do a cervical exam, and with her finger, she will separate the amniotic sac from the wall of the uterus. Many women have cramping and spotting after this is done. When the membrane is separated, hormones called prostaglandins are released, and these ripen the cervix by causing contractions. Stripping the membranes during pregnancy can be done only if your cervix is dilated.

Method #2: Ripening the cervix

Before inducing labor, the cervix is assessed by a Bishop Score — a point system of 0-3 on five factors, including how far open and thinned out it is. The higher the score, the greater the chance for a vaginal delivery, while totals under 5 are the biggest risk factor for a C-section. Your doctor will examine your cervix to see how effaced and dilated it is and will check to see if your baby has descended into your pelvis.

Studies show that induced labors are most effective in women whose cervices are ready for labor, so if yours isn't, your health care practitioner may help things along by using one of several ripening agents. These include prostaglandin E suppositories, a prostaglandin-laced gel, prostaglandin on a vaginal device, or a prostaglandin tablet. Some women who go this route go into labor within 24 hours without needing to have any other intervention.

Other tricks used to open your cervix include laminaria (seaweed sticks, which absorb water from the cervix and slowly open it) or a urine catheter bulb (which gets blown up in the cervix and gradually opens it).

Method #3: Rupturing the membranes

If stripping the membranes does not cause contractions, your practitioner may decide to insert an obstetric tool that looks a little like a crochet hook through your cervix to tear a small hole in your amniotic sac. (This technique is also called an "amniotomy.") It mimics what sometimes happens in nature when your water breaks before labor begins.

This procedure can be uncomfortable if you're less than a centimeter dilated, but otherwise it doesn't hurt at all. If labor doesn't begin within 24 hours after your water is broken, your practitioner may then induce you with Pitocin, the synthetic version of oxytocin, or another method to decrease the risk of infection.

Method #4: Pitocin drip

Pitocin is a synthetic form of oxytocin, which is your body's contraction-inducing hormone. It's one of the most commonly used drugs in the United States. For most pregnant women, labor begins in part as a result of higher levels of oxytocin in the blood; your practitioner is aiming to mimic this natural process by administering Pitocin.

If your labor is induced with Pitocin, you will be admitted to the hospital where you will have an IV needle inserted into your arm. It usually takes at least 30 minutes for the Pitocin to kick in, and your practitioner will probably start slowly and monitor your reactions and your baby's response to the drug as it builds in your system. There is no guarantee of rapid labor with Pitocin; still the uterine contractions may be strong, and each contraction may last 1 minute or more. Many women find that the breathing exercises they've practiced for labor help them a good deal during an induced labor as well.

Can I choose to be induced?

Thinking about inducing because your doctor's vacation coincides with your due date or you're just plain tired of being pregnant? According to the Centers for Disease Control, almost 25 percent of all inductions are elective, or not medically necessary. Choosing to induce labor for non-medical reasons is a hot topic among experts and moms alike.

The American College of Obstetricians and Gynecologists doesn't recommend induction for non-medical reasons before 39 weeks. Any earlier, and you risk bringing your baby into the world before she's developmentally ready.

"Induction is a medical procedure that carries risks, so it should be reserved for medical reasons only," says Sabine Droste, MD, associate professor of obstetrics and gynecology at the University of Wisconsin-Madison.

But she concedes there are nonmedical situations when induction is a viable option. "We get patients from outlying rural communities," she says. "They barely made it to the hospital the first time they had a child, and now they're approaching the due date for their second child. Unless I want them to deliver on the highway, that's someone I want to have come in."


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