Induced Labor: Reasons, Methods, How Long It Takes and What to Expect

Induced labor is labor your provider starts with medicine or a procedure before it begins on its own, usually because waiting has become riskier than delivering, and it can take a few hours to more than a day.

Being told you will have induced labor brings up questions fast. Why now? What will they do? How long will it take, and will it hurt more?

This guide covers the medical reasons, elective induction at 39 weeks, induction at 37 weeks, the Bishop score, each method, the timeline, pain relief, risks and questions to ask.

What Is Induced Labor?

Cleveland Clinic defines labor induction as a provider starting labor, or moving a stalled labor along, with medication or other methods such as breaking your water. It warns against trying to induce labor yourself with medications or supplements. For what the evidence says about walking, dates and other home tricks, see how to induce labor.

Medical Reasons Doctors Induce Labor

Most inductions happen because the risks of continuing the pregnancy have become greater than the risks of delivery. Mayo Clinic and Cleveland Clinic list these common reasons:

• Going past your due date: Mayo Clinic lists labor that has not started one to two weeks after the due date, and says a pregnancy at 42 weeks from the first day of the last period is called postterm. Cleveland Clinic notes the placenta may work less well after 41 weeks. See 41 weeks pregnant for what monitoring looks like then.
• Your water breaks but labor does not start: also called premature rupture of membranes (Mayo Clinic, Cleveland Clinic). Read more about water breaking.
• High blood pressure or preeclampsia: gestational high blood pressure and preeclampsia are both on Cleveland Clinic’s list.
• Diabetes: gestational diabetes or diabetes that started before pregnancy (Mayo Clinic).
• Growth concerns: fetal growth restriction, when your baby is not growing as expected (Mayo Clinic, Cleveland Clinic).
• Low amniotic fluid: called oligohydramnios (Mayo Clinic, Cleveland Clinic).
• Placenta problems: such as placental abruption, when the placenta starts to separate from the uterus (Mayo Clinic).
• Infection in the uterus: chorioamnionitis (Mayo Clinic, Cleveland Clinic).
• Your history: Cleveland Clinic lists a history of very fast labor, a past stillbirth or past childbirth complications.

StatPearls, an NIH clinical reference, sums up the principle: delivery is considered when the outcome for the parent, the baby or both is expected to be better than waiting for labor to start on its own.

Elective Induction at 39 Weeks and the ARRIVE Trial

An elective induction is one done without a medical need. Mayo Clinic says the pregnancy should be at least 39 weeks before an elective induction, for example for someone who lives far from the hospital or has had fast deliveries.

Much of today’s discussion about 39-week inductions comes from the ARRIVE trial, published in the New England Journal of Medicine in 2018. It enrolled 6,106 low-risk first-time mothers and compared planned induction at 39 weeks with waiting for labor. According to the American College of Obstetricians and Gynecologists (ACOG) practice advisory on the trial, the cesarean rate was 18.6% with induction versus 22.2% with waiting, and high blood pressure disorders of pregnancy were less common with induction (9.1% versus 14.1%).

Per the same advisory, the main measure of serious problems for babies did not differ significantly between groups. ACOG concluded it is reasonable to offer induction at 39 weeks to low-risk first-time mothers, as a shared decision that reflects your values and preferences and what your hospital can support.

Mayo Clinic adds that low-risk people may choose induction at 39 to 40 weeks, and that this lowers the risk of stillbirth, a large baby and pregnancy-related high blood pressure. The trial studied low-risk first-time mothers only, so ask your provider how it applies to you. Our 39 weeks pregnant guide covers what else happens that week.

Reasons Doctors Induce Labor at 37 Weeks

Doctors induce labor at 37 weeks only when there is a medical reason. ACOG’s committee opinion on medically indicated late-preterm and early-term deliveries discourages delivery before 39 weeks without a medical or obstetric reason. It equally says not to wait for 39 weeks when there is a medical reason to deliver earlier.

Conditions that can lead to an induction around 37 weeks include:

• Gestational high blood pressure: StatPearls gives 37 weeks as an example of delivery timing for gestational hypertension.
• Preeclampsia: timing depends on how severe it is. StatPearls notes that preeclampsia with severe features may mean delivery as early as 34 weeks.
• Low amniotic fluid: StatPearls gives 36 to 37 weeks as an example timing for oligohydramnios.

ACOG stresses that timing should be individualized, weighing the risks to you and your baby of delivering now against the risks of continuing. If an induction is recommended at 37 weeks, it is fair to ask what the reason is and what waiting would mean.

The Bishop Score: Is Your Cervix Ready?

Before an induction, your provider checks how ready your cervix is. Cleveland Clinic explains that the Bishop score rates five things during a cervical exam and adds them up to a total from 0 to 13:

Cleveland Clinic says a score of 8 or more is favorable, meaning an induction has a better chance of ending in a vaginal birth, while a score of 6 to 7 is a judgment call and 5 or less means the body is not yet prepared. StatPearls calls a score under 8 unfavorable, which is when cervical ripening is mainly used.

Cleveland Clinic notes the score is only an estimate: some people with low scores have successful inductions and some with high scores do not.

How Labor Is Induced: The Main Methods

Your provider chooses methods based on your Bishop score and your health, and often combines two or more.

Mayo Clinic notes oxytocin is less effective for ripening the cervix than for speeding up labor that is already underway, which is why a firm, closed cervix is usually ripened first with medicine or a balloon. Your care team monitors your contractions and your baby’s heart rate throughout.

How Long Does an Induction Take?

There is no fixed answer. Cleveland Clinic says some people respond within hours while others take longer, and that most reach active labor (about 6 centimeters) within 24 hours. Mayo Clinic says labor may start within minutes to several hours, depending on how ripe your cervix is, the method used and how your body responds.

ACOG guidance gives a sense of how patient the process is meant to be. Its ARRIVE practice advisory says a failed induction should not be called until oxytocin has been given for at least 12 to 18 hours after the water is broken, and that the early (latent) phase can last up to 24 hours or longer. Mayo Clinic describes a failed induction as no vaginal delivery after 24 or more hours. Pack for a possibly long stay with our hospital bag checklist.

What Induced Labor Feels Like and Pain Relief Options

Each step feels different. Cleveland Clinic describes a membrane sweep as mildly uncomfortable, with possible cramping or spotting afterward. Breaking the water is not painful, though it may feel like a pull or pop followed by a gush or trickle of warm fluid.

Cleveland Clinic says induction medications can cause strong pain, similar to very intense menstrual cramps. Oxytocin is given at a steady rate that is raised gradually to produce regular contractions, per StatPearls. For a closer look at the sensation, see what contractions feel like.

Your pain relief options are the same as in any labor. Cleveland Clinic says an epidural is the most common option, and if you already have one you may feel little pain. A doula can offer comfort measures and company through a long induction.

Risks and Benefits of Labor Induction

Induction is recommended when waiting carries more risk, but it has risks of its own. Mayo Clinic and StatPearls describe these:

• Failed induction: if labor does not progress, the next step may be another induction attempt or a cesarean (Mayo Clinic).
• Contractions that are too frequent: StatPearls calls this uterine tachysystole: more than five contractions in 10 minutes. Mayo Clinic says this can lower your baby’s oxygen supply and heart rate, so your team watches closely.
• Infection: some methods, such as breaking the water, may raise the risk of infection for you and your baby (Mayo Clinic).
• Uterine rupture: rare but serious, usually along a scar from a past cesarean or uterine surgery (Mayo Clinic).
• Bleeding after birth: induction can raise the risk that the uterus does not contract well after delivery, which can cause heavy bleeding (Mayo Clinic).

A failed induction can end in a cesarean, but in the ARRIVE trial, low-risk first-time mothers induced at 39 weeks had a lower cesarean rate than those who waited (ACOG). Mayo Clinic notes that induction most often leads to a vaginal birth.

Induction is not an option for everyone. Mayo Clinic and StatPearls list situations such as a prior classical (vertical) cesarean incision or major uterine surgery, placenta previa, umbilical cord prolapse, a baby lying sideways or breech, and active genital herpes.

Questions to Ask Your Provider Before an Induction

ACOG emphasizes shared decision-making for inductions. These questions help you understand your plan:

• What is the medical reason for my induction, and what happens if we wait?
• If there is no medical reason, can we wait until at least 39 weeks?
• What is my Bishop score, and will I need cervical ripening first?
• Which methods do you plan to use, and in what order?
• How long do you expect this to take, and when would you call it a failed induction?
• What are my pain relief options, and when can I have them?
• What would lead you to recommend a cesarean?

If labor starts on its own before your scheduled date, call the labor unit and follow their instructions.

Related Betteroo Guides

• full term pregnancy
• How to Induce Labor
• 40 Weeks Pregnant
• Early Labor vs Active Labor
• Signs Labor Is 24 to 48 Hours Away
• Preeclampsia
• Signs of Leaking Amniotic Fluid

When to Call Your Doctor or Midwife

Whether or not your induction is scheduled, MedlinePlus advises contacting your doctor or midwife in late pregnancy if any of these happen:

• Your water breaks: a gush or a steady trickle of fluid.
• You have any bleeding.
• You notice a decrease in your baby’s movement.
• You start having regular, painful contractions: or they match the rule your provider gave you.
• You have a fever, chills or pain when urinating.
• You have headaches or changes or blind spots in your vision: which can be signs of high blood pressure problems such as preeclampsia.
• You have chest pain or difficulty breathing.
• You have significant swelling and weight gain.

Heavy bleeding, chest pain, trouble breathing, a seizure or a severe headache with vision changes need help right away: call 911 or go to the nearest emergency room or labor and delivery unit. This article is general education, not medical advice.

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