Induction: Getting Labor Started


What is it? Using interventions to start labor, rather than waiting for labor to start on its own. Most methods either aim to ripen the cervix with prostaglandins (natural or artificial) or aim to start uterine contractions with oxytocin (or pitocin, an artificial oxytocin).

Why would labor be induced? There are several possible reasons. Those nearer the top of this list are cases where the benefits of induction likely outweigh the risks. Those nearer the bottom of this list are more controversial, and the risks are more likely to outweigh the benefits.

  1. If the baby or mother has a severe health condition which makes it riskier to continue the pregnancy than to induce;  severe pre-eclampsia, diabetes with complications, a baby who is not growing well, etc. (For an example of specific medical criteria, click here.) It’s estimated that this rationale for induction only applies to 3% of pregnancies.
  2. Water breaking. If mom is more than 35 weeks pregnant, and it’s been more than 24-48 hours since membranes ruptured, most caregivers recommend induction to reduce risk of infection.
  3. A baby that’s “overdue” – pregnancy lasting over 42 weeks.
  4. If baby or mother has a milder health condition that might mean the benefits of induction are worth examining.
  5. A pregnancy lasting over 41 weeks.
  6. The baby is “too large.” Although this is a common reason for physicians to recommend induction, research seems to indicate that there are not significant benefits to inducing labor.
  7. Convenience or preference. Of the mother, or the caregiver. The risks typically outweigh the benefits.

How common is it? Numbers range radically from hospital to hospital. In Seattle in 2001, amongst the hospitals that would disclose the data, rates ranged from 15-30% of women. (The hospitals that wouldn’t disclose were informally estimated at being as high as 50%.) In the Listening Mothers nationwide survey (2002), 44% of women reported that their caregiver tried to induce labor. 18% cited a non-medical reason as the only reason to induce labor. 16% reported that a combination of medical and non-medical reasons led to the choice to induce.

Will induction start a labor? Your readiness for labor is influenced by many factors, including fetal maturity and cervical readiness. Trying to induce labor can be frustrating and emotionally exhausting if it fails.

Induction is more likely to succeed if your body had already begun to prepare for labor. Ask your caregiver about using a Bishop score to help determine how “ready” your body is for labor. This assessment of your cervix looks at: dilation, effacement, cervical position, cervical consistency, and baby’s position. If these signs are positive (Bishop score >6), you’re “favorable for induction”. If not, it may be possible to wait a few days before inducing, or your caregiver may recommend using cervical ripening agents first before using Pitocin.

What are the risks of induction? Induced contractions may be more powerful, and have a longer duration than non-induced labor, so they may lead to a more painful labor. This increases the chance that pain medication will be used, with the possibility of risks related to the pain medication. The longer, stronger contractions can interrupt blood flow and oxygen to the fetus, and lead to drops in baby’s heart rate, so continuous monitoring is needed.

The induction consent form for a Seattle hospital states that risks may include “a longer labor time, a higher chance of forceps and/or vacuum use during delivery, a higher chance of a cesarean section delivery, more bleeding or infection, a longer hospital stay and longer length of recovery.” For first time labors, inductions increase the risk of cesarean by two to three times.

What can you do about it? If your caregiver has recommended induction, you could consider asking whether it would be appropriate for you to try some natural methods of induction before moving on to medication. These include:

  • Orgasm. If your water has not broken, you could try intercourse: semen contains a small amount of prostaglandin, and orgasm causes oxytocin to flow. If your water has broken, oral or manual stimulation of the clitoris also can lead to orgasm, and thus to contractions.
  • Nipple stimulation releases oxytocin: stroking nipples, using a breast pump, or oral stimulation. Discontinue if contractions come more than every four minutes, or last longer than one minute.
  • Acupressure on spleen 6 point: lower leg, 4 finger-breadths above inner ankle bone. Apply pressure in on-off cycles of 10-60 seconds each for up to 6 cycles.
  • Enema or castor oil. Bowel contractions may stimulate uterine contractions. This isn’t pleasant, so usually only used to avoid medical induction methods.
  • Herbal preparations and homeopathic remedies. Contact a trained practitioner for information.

How your caregiver can help with preparing your cervix for labor.

  • Sweeping the membranes, also called stripping the membranes. Caregiver inserts a finger into the cervix, and separates membranes from lower uterus.
    • Benefits: Increases prostaglandin production.
    • Disadvantages: Uncomfortable, can cause increased risk of infection. May accidentally lead to AROM.
  • AROM: Artificial Rupture of Membranes / Breaking the Bag of Water. During a vaginal exam, the caregiver inserts amniotomy hook through the cervix, and makes a hole in membranes, releasing amniotic fluid.
    • Benefits: Increases prostaglandin production. When used with Pitocin, reduces length of labor compared to Pitocin alone. Painless.
    • Disadvantages: Increased risk of infection. Sets time limit on labor. May intensify contractions. May be harder for baby to change position. Most appropriate and most effective is used in late labor.
  • Prostaglandins. Either a gel (Prepidil) is placed within or around the cervix with a syringe, or a tampon-like insert (Cervidil) is placed inside the vagina with a time-release medication.
    • Benefits: May help the cervix dilate more quickly, which may trigger onset of labor. Improves success of Pitocin induction. The Cervidil insert can be removed if contractions become too strong or frequent.
    • Disadvantages: Can over-stimulate uterus and cause fetal distress. Possible nausea, vomiting, or diarrhea. Gel is difficult to remove.
  • Cytotec / misoprostol. A tablet is placed in the vagina behind the cervix, or given orally.
    • Benefits: More likely to start labor than prostaglandins. Low cost.
    • Disadvantages: May cause excessive, frequent contractions. Not approved by FDA for labor induction; few scientific trials have been done to establish effective dosage, effectiveness, and safety for mother and baby. Risk of uterine rupture, especially in VBAC moms.

How your caregiver can stimulate uterine contractions.

  • Synthetic oxytocin. (Pitocin) Given by I.V.
    • Benefits. Causes uterine contractions and dilation of cervix. (Most effective if cervix is ripened before pitocin begins.) Can be adjusted to adjust the strength and frequency of contractions.
    • Disadvantages: Uterus may become over-stimulated, leading to long, strong, painful contractions. These, in turn, may lead to fetal distress. Requires constant fetal monitoring.

Summary of induction risks. All of the forms of induction can lead to stronger, more painful, and more frequent contractions, which may lead the mother to use pain medications she might otherwise not require. These powerful contractions may also limit oxygen supply to the baby, so increase the risk of fetal distress. Also, due to the uncertainty of due dates, and the variation in the amount of time any given baby requires to reach maturity, early induction carries a risk of causing premature birth. There is a significant increase in the chance of cesarean.

This increased cesarean rate does not seem to lead to better outcomes for babies: a study titled “First Births – A continuous Quality Improvement Project” showed that by reducing inductions in first-time mothers by 22%, there was a corresponding decrease in cesarean birth by 21% with no change in newborn outcomes.

It’s important to clearly discuss these issues with your caregiver. If the induction is being done for convenience, or for unclear medical issues, then the benefits of induction may not outweigh the risks.

Questions to Ask Your Caregiver if Induction is Recommended:

1. Why? What are the reasons why it would be better to deliver the baby sooner?

2.  When? Is this something that needs to happen today? What would happen if we waited a few more days? Another week?

3.  How? Could we start with one of the non-medical options and see if that works?


Compiled by Janelle Durham. For sources, see “Common Variations in Labor”.


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