Understanding How Labor Induction Works
Many people imagine the start of labor as something sudden, like their water breaking or strong contractions kicking in right away. In reality, the process can be different for everyone, and sometimes labor does not begin on its own. Medical teams may use labor induction, which involves medical techniques to start uterine contractions before natural labor begins, as a common part of modern obstetrics to ensure safe management of pregnancy and childbirth.
With over one in five pregnancies involving induced labor, understanding why and how labor induction happens is important for parents and families. Induction can change the original birth plan, especially regarding home births or the timing of vaginal delivery. Patients should learn about the reasons for induction, the available methods, and what to expect each step of the way to support the best health outcomes for both mother and baby.
Common Reasons for Inducing Labor
Doctors or midwives may start labor for several medical reasons. Sometimes, being almost two weeks past the expected due date prompts induction because the placenta may not work as well after this time. If the water breaks but contractions do not begin on their own (called spontaneous labor), providers may start labor to reduce risks.
Other reasons for induction include health concerns like infections in the uterus, low levels of amniotic fluid, high blood pressure, or issues with the placenta such as partial or complete detachment from the uterine wall. Healthcare providers check the cervix through a cervical examination, looking at effacement (how thin it is), dilation (how open it is), cervical length, and cervical consistency to assess readiness for labor. Providers often use a Bishop score to guide decisions.
Main Induction Techniques
Cervical Stretch and Membrane Stripping
A doctor or midwife may perform cervical stretch and membrane stripping, often called a stretch and sweep, to help bring on labor. In this process, the provider gently inserts a gloved finger into the cervix and carefully moves their finger in a circle to separate the thin membranes connecting the amniotic sac to the uterine wall. This maneuver encourages the natural release of prostaglandins, which are hormones that help the cervix become softer and can stimulate the onset of uterine contractions.
During this procedure, some may experience discomfort or a short period of pain, but it is generally brief. If the cervix is already a bit open, the provider may gently stretch it using two fingers, which can improve the effectiveness of the sweep.
While the procedure is usually discussed around week 38 of pregnancy, not everyone chooses to have it; some may try this method at every appointment, while others prefer to avoid it altogether. The main purpose is to possibly prevent the need for more medical forms of induction later, especially for those who wish to avoid medications or are concerned about going past their due date.
Cervical Balloon Catheter (Foley)
Doctors often use the cervical balloon catheter, commonly referred to as the Foley catheter, as a mechanical way to get the cervix ready for labor. During this procedure, a doctor inserts a thin, flexible tube with a deflated balloon at the end into the cervical canal. Once in place, the provider fills the balloon with saline until it is about two or three centimeters across. This steady pressure helps the cervix stretch and slowly open, making it easier for labor to begin.
The balloon does not trigger strong contractions on its own. Providers mostly use it to help the cervix ripen without relying on hormone medications, particularly for people who cannot use certain drugs or who had side effects in the past.
The catheter is inserted in a hospital or outpatient setting, and staff monitor patients for a short while to check that the process is going smoothly and the baby’s heart rate remains normal. Once the device is in place, the person can often go home for 12 to 24 hours or return sooner if labor starts or the balloon falls out—a sign that the cervix has dilated enough.
Providers often use this method as the first step if hormone medications are not an option. If labor does not progress after the balloon comes out, the care team may consider another induction method, like prostaglandins or breaking the water.
Hormone Medications to Soften Cervix
Healthcare providers commonly use hormonal drugs called prostaglandins to soften, thin, and open the cervix—a process known as cervical ripening. Synthetic prostaglandins are available in several forms, each with different uses and benefits.
- Gel: Providers place the gel near the cervix using a small applicator. The gel slowly releases the hormone, encouraging changes in the cervix.
- Vaginal Insert (Cervidil): Providers place a small flat tab with a string near the cervix and leave it to work.
- Oral or Buccal Tablet (Misoprostol): Patients take this by mouth, dissolve it under the tongue, or place it inside the cheek. Some people also receive misoprostol vaginally, especially if they are already experiencing leakage of amniotic fluid and providers want to avoid repeated vaginal exams. Providers use both oral misoprostol and vaginal misoprostol based on individual needs.
Prostaglandins effectively prepare the cervix for labor. However, these drugs can make contractions too frequent or intense, which can put stress on the baby. Because of that, staff closely monitor patients in a hospital or clinic. Providers may remove the prostaglandin agent or give medication to calm the uterus if needed.
This method is particularly helpful for those whose cervix is not yet soft or open. The medication can help avoid a cesarean birth by making later steps, like an oxytocin drip, more successful.
IV Hormone Drip (Synthetic Oxytocin)
Providers frequently give IV synthetic oxytocin, known by the brand name Pitocin, to make contractions stronger and more regular during induction. The body naturally makes oxytocin, but the synthetic version allows healthcare teams to control the timing and strength of contractions.
Staff provide Pitocin through an intravenous (IV) line, generally after the cervix has been softened with prostaglandins or has started to dilate for another reason. Providers typically avoid using oxytocin as the first or only induction method because it can raise the risk of needing a C-section if given when the cervix isn’t ready. Once started, staff closely watch contraction patterns and monitor the baby’s heartbeat to ensure safety.
Care teams adjust the amount of oxytocin depending on how strong and regular the contractions become. Some people respond quickly, while others may need a gradual increase in the medication. While this method is effective for starting or maintaining labor, it always involves close monitoring to catch any problems, such as too many contractions or drops in the baby’s heart rate.
Artificial Breaking of Water (Amniotomy)
A medical provider may use artificial breaking of the water, or amniotomy, as a physical technique to jumpstart or speed up labor. During this procedure, the provider uses a slender, sterile instrument, which somewhat resembles a crochet hook, to carefully make a small hole in the amniotic sac. This causes the amniotic fluid to leak out.
Providers usually perform an amniotomy when the cervix is already partially dilated and softened. It can be a helpful step during induction or in combination with other methods—such as an oxytocin drip—to keep labor progressing. Staff perform this procedure in a hospital to monitor both patient and baby, as there are risks like the umbilical cord slipping into the birth canal (cord prolapse) or an increased chance of infection once the protective sac has been broken.
Labor typically needs to continue moving forward after the water is broken, because there is no longer a barrier keeping bacteria out of the uterus. Continuous observation helps staff catch any problems early and respond quickly if needed.
Possible Risks Linked to Labor Induction
Labor induction carries several possible risks that care teams and families need to discuss. Some serious complications that can occur, though rare, include heavy vaginal bleeding after birth and uterine rupture. These conditions require urgent medical attention and can impact both the mother and baby.
Some research shows that inducing labor around 39 weeks may actually lower C-section rates, lower infant deaths, and reduce the risk of high blood pressure disorders. Still, outcomes can vary, and having an informed conversation with providers is important.
Other risks include uterine hyperstimulation (tachysystole or hypertonus), which may lead to changes in the baby’s heart rate, fetal complications, and higher chances of postpartum hemorrhage or placental abruption. There may also be differences in NICU admissions for babies born after labor is induced compared to those born after spontaneous labor.
Situations When Induction Is Not Advised
Providers avoid starting labor with medicine or other methods in certain situations. If a woman has had a previous C-section or major surgery on her uterus, especially when considering a vaginal birth after a Cesarean (VBAC), the risk of uterine tearing is higher. This is known as a scarred uterus and raises safety concerns.
Induction is also not suitable if the placenta is covering the cervix (placenta previa), as this blocks the baby’s way out. If a woman has an active case of genital herpes, starting labor can make it easier for the baby to become infected during birth. When the baby is lying in a breech position (bum down) or sideways in the uterus, providers usually do not suggest induction since it can increase risks for both mom and baby.
Options for Starting Labor Naturally
People commonly try several natural methods to help start labor, although scientific support for most of these is limited. Sexual intercourse near the due date may help because semen contains natural prostaglandins, which can soften and prepare the cervix for labor. Many suggest this method because it is generally safe for most pregnancies, but not all experts agree on its effectiveness.
Midwives might use a “stretch and sweep,” which involves a gentle internal exam to help separate the membranes from the cervix. This process can release hormones that may encourage labor to begin. The expectant person and their care provider decide whether to try this technique.
Some midwives offer a “labor cocktail,” which often includes ingredients like castor oil, verbena oil, almond butter, and apricot juice blended together. The castor oil in the cocktail stimulates the bowels, which can sometimes trigger contractions.
While many believe it is safe and some midwives say they have seen good results, no specific published research exists on how much to use or whether it is safe for everyone. Possible side effects of castor oil include upset stomach, vomiting, and diarrhea, which can make some care providers hesitate to recommend it.
Some traditional and Indigenous midwives use certain herbs, such as blue cohosh. Care providers use blue cohosh tea very cautiously and only under supervision, as it can have strong effects and is not proven to be safe for all women.
Some people try acupuncture as a traditional method. Some studies suggest it may help the cervix soften and prepare for labor. Many find it gentle and low-risk, especially when a professional familiar with pregnancy care performs it.
Care providers sometimes recommend nipple stimulation, either by hand or with a breast pump. Stimulating the nipples causes the body to release oxytocin, the hormone responsible for making the uterus contract. In some cases, this can help start or strengthen labor contractions, particularly if labor has slowed down or the water has already broken without strong contractions following.
Other home remedies include walking, eating spicy food, or drinking herbal teas. Many pregnant people try these, although little solid evidence shows they consistently lead to labor. Discuss all these options with a trusted healthcare provider before trying anything, as not every method is appropriate for every pregnancy.
