A Foley bulb induction is when a doctor inserts a small balloon into the cervix to help it dilate faster. This procedure is one of several ways to induce labor.
An estimated 23.3 percent of women in the United States had an induced labor in 2012.
In this article, we discuss how a Foley bulb induction works, what to expect, and the possible risks of the procedure.
A Foley bulb induction is a method for inducing labor. It involves inserting a Foley catheter into the cervix to help it dilate so that the baby can pass through the birth canal.
A Foley catheter is a long, rubber tube with an inflatable balloon on one end that a doctor can fill with air or sterile water.
When the balloon inflates inside the cervix, it puts pressure on the cervical cells, helping it dilate and increasing the tissue’s response to oxytocin and prostaglandins.
Oxytocin and prostaglandins are hormones that help to promote labor.
A Foley bulb induction is a safe procedure. There is no evidence of increased risks for infection. Serious complications for the woman and baby are also rare.
There are advantages and disadvantages to this approach, so people should thoroughly discuss the decision to have a Foley bulb induction with their doctor.
The benefits of using a Foley bulb induction include that it is:
- low-risk in most people
- simple to use
- widely available
The typical Foley bulb induction procedure includes the following steps:
- A doctor will monitor the baby’s heart rate for at least 20 minutes.
- They will confirm that the baby is in a head-down (vertex) position.
- The medical team will help the woman move into the lithotomy position, which involves her lying on her back with her legs in special stirrups.
- The doctor will clean the perineal area using a medical solution.
- Using forceps, they will move the tip of the Foley catheter through the opening in the cervix. The balloon will be just beyond the cervix, but outside the amniotic sac.
- They will fill the Foley balloon with about 30 milliliters of sterile water.
- Doctors may tape the Foley catheter to the woman’s thigh to create additional tension.
- The doctor may put more sterile water into the Foley balloon to help the cervix dilate further as time goes on.
The Foley balloon will usually fall out when the cervix has dilated 3 centimeters (cm).
Delivery is usually possible once the cervix is 10 cm dilated and the woman is experiencing frequent uterine contractions.
Doctors should consider a woman’s medical history, the course of pregnancy, and the current health status of the fetus when recommending a Foley bulb induction.
According to a 2018 systematic review, the risks of using a Foley bulb to dilate the cervix are low. Looking at 26 studies and 8292 women, the researchers found that the most common adverse effect was pain or discomfort.
The Foley bulb placement may also stimulate contractions, which can be uncomfortable or painful.
Sometimes, a doctor may recommend a Foley bulb induction if a pregnant woman meets the following criteria:
- over 37 weeks gestation
- older than 18 years of age
- pregnant with one baby
- intact amniotic membranes, meaning the membranes have not ruptured
Women can choose to have an induction — this is called an elective induction. Common reasons to have an elective induction include labor not starting naturally when the baby is due and living far away from the hospital.
Doctors may recommend other methods to induce labor, such as using a double balloon catheter, or Cook cervical ripening balloon. This device is similar to a Foley catheter but has two balloons instead of one.
They may also insert special medications into the cervix to help induce labor. These medications include:
- misoprostol (Cyotec)
- dinoprostone (Prepidil or Cervidil)
A doctor may also give a woman oxytocin intravenously to promote uterine contractions.
A Foley bulb induction is one method of inducing labor. There are many reasons — both medical and elective — why a woman may have a Foley bulb induction.
Induced labor is common, occurring in almost a quarter of childbirths. Foley bulb induction is safe and does not have any negative side effects or risks for the woman or baby.