Overdue baby? Here’s what you need to know about the Foley bulb

Soon after Hunter McGrady had a Foley bulb placed to induce labor with her first child, she posted on Instagram that all women everywhere—pregnant or not—deserve an award. Moms across the internet commiserated… and maybe clutched their wombs a little.

You may not have heard of the Foley bulb or Foley balloon before the Sports Illustrated swimsuit model’s declaration unless you yourself have experienced it—it’s a tool commonly used in labor to encourage cervical dilation. The Foley bulb is sometimes used as an alternative to or alongside medications given to induce labor, like Pitocin (the synthetic version of the hormone oxytocin).

But it can hurt. “Depending on the position of your cervix and how dilated it is at the time of placement, the placement of the Foley balloon can range from being very tolerable to pretty painful,” notes OB/GYN and Motherly’s Medical Advisor Dr. Sarah Bjorkman.

McGrady went on to share that “epidurals get an award, too,” (yep) and that she gave birth to her first child, Hudson Tynan Keys, on June 26. And while she was surprised to become the unofficial spokesperson for the Foley bulb, her story shed some light on a labor technique that might be a little mystifying.

Here’s what you need to know about the Foley bulb, from how it works to how it feels when placed.

What is a Foley bulb?

The Foley bulb or Foley balloon is technically a catheter, which is a long, thin, flexible tube inserted into the body with a small, inflatable balloon on one end. The Foley catheter is most commonly used to empty the bladder when urination isn’t possible, but in labor it’s often employed as a mechanical induction tool, used to encourage the cervix to dilate and to promote contractions.

What does the Foley bulb do?

The Foley bulb works to prep your cervix in two ways:

• By triggering the release of hormones to help soften and dilate the cervix
• By using mechanical dilation—when the balloon is inflated, the uterus contracts against it, helping to open the cervix from the inside

How does a Foley bulb induction work?

Your obstetric provider will likely use a speculum to guide the deflated balloon portion of the Foley bulb through the vagina and into the uterus, or they may place it blindly, using their hand to feel the opening of the cervix and thread the bulb through, notes Dr. Bjorkman.

The balloon will sit inside the uterus—but just outside the amniotic sac housing the baby, which means your water does not usually break with insertion. Once the balloon is placed, just below the baby’s head, your provider will pump the balloon full of saline solution to inflate it to 2 to 3 centimeters in diameter (cue the cramping), in order to help dilate the cervix and prep it for labor.

Depending on the type of Foley balloon used, it can stay inside your uterus for 12 to 24 hours, but it will usually fall out on its own in less than 24 hours because the cervix will have dilated past that 2 to 3 centimeters and won’t hold the balloon in place anymore. “The tail of the Foley will hang out of your vagina, but you can just keep it tucked in your underwear,” says Dr. Bjorkman, “and it’s usually fine to use the bathroom or shower with the Foley in place.”

When and why is the Foley bulb used?

The Foley bulb is the most common mechanical induction technique. In labor, your practitioner may recommend you be induced via the Foley bulb if:

• You’ve reached full-term but didn’t get into labor on your own and your cervix isn’t “ripe” enough
• A complication has arisen and you need to be induced—and your baby is in head-down position and you don’t have any placenta problems (such as placenta previa)
• You need to be induced, but you’re not a good candidate for (or don’t want to use) other induction methods, like medication

What are the benefits of using the Foley bulb induction method?

The main benefit of using a Foley bulb is that it’s highly effective—it simply works. A 2012 study found that after 12 hours of using a Foley bulb, only 6% of women still had an “unfavorable” cervix. And, because it’s a mechanical tool and not a medication, there are no major body-wide side effects.

“They also have lower rates of causing the uterus to contract *too* frequently, and if there are any issues, the balloon can be removed immediately,” notes Dr. Bjorkman. In some settings, you may even be able to get an outpatient Foley, where you can have your balloon placed, be monitored briefly, then go home and come back the next day for further steps.

What does the Foley bulb feel like?

“I always tell patients that your uterus gets irritated when the balloon is in, and it will start cramping or use contractions to try and get the balloon out. If it’s left in for a longer period, your uterus might continue to contract painfully [it wants that balloon out!]—or it might relax and you won’t even notice the balloon is in,” Dr. Bjorkman says.

Initially, when the catheter tube is going in, it can be super painful as your provider manually threads the tube through your cervix.

What are the potential risks of using the Foley bulb induction method?

Because they can be easily removed, Foley bulbs are one of the safest induction methods. “It’s very rare, but one of the risks of any type of induction is that the uterus can contract too quickly, causing fetal distress—but Foley balloons are less likely to cause this than other methods,” Dr. Bjorkman says. After it’s inflated, your provider will monitor your baby with the fetal heart rate monitor to ensure that there’s no stress placed on the baby.

Featured expert:

Dr. Sarah Bjorkman, OBGYN, Motherly’s Medical Advisor

Sources:

Gu N, Ru T, Wang Z, et al. Foley catheter for induction of labor at term: an open-label, randomized controlled trial. PLoS One. 2015;10(8):e0136856. doi:10.1371/journal.pone.0136856

Jozwiak M, Bloemenkamp KW, Kelly AJ, Mol BW, Irion O, Boulvain M. Mechanical methods for induction of labour. Cochrane Database Syst Rev. 2012;(3):CD001233. Published 2012 Mar 14. doi:10.1002/14651858.CD001233.pub2