The Ultimate Guide: Understanding Artificial Rupture of Membranes (AROM) During Labor (2024)
Around 12 days after conception, an amniotic sac forms in your uterus. This amniotic sac will house your baby for the duration of your pregnancy. The amniotic sac is full of water (amniotic fluid), which helps to cushion your baby and the umbilical cord.
At some point toward the end of your pregnancy, your amniotic sac may “rupture.” We usually hear this referred to as your “water breaking”. Sometimes this happens before labor, sometimes it happens during labor, during pushing, and sometimes it doesn’t happen until after your baby is born. If your water doesn’t break on its own, your baby can either be born in the amniotic sac, referred to as “en caul”, or your provider can break your water at some point during labor. This process of your provider breaking your water for you is referred to as “artificial rupture of membranes” (AROM).
There are some pros and cons to allowing your provider to break your water for you. It’s important that you learn about artificial rupture of membranes so you can add your preferences to your birth plan!
What is the amniotic sac and what is its function?
The amniotic sac is a very thin layer of membranes that surrounds your baby for the duration of your pregnancy. The amniotic sac is filled with water, known as amniotic fluid. The purposes of the amniotic sac and amniotic fluid are:
To help protect your baby from injury by providing cushion
To help protect your baby’s umbilical cord from becoming easily compressed
To help regulate your baby’s temperature
Your baby practices swallowing in the womb by swallowing the amniotic fluid
The amniotic fluid helps your baby move around easily, which promotes proper bone development
Amniotic fluid has antimicrobial properties, which helps to protect baby from infection throughout your pregnancy
Amniotic fluid contains proteins, nutrients, vitamins, minerals, and electrolytes that come from you to help support your growing baby
Around 34 weeks of pregnancy is when the amniotic sac will contain the most fluid, about 800 milliliters; that's almost 2 pounds of fluid!
Your amniotic fluid can actually tell you a lot about your pregnancy and baby. While it’s a pretty uncommon and, possibly risky, procedure, some pregnant folks get an amniocentesis at some point during their pregnancy. An amniocentesis is when a long needle is inserted into the abdomen to puncture the amniotic sac and retrieve some of the amniotic fluid. This fluid can be sent for testing to determine:
Baby’s gender
Any chromosomal abnormalities that may be present
Any developmental issues that may be present
What is amniotomy or Artificial Rupture of Membranes (AROM)?
Amniotomy, or artificial rupture of membranes (AROM), is when your provider breaks or “ruptures” your amniotic sac for you.
How is Artificial Rupture of Membranes (AROM) performed?
If you and your provider decide that an amniotomy is best for you and your baby, you can expect your provider to assist you into the lithotomy position. This is where you are on your back and your legs may be in stirrups; the same position you are in for pap smears and cervical examinations.
If labor hasn’t started yet, your provider may place a speculum into your vagina to visualize the amniotic sac. If you are already in active labor, your provider may not even use a speculum; they may just use their fingers to feel for the amniotic sac. They will then use what is called an “amnihook” to puncture a small hole in the amniotic sac. The amnihook looks very similar to a crochet hook.
Once the amniotic sac is punctured, you may feel a huge gush of water or it may just be a trickle.
What can I expect when my provider breaks my water?
While you may experience some cramping/discomfort from the amnihook entering your cervix, the actual rupture of the amniotic sac is painless to you and your baby.
Once the amniotic fluid begins to flow out, your provider will assess the fluid for color and odor. Amniotic fluid should be colorless and odorless (or have a faint earthy, sweet smell)
If the amniotic fluid is brown/green, that means your baby has passed meconium in utero.
It can be normal to have some light bleeding or pink-tinged amniotic fluid, but the fluid should not be predominantly blood.
It is very common for contractions to drastically intensify once your amniotic sac is artificially ruptured.
You can also expect to leak/trickle amniotic fluid for the duration of your labor. Most pregnant folks choose to wear an adult diaper or a menstrual pad.
When and why is Artificial Rupture of Membranes (AROM) performed?
The most common reason for AROM to be performed is to “speed up” labor or to help induce labor. Rupturing the amniotic sac can sometimes help to jump start labor because it is thought that your body produces hormones (like oxytocin) once the amniotic sac is ruptured. If your provider is breaking your water for induction purposes, it is usually paired with another form of induction, like cervidil or pitocin.
The evidence on whether AROM truly speeds up labor is pretty conflicting and seems a bit anecdotal (meaning it’s based on what people observe, not well done studies). In most cases, breaking the waters will cause contractions to intensify, which may give off the perception that labor is progressing. Sometimes, these intense contractions can, unfortunately, make labor unbearable, leading to the need for comfort management (like an epidural), which may or may not slow down the labor process.
Conversely, some studies show that AROM is an effective method of induction.
Sometimes, labor can be pretty long. If you and your provider decide you want to attempt to move things along a bit quicker, they may offer to break your water for you. Like we previously discussed, breaking your water usually causes contractions to drastically intensify (which can be good or bad).
Another reason an amniotomy may be performed is to use internal monitoring. If your labor team is having a hard time tracking the baby's heart rate, they may suggest internal monitoring. This is when an electrode is attached to your baby’s head through your vagina and cervix. This type of monitoring allows your baby’s heartbeat to be monitored continuously, regardless of your position. Internal monitoring also allows, not only the timing and duration of your contractions to be monitored, but also the intensity of your contractions to be monitored.
Learn more about the pros and cons of internal fetal monitoring on our web app here!
Who performs Artificial Rupture of Membranes (AROM)?
Your healthcare provider during labor will be the person who performs the amniotomy. This person will either be an obstetrician (OB) or a midwife.
While your labor and delivery nurse will most likely be present to assist your provider with this procedure, it is not within the nurse's scope of practice to perform an amniotomy.
What are the benefits and risks of Artificial Rupture of Membranes?
Just like with any procedure, having an amniotomy comes with risks and benefits.
Some benefits of consenting to an amniotomy include:
Some evidence shows that breaking the waters may result in a shorter labor
Breaking the waters may cause contractions to become stronger and more regular
Breaking the waters allows your provider to assess the color and odor of your amniotic fluid; giving them the ability to know if your baby has passed meconium in utero
If you need to monitor baby more closely and external monitors won’t work, amniotomy will let you place an internal monitor
Some risks that come along with consenting to an amniotomy include:
Experiencing a quick increase in the intensity of contractions (which could be good or bad)
Losing that “cushion” from the amniotic fluid can possibly cause the umbilical cord to become compressed - Umbilical cord compression can lead to heart rate fluctuations and low oxygen levels.
If your baby is not already in the optimal position for birth, losing that fluid may make it difficult for baby to rotate into a better position
Because the amniotic sac provides protection to baby, there is an increased risk of infection the longer the amniotic sac is ruptured
There is a chance that, along with the flow of amniotic fluid, the umbilical cord could prolapse from the vagina; this is a medical emergency requiring an emergency cesarean section
While rare, there is a condition called “vasa previa” where blood vessels run along the amniotic sac. If there is an undiagnosed vasa previa, there is a chance one of these vessels could be nicked; resulting in severe blood loss to baby (hemorrhage)
Once your water is broken, you tend to be put “on a clock.” After a certain amount of hours in labor with ruptured membranes, your provider will want to start antibiotics and probably offer additional methods of induction.
What are the alternatives to Artificial Rupture of Membranes?
Depending on the reason your provider is offering to rupture your membranes, there are always other options.
Regardless of your situation, there is always the option of saying no. You have the right to refuse any procedure and there is no harm in allowing your amniotic sac to rupture on its own; even if that happens while you're pushing or doesn’t happen until your baby is born.
If you and your provider both want to help speed up a longer labor, but you’re not keen on having your waters broken, ask about other methods of induction. Keep in mind that there are ways to help speed up labor naturally and medical ways, too. You can read more about different methods of induction here.
The Takeaway
At some point toward the end of your pregnancy or during labor, your amniotic sac is likely going to rupture. This rupture of membranes can either occur naturally or artificially. If you opt for an artificial rupture of membranes (AROM), your provider will use an amnihook to puncture a hole in the amniotic sac.
Keep in mind that choosing to do this is totally up to you and it’s wise to educate yourself on this subject prior to going into labor. Just as with any medical procedure, AROM comes with benefits and risks.
As always, Motherboard has all of the evidence based and up-to-date information to help you make the best decision for you and your baby!
🤍 The Motherboard Team
