PROM: Premature Rupture of the Membranes

PROM: Premature Rupture of the Membranes

In the movies and on TV the onset of labor is often depicted with the expectant mother experiencing a big gush of water and immediately thrust into active labor. As exciting as it may be, that scenario very rarely happens. For 90% of women, the onset of contractions will happen first, and then at some point during labor the bag of water will spontaneously rupture or the care provider will manually break the membranes. The other 10% of mothers will have what is called PROM or Premature Rupture of the Membranes. Their bag of water will break BEFORE the onset of labor.

What does that then mean for the pregnant mother? Most patients (90%) enter spontaneous labor within 24 hours when they experience PROM at term. (At term being 37 weeks or beyond.) Once PROM has occurred, there are two avenues to choose from. One is managed care – meaning inducing labor – and the other is expectant management, which means waiting for labor to start on its own. (Please note: I am not including situations in which meconium is present in the water or instances of premature labor in which the woman is less then 37 weeks pregnant in this discussion.) There are pros and cons to both options. The major risk with PROM is intrauterine infection, indicated by a maternal fever. This risk is small (10 %) during the first 24 hours but increases by 40% after that point. It is because of this increased chance of infection that care providers like to see the mother in active labor within that window of time. Since the amniotic sacs acts a barrier to infection, one of the best ways to protect the open bag and avoid infection is to limit vaginal exams which introduce bacteria into the uterus. Another concern is an increased risk of cord prolapse. Since the amniotic fluid is lessened, there is a risk of the cord following between the baby’s head and the cervix which would cause fetal distress. However, the body does continue to produce more amniotic fluid which is why, once the water does break, the mother continues to leak.

Based on my personal experience, and in pursuing further research on this subject, I have found that there are two types of membrane rupture. One is a full-on break of the bag at the cervix or another part of the amniotic sac and another is a tear higher up on the outer bag water, referred to as a “high leak”. There are two layers to the amniotic membranes. The outer bag can rupture and release the small amount of fluid that is accumulated between the layers. In this case the inner bag is still intact, and it’s the inner bag that really counts, in terms of keeping the baby’s space protected from germs. I have seen mothers in this situation classified as PROM who later went on to have the bag fully broken in order to push labor along. So it may be argued that these mothers should not have been considered PROM and put against the clock to deliver within a certain time frame.

There can also be a false positive in diagnosing PROM because of leakage from the outer bag. False positive may be from blood, semen, alkaline antiseptics and sometimes, alkaline urine. Vaginal infections may also raise the vaginal pH, causing a false positive. To test for a leakage of amniotic fluid, Nitrazine paper is placed at the entrance of the cervix. This test is used to indicate the ph balance of the fluid. If it turns dark blue, there is a ph balance of 7- 7.5 or above indicating that there could be an amniotic leak. There are two more conclusive way to diagnose PROM. One very reliable way is to have the care provider (do NOT do this yourself) do a digital examination. The care provider should be able to feel the bag bulging at the presenting part, which indicates that the bag is still full and intact. Another way is to test the fluid from the vaginal pool and do a fern test for detecting amniotic fluid in the secretions. This test is based on a fernlike crystallization of sodium chloride in the amniotic fluid, which can be observed microscopically when the specimen is dried. It is important to remember the possibility of a false positive result from the Nitrizine paper – that way you could request further analysis of the situation to better help you decide on the direction of your care.

Again, this comes back to your care provider’s preference of action and your choice for how to handle PROM. Some care providers are open to and supportive of the ‘watch and wait method’, although usually requiring the mother to be in active labor by the 24th hour after rupture. They will keep an eye on the mother and baby, checking for maternal fever and fetal wellness. Others will want to start induction sooner. For those wishing to go the all-natural route, there are ways to help move labor along: nipple stimulation, castor oil, enema, and acupressure or acupuncture (these last two should only be done by a trained professional.) I also recommend having a conversation with your care provider before the onset of labor about how he/she handles PROM so that you are not negotiating options after the fact.

For those that are not opposed to medication, induction may be a route you choose to take. Labor induction has some benefits in the management of women who experience premature rupture of membranes at term, Cochrane reviewers report. A systematic review of data from 12 studies on nearly 7000 women who had premature rupture of the membranes at 37 or more weeks’ gestation has found a lower risk of maternal infection and neonatal intensive care for women who were induced than for those who underwent spontaneous labor. Newborn infection rates and the incidence of cesarean and assisted vaginal deliveries did not, however, differ between the two groups.

While the timing of your membrane rupture is largely out of your control, at least now you have an understanding of how it is truly determined whether you are experiencing a rupture, as well as how you may wish to proceed should PROM be at hand.

1 Comment
  • dorit
    Posted at 12:52h, 17 September

    I wish I would have read this before my previous birth. what you didnt mention (and I also wish I had known) is another con of inducing and that is that it may cause very strong contractions (level 9-10) without any gradual buildup, and they may not be efficient in dilating the cervix since they are not naturally occuring.

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