Premature Rupture of Membranes (PROM)

The sac that surrounds a developing baby performs many functions.  Besides holding the baby in, it keeps infection out. It also plays a part in the turnover and reabsorption of the fluid, mostly contributed to by the fetal urine.  Additionally, the pressure within this fluid collection has a role in development of the baby's lungs.  It's called the amniotic sac, made up of membranes commonly called the "bag of water." All in all, it's a pretty important structure.

So when it pops before the baby is mature, there can be severe danger to both baby and mother, because if fluid can leak out, infection can creep in.

Usually a baby is mature about three weeks before the due date (term is 40 weeks). Anytime the membranes rupture before the onset of labor, obstetricians refer to this as "premature rupture of membranes," or PROM. It is thought that this shouldn't really happen, that infection or impending active labor, or both, probably provoke it. When it does happen, labor usually develops spontaneously, which is dangerous to the premature but probably prudent for a term baby. In many of these cases, the infection that caused the membranes to rupture probably causes the irritation that provokes labor. Infection is no good for a baby, lung disease and meningitis being prime fears with such a situation. And if the membranes rupture unrelated to infection, there is then a route in for bacteria.  It is easy to see that premature rupture of membranes or even leaking membranes is considered a situation that must be addressed without fail.

If rupture of the membranes happens during the mature, later part of the pregnancy, and if labor doesn't spontaneously ensue, then labor can be induced so as to effect delivery before infection becomes severe.  This is because the clock is ticking after rupture of the membranes, the onset of infection of the baby in many cases dependent on time of exposure.  This infection can also be injurious to the mother, possibly endangering her uterus (womb). There are flow sheets that obstetricians follow to manage these cases:

1. If the woman is past 37 to 40 weeks, then induce labor if labor doesn't develop spontaneously.  In this case, attempt to have the baby delivered withing twenty-four hours of PROM.  Although the 24-hour rule is not etched in stone, infection becomes more likely after this time.  Also, it is recommended that the pelvic exams be kept to a minimum as this may drag in infection.  If the baby is at or near term and the mother had already decided against vaginal delivery after a previous Cesarean (VBAC), plans can be made to perform a repeat C-section soon after the PROM.

2. If a woman presents with PROM before 32 to 34 weeks (before six to eight weeks prior to term), management can be conservative, because prompting a delivery may put a premature infant at more risk in the outside world than inside of the uterus. This is only considered, however, if there are no signs of infection. Any infection should establish a plan of delivery no matter how early. As seems obvious, hospitalization, bed rest, and antibiotics are a given in these situations.

3. The time between 32 weeks and 36 weeks presents with a particular gray zone challenge, for this is the zone where risks equilibrate with benefits in weighing whether to deliver or to stand.  The closer one gets to 36 to 37 weeks, the less concern there is of devastating prematurity complications.  Back the other way, the closer to 32 weeks one gets, the scarier the situation, and a doctor may go to some extremes in trying to actively prevent labor. Once again, all of these scenarios involve the use of antibiotics to prevent infection while a little more time is bought.

If delivery can be prevented for 48 hours, there is time for steroids to be given to the mother which will help to mature the baby's lungs.  But this protocol is only useful before 34 weeks.

Obstetrics is a natural specialty, because things happen naturally. One becomes pregnant, goes into labor, then has a baby.  Simple. But then there are the rest of us, presenting situations that also make Obstetrics a thinking doctor's specialty. There's so much at stake. Two lifetimes.

So important is management of PROM, that the obstetrical literature has a lot of space dedicated to it in the journals. Protocols are constantly changing as we develop better antibiotics to prevent or ameliorate infection, better medications to treat immature lungs, and better Neonatal ICUs to lower the age limits of survivability in the premature.  Pediatrics and Obstetrics work together like no other partnership of specialties to enhance the quality of life for those at risk.

Q & A: I feel as if I've had an unbelievable amount of discharge over the last month. (I'm 8 months pregnant today.) I've resorted to using pantiliners but I think their use has resulted in a yeast-like infection. My midwife has suggested stopping the use of the pantiliners and just allowing it to "flow" and then "air out," but I'm uncomfortable and am already changing my underwear numerous times per day! I know that the heat has aggravated the situation and when I'm home I try to go without anything; but being a busy working woman I don't have that option every day! Any suggestion?

Me? I'm hoping that all you have is a harmless discharge, but please excuse my using your question to emphasize that whenever a patient calls to complain about a discharge that is out of the ordinary--like your "unbelievable" discharge, I always want to evaluate that patient for Premature Rupture of the Membranes (PROM). It's too important to blow off. And if all I find is bacterial vaginosis or yeast, then I'm obligated to treat it since it is felt to cause the very thing I would be evaluating you for--PROM. Yes, yeast infections are common in pregnancy, but you shouldn't be changing undergarments several times a day. And if it is yeast and PROM has been ruled out with a simple exam, then you should be screened for gestational diabetes, which can cause nagging, repetitive yeast infections but also severe complications for the pregnancy.

One of the most serious complications of pregnancy is PROM. This can happen with infection, preterm contractions, or for unknown reasons. One of the infections that has been implicated is the Group B beta-hemolytic strep that 10% of all women are carriers for. Lately such seemingly harmless infections like bacterial vaginosis (as mentioned above) and the sexually transmitted Trichomonas have been investigated as possible causes, too.

The reason rupture of membranes before term is so serious is because when it happens before a baby's lungs mature, a premature birth can result in a baby being placed on a ventilator. If fluid can leak out, then bacteria can get in. Since the vagina, like other mucous membranes, is loaded with bacteria, a baby can get infected and suffer severe complications as a pre-term newborn.

PROM is a real thinking dilemma for the obstetrician. Certainly if it were to happen after lung maturity (at or past 37 weeks), then delivery via induction or, if indicated, C-section, is prudent. The times from 35 to 37 weeks is a gray zone. But before 35 weeks is problematic. Delivery will certainly bring a baby into the outside world before the lungs are ready. Ventilators, although life-saving, can really bang up the lungs of a newborn. The benefit outweighs the risks, but the risks are there nonetheless. So most obstetricians will try to keep the baby in the uterus to try to gain some lung maturing. Steroids, usually given to the mother before 34 weeks, will hasten lung maturity.

PROM before 30 weeks is a very hazardous complication. Hospitalization, steroids, bed rest, and antibiotics are the treatment. But if the membranes don't seal back (and that is unlikely, especially with a brisk leakage), then it's only a matter of time before infection calls the obstetrician's hand. Also, "dry" environments can impair the growth of the baby's lungs while trying to get them to mature--this can be a real "chase-your-own-tail" phenomenon.

The bottom line is that the amniotic sac is a barrier, protecting the baby while holding in fluid (mostly fetal urine) that helps with lung growth. A leak or bursting of these membranes will allow fluid out and can allow infection in. Or, the PROM may have occurred because of an infection already there. In any event, PROM is a complication whose outcome is directly related to how far along the pregnancy is. The fact that the American College of Obstetricians and Gynecologists has changed protocols for PROM many times over the last two decades underscores the fact that we still don't have the perfect management answers.

In your situation and anyone like you: You need an evaluation to rule out PROM. A vaginal smear can do this as well as diagnose bacterial vaginosis, yeast, or other culprits that cause discharge. It may be that you have just a hormonal discharge, but the microscope can make that call, too. The fact that you've had the problem for a month probably speaks against PROM, because it would've caused mayhem long before now. But stranger things have happened, so nothing should be taken for granted.