Premature Rupture of Membranes (PROM)

What is premature rupture of membranes (PROM)

As you approach your due date, your body prepares for childbirth. The amniotic sac covering and protecting your baby breaks open prior to labor and delivery, leading to the amniotic fluid gush out or leak (the water breaking) ^[1]. It is known as premature rupture of membrane or PROM when occurring after the 37th week of gestation, but before you reach full term ^[2]. A premature rupture of membrane often leads to early labor and is associated with various complications related to a preterm delivery.

Prolonged rupture of membranes

A prolonged rupture of membranes occurs when labor starts over 18-24 hours after the water breaks ^[3].

Preterm premature rupture of membranes (PPROM)

When the premature rupture occurs before the 37th week of pregnancy, it is referred to as preterm premature rupture of membranes or PPROM ^[4].

What causes premature rupture of the membranes and PPROM

As the pregnancy gradually comes to term, the amniotic membrane may naturally become weak due to stretching and thinning in preparation for childbirth ^[5], leading to PROM. However, it is often difficult to determine the exact causes. Some of the common risk factors of PPROM include:

Infectious conditions affecting the vagina, cervix, uterus or amniotic sac ^[6]
Sexually transmitted diseases like gonorrhea and chlamydia
Vaginal bleeding, especially in the second and third trimesters
Lung diseases in pregnancy ^[7]
Cervical examination or surgery such as a cerclage ^[8] or some diagnostic procedures like amniocentesis ^[9]
A history of PROM, PPROM or a preterm delivery
A habit of heavy smoking (more than 10 in a day)
Accident or trauma anytime during pregnancy ^[1]

What are the signs and symptoms of premature rupture of membranes

It is not always possible to detect a rupture of membrane immediately as the symptoms are not always easily noticeable. However, in most cases women experience:

Sudden gush of fluid leaking from the vagina ^[10]
A constant wetness that is different from the normal discharge or leaking urine
Pelvic pressure without contractions ^[4]

How do you know if you are leaking amniotic fluid

It is common for women to mistake the leaking amniotic fluid for urine, especially if it is a slow leakage. One useful way of making sure whether you have a ruptured membrane is to use a pad as soon as you notice a wetness. Then you can take a look at the discharge and smell it because amniotic fluid is colorless and smell different than urine as it has a somewhat sweet smell ^[6]. The fluid may also contain a little white or pinkish mucusy discharge ^[11].

Warning signs

Preterm PROM may also increase your chances of developing certain infectious conditions, including chorioamnionitis. Make sure to contact your physician as soon as possible if you experience symptoms like fever and abdominal pain or notice a strong or foul smelling vaginal discharge ^[12].

How is premature rupture of membranes diagnosed

Apart from performing a thorough physical examination and checking your medical history, your doctor may also perform the following:

pH test and nitrazine test to check the pH level of the fluid discharge to make sure if it is amniotic fluid ^[10]
Performing an ultrasound to assess the amniotic fluid volume depending on your gestational stage ^[13]; extremely low fluid levels (oligohydramnios) might indicate amniotic fluid leakage
Injecting a blue dye into your amniotic fluid using amniocentesis, and checking if the blue color is detectable in the vaginal discharge, indicating a leakage ^[14]

Digital pelvic examinations are usually avoided unless necessary as they may further increase the chances of infection, especially if immediate labor and delivery are not anticipated ^[12].

Your doctor may also perform an amniocentesis to check for any sign of infection in the uterus ^[1]. In case of PROM, procedures like a fetal ultrasound and a nonstress test may also be used to assess the overall fetal health, and find out if an immediate delivery is required ^[15]. An amniocentesis may also come useful to determine the fetal lung maturity ^[16].

Premature rupture of membranes differential diagnosis

Common differential diagnoses include leaking urine due to pressure from the baby ^[17] and discharge due to some other condition such as bacterial vaginosis ^[18].

How is a premature rupture of membranes treated

The higher the gestational age at the time of PROM, the lower are the chances of complication in both the mother and baby. So, the management of ruptured membranes depends on how early in pregnancy it is occurring ^[14]. Once a rupture is diagnosed, your doctor is likely to keep you under observation for some time to assess the severity of the condition and evaluate the necessity and safety of inducing labor. In some rare instances, the amniotic sac may repair the rupture to stop the leakage, especially if the damage is at a higher point in the sac, so the pregnancy can continue to term, followed by a natural birth ^{[16, 19]}.

In 90% of women with rupture of membranes beyond week 37, the onset of labor comes within the next 24 hours ^[4]. However, immediate induction of labor may sometimes be needed to stop infections from spreading to the baby. In any case, PROM after the 37th week is followed by labor and delivery as premature babies born at this stage have excellent survival rates without any long-term complications ^[20].

Prophylactic antibiotic treatment ^[21] (commonly using erythromycin ^[22]) may be necessary in case of infections like a GBS, chorioamnionitis and genital herpes to prevent life-threatening complications like neonatal sepsis. Researches have also shown these antibiotics to increase the latency period (the time period between the membrane rupture and beginning of labor) ^{[23, 9]}.

Preterm premature rupture of membranes (PPROM) treatment and management

Although labor usually follows a preterm PROM within 24 hours, it may take several days for the contractions to start, especially if it is a slow leak, or there are no infections present ^[1].

PPROM, especially before the 34th week of gestation, usually requires close monitoring along with bed rest and/or pelvic rest ^[12], as it is preferable to try and continue the pregnancy for as long as possible to increase the baby’s chances of survival.

Corticosteroids may be used to accelerate the fetal lung maturity ^[24] in preparation for a possible premature delivery. They are also believed to help in the management of certain neonatal complications ^[9]. It may be possible to carry your baby to full term even with a second trimester PPROM in some rare cases ^[1].

Preterm PROM complications

In addition to significantly increasing your risk of giving birth to a premature baby, it also makes you more susceptible to chorioamnionitis, a potentially life-threatening infection affecting the amniotic membrane and fluid ^[25]. Other complications associated with PROM include higher chances of having a c-section (as most babies remain in a breech position at the time of PROM), placental abruption, miscarriage and serious post-partum infections like endometritis ^[5].

Complications in the baby

A rupture of membranes in the mother can heighten the risks of complications like umbilical cord compression, respiratory distress syndrome, and intraventricular hemorrhage in the baby after birth ^[26]. Severe cases may also lead to prenatal fetal death ^[9].

Is it possible to prevent PROM

Prevention is often not possible as the exact causes responsible for it usually remains unknown. However, recent studies have suggested an ascorbic acid deficiency to be a risk factor of PROM. Taking vitamin C supplement regularly after the 20th week has been shown in a study to reduce the chances of developing PROM by helping maintain the chorioamniotic membranes.

Pregnancy after PPROM

Having PPROM once makes it 21%-32% likely that you will have it again in a subsequent pregnancy ^[27].

How common is PROM

PROM has a considerable incidence, occurring in around 10% of all pregnant women. Preterm premature rupture of membranes, on the other hand, is diagnosed in about 2% of all pregnancies ^[10]. Studies show approximately 1 in every 4 preterm births to result from PPROM ^[5].

Premature rupture of membranes ICD-9 and ICD-10 codes

The ICD-9-CM code used for PROM is 658.1 ^[28], while its ICD-10 code is O42 ^[29].

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