MEDICAL MANAGEMENT OF PROM
Article by Paul T Wilkes, MD, Assistant Professor, Obstetrics & Gynecology,
University of Nevada School of Medicine
Synonyms and related keywords: spontaneous rupture of membranes in the premature
patient, preterm premature rupture of membranes, prolonged rupture of membranes, PROM,
PPROM, prolonged PPROM, SROM, SPROM, ROM, intraamniotic infection, pulmonary hypoplasia,
oligohydramnios
INTRODUCTION
Eighty-five percent of neonatal morbidity and mortality is a result of prematurity.
Preterm premature rupture of the membranes (PPROM) is associated with 30-40 percent of preterm
deliveries and is the leading identifiable cause of preterm delivery. The 3 most common
risk factors for PPROM are smoking, previous preterm delivery, and vaginal bleeding at
any time during the index pregnancy.
The terminology pertaining to premature rupture of membranes (PROM) can be confusing, so
understanding the subtle distinctions can be valuable. PROM is rupture of the membranes
(ROM) prior to the onset of labor. PROM is used appropriately when referring to a patient
who is beyond 37 weeks of gestation, has presented with spontaneous rupture of the membranes
(SROM), and is not in labor. PPROM is ROM prior to the onset of labor in a patient who is
at less than 37 weeks of gestation. PROM is ROM prior to 37 weeks of gestation and may
imply that the patient is in labor. This has also been abbreviated as SPROM, ie, spontaneous
premature rupture of membranes. Otherwise, this patient is referred to as having PPROM.
Prolonged ROM is any ROM that persists for more than 24 hours. This article focuses on
the management of PROM (at term) and PPROM.
PROM AT TERM
PROM is ROM prior to the onset of labor at or beyond 37 weeks of gestation. Incidence
of PROM is approximately 10 percent of pregnancies. Patients with PROM may present with chief
complaints of leaking fluid, vaginal discharge, vaginal bleeding, and pelvic pressure,
but they are not in labor. (Labor is defined as regular, painful uterine contractions
resulting in progressive cervical effacement or dilation.)
The diagnosis of PROM can be made by looking for pooling of fluid in the vagina or leakage
of clear fluid from the cervix and by ferning or arborization of this vaginal fluid when
allowed to dry on a glass slide and viewed with a light microscope and/or contacted with
Nitrazine paper (which turns blue in contact with the vaginal fluid). Blood contamination
of the Nitrazine paper can invalidate results.
Avoid a digital cervical examination unless prompt or immediate delivery is expected.
If the diagnosis is still in question, the amniotic fluid index (AFI) can be helpful.
If doubt still exists, transabdominal instillation of 1 mL of indigo carmine dye in 9
mL of sterile saline into the amniotic cavity under ultrasound guidance and observations
of staining on a vaginal tampon or a sanitary pad should alleviate any question of ROM.
The natural history of PROM progresses in such a way that 90 percent of patients enter spontaneous
labor within 24 hours. The major question regarding management of these patients is
whether to allow them to enter labor spontaneously or to induce labor. In large part,
the management of these patients depends on their desires; however, the major maternal
risk at this gestational age is intrauterine infection. The risk of intrauterine infection
increases with the duration of ROM. Evidence supports the idea that induction of labor,
as opposed to expectant management, decreases the risk of chorioamnionitis without
increasing the cesarean delivery rate.
Hannah et al studied 5041 women with PROM who were randomly assigned to induction of labor
with intravenous oxytocin or vaginal prostaglandin E2 gel versus expectant management for
as many as 4 days with induction of labor for complications. The researchers concluded
that, in women with PROM, induction of labor with oxytocin or prostaglandin E2 gel and
expectant management resulted in similar rates of cesarean delivery and neonatal infection.
Induction with oxytocin, however, resulted in a lower risk of maternal infection
(endometritis) when compared with expectant management. Additionally, the women in the
study viewed induction of labor more favorably than expectant management.
A small study in the European literature concluded that women with PROM at term who have
an unfavorable cervical examination can be safely managed expectantly and that expectant
management resulted in fewer operative vaginal deliveries. This prospective randomized
trial enrolled a total of 154 patients (Alcalay et al, 1996). In addition, several
prospective studies have reported that with an unfavorable cervix, expectant management
decreased the cesarean delivery rate and length of labor without increasing infectious
morbidity.
If a patient desires expectant management after being presented with the evidence and a
recommendation by her caregiver, undertake this course in the hospital and not at home.
In Hannah's subanalysis of the International Term PROM Study, 650 women were expectantly
managed at home and 1017 were expectantly managed in the hospital. The conclusions of this
analysis were that, "expectant management at home, rather than in a hospital, might
increase the likelihood of some adverse outcomes (eg, cesarean section rate, numbers of
neonates admitted to the NICU for greater than 24 hours, neonatal sepsis)." An additional consideration
in hospital management is the choice of care to administer in the hospital. The safest
course is complete bedrest with continuous fetal heart rate monitoring. Alternative
management strategies include intermittent monitoring with some ambulation, which includes
bathroom privileges.
Regardless of which management scheme is undertaken, always consider a patient's desires
when designing a plan for management, and then carefully document the discussion points.
PPROM
PPROM is far more complicated than PROM at term. Questions about hospital versus home
management, steroid administration, antibiotic prophylaxis, tocolytic use, risks for
pulmonary hypoplasia, fetal surveillance, bed rest, and hydration may depend on gestational
age and multiple comorbidities. Important factors affecting neonatal outcome are gestational
age at delivery, estimated fetal weight, presence or absence of infection, and whether a
course of steroids has been completed. These concerns are addressed throughout the
remainder of this article.
Multiple options for management are available in the absence of fetal distress, non-reassuring
fetal heart rate tracings, overt intrauterine infection, or a maternal indication for
delivery.
MANAGEMENT OF PPROM
The gestational age and the presence or absence of an intraamniotic infection
(chorioamnionitis) determine the initial management of patients with PPROM. If a patient
has evidence of intraamniotic infection by clinical examination (eg, maternal temperature greater than
38°C, fetal tachycardia, fundal tenderness, foul or purulent vaginal discharge, maternal
tachycardia, elevated C-reactive protein level) or by amniocentesis (positive Gram stain
finding, glucose less than 20 mg/dL, positive amniotic fluid culture results for aerobic or anaerobic
organisms or Mycoplasma species), institution of broad-spectrum antibiotics and delivery
are necessary, regardless of gestational age.
Reduced fetal heart rate variability is not a sensitive sign in preterm infants. If a
patient is at more than 32 weeks of gestation and has documented fetal lung maturity, delivery
is recommended. Finally, if a patient has reached 32-35 weeks gestation and has documented
ROM, delivery in the absence of documented pulmonary maturity may be considered in
institutions with a NICU equipped to manage the complications of prematurity.
Each institution must have an idea of how well neonates at various gestation ages do at that
particular institution. No uniform agreement has been reached on the optimal gestational age
(regardless of local NICU statistics) at which delivery should be undertaken. The overall goal
is to manage the patient expectantly until she has reached a gestational age beyond which
neonatal morbidity and mortality is minimal and to achieve delivery before the mother and/or
her fetus become infected.
PPROM & ANTIBIOTICS, CORTICOSTEROIDS, FETAL SURVEILLANCE, AND TOCOLYTICS
If the decision to manage a patient expectantly has been made, the institution of broad-spectrum
antibiotics is advantageous. Multiple trials have examined the advantages and disadvantages of using
antibiotics and the choice of antibiotics. Use of antibiotics has been associated with prolongation
of pregnancy and reduction in infant and maternal morbidity.
The summary of the available literature supports the use of ampicillin (2 g IV q6h) and erythromycin
(250 mg IV q6h) for 48 hours, followed by amoxicillin (250 mg PO q8h) and erythromycin base (333 mg
PO q8h) for 5 days, for a total of 7 days of antibiotics. An alternative is ampicillin/sulbactam
(3 g IV q6h) for 48 hours, followed by amoxicillin/clavulanate (250 mg PO q8h) for 5 days, for a
total of 7 days of antibiotics. A broad-spectrum cephalosporin or clindamycin may be substituted
in patients who are allergic to penicillin. Prolonged antibiotics offer no advantages and may promote
the emergence of resistance (eg, ampicillin-resistant Escherichia coli).
Little controversy about who should receive steroids should exist. The Consensus Development Panel
of the National Institutes of Health recommends corticosteroid use for women with PPROM prior to
30-32 weeks of gestation in the absence of clinical chorioamnionitis. The dose is betamethasone
12 mg IM qd for 2 days. In the initial statement, an allowance was also made for dexamethasone, but
a considerable amount of evidence has developed since then that favors betamethasone for many reasons.
No evidence supports the use of subsequent courses of this therapy.
Perform antepartum fetal surveillance at least daily, which may consist of a non-stress test (NST)
and AFI. No evidence supports one form of testing over another or any specific frequency.
Tocolytics may be used to prolong gestation long enough to complete a course of corticosteroids
(betamethasone 12 mg IM qd for 2 d). Be absolutely certain that an intraamniotic infection is not
present before beginning tocolytics.
Pelvic rest is of utmost importance, as the risk of ascending infection increases not only with the
duration of ruptured membranes but also with manipulation of the cervix. Examine the cervix with
a sterile speculum and not digitally. Furthermore, there is no need for frequent cervical examinations
in a patient who is without complaints of regular uterine contractions, pelvic pressure, vaginal
bleeding, or other signs and/or symptoms of labor.
The single exception is in the patient who has advanced cervical dilation and/or a non-vertex
presentation. These patients are at increased risk for umbilical cord prolapse and may require more
frequent cervical examinations (sterile speculum) to assess whether further cervical dilation has
occurred. If the patient has advanced cervical dilation (ie, enough dilation to allow an umbilical
cord to prolapse) and/or a non-vertex presentation, continuous fetal heart rate monitoring may be
necessary. In many instances of cord prolapse, the only sign may be severe variable decelerations
or a prolonged deceleration in the fetal heart rate. This is difficult to diagnose with intermittent
fetal heart rate monitoring.
Again, any evidence of intraamniotic infection should prompt a move toward delivery. Practitioners
should have a low threshold for diagnosing infection in light of recent evidence documenting how much
more poorly neonates who are infected do compared to neonates who are not infected.
PPROM IN THE SECOND TRIMESTER
ROM prior to fetal viability poses unique problems. From 1984-1995, 11 maternal and fetal outcomes
in pregnancies with PPROM in the second trimester (13-26 weeks) were reported. The major maternal
risk is infection, namely chorioamnionitis. The major morbidity in the fetus with mid-trimester ROM
is lethal pulmonary hypoplasia from prolonged, severe, early oligohydramnios.
Chorioamnionitis occurs in 30-60 percent of patients with second-trimester PPROM. The risk of
infection increases with duration of ROM and an AFI less than 2.0 cm. Frequent examinations are
necessary to ensure maternal safety. Patients must be educated about the warning signs of intraamniotic
infection, and they must take their temperature 3 times a day at home. These patients do not require
hospitalization if no evidence of vaginal bleeding or infection exists. Patients may consider
admission for inpatient management at 24 weeks, the juncture currently considered the point of
viability at most institutions.
Pulmonary hypoplasia is the most serious fetal complication and can be lethal. The presence of
severe (AFI less than 2.0 cm), prolonged (greater than 14 days), and early (less than 25 weeks at
onset) oligohydramnios has been associated with a neonatal mortality rate greater than 90 percent
in one study. In other studies, the gestational age at the time of PPROM had the most significance
when predicting pulmonary hypoplasia. In the human fetus, ROM during the canalicular stage (13-25 weeks)
has the most dismal prognosis. The diagnosis of pulmonary hypoplasia is made at autopsy by weighing
the lungs. Several schemes exist for predicting pulmonary hypoplasia antenatally using lung lengths
and/or thoracic circumference ratios, but the functional capacity of the lung cannot be predicted,
only the amount of tissue present.
Mid-trimester (13-26 weeks) PPROM has a dismal prognosis. Survival varies with gestational age at
diagnosis (from 12 percent when diagnosed at 16-19 weeks to as much as 60 percent when diagnosed at
25-26 weeks). Until viability, maternal well-being should be of paramount concern.
SUMMARY
Manage PROM at term according to the patient's wishes, the cervical examination, and the presence
or absence of any comorbidities (eg, infection). Evidence to support induction of labor shortly
after diagnosis of PROM exists, and this is the protocol at the author's institution, with few exceptions.
PPROM is considerably more complicated and requires a thorough evaluation for gestational age, fetal
position, presence of infection, and fetal and maternal well-being. Decisions about management are
affected by each of these variables.
Second-trimester PPROM has a dismal prognosis. This condition requires an understanding of the
literature, thorough counseling, and documentation.
BIBLIOGRAPHY
- ACOG Practice Bulletin Number 1: Clinical management guidelines for Obstetrician-Gynecologists: Premature rupture of membranes. June, 1988.
- Alcalay M, Hourvitz A, Reichman B: Prelabour rupture of membranes at term: early induction of labour versus expectant management. Eur J Obstet Gynecol Reprod Biol 1996 Dec 27; 70(2): 129-33[Medline].
- Farooqi A, Holmgren PA, Engberg S: Survival and 2-year outcome with expectant management of second- trimester rupture of membranes. Obstet Gynecol 1998 Dec; 92(6): 895-901[Medline].
- Hannah ME, Hodnett ED, Willan A: Prelabor rupture of the membranes at term: expectant management at home or in hospital? The TermPROM Study Group. Obstet Gynecol 2000 Oct; 96(4): 533-8[Medline].
- Hannah ME, Ohlsson A, Farine D: Induction of labor compared with expectant management for prelabor rupture of the membranes at term. TERMPROM Study Group. N Engl J Med 1996 Apr 18; 334(16): 1005-10[Medline].
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