Premature Rupture of Membranes 01/01/2020

Term PROM

Term premature rupture of membranes (PROM) is defined as rupture of membranes before the onset of labor.  The most significant maternal risk of term PROM is intrauterine infection which increases with the duration of membrane rupture. Fetal risks include umbilical cord compression and ascending infection.

Preterm PROM

Preterm birth is defined as delivery before 37 weeks gestation.  Prematurity is the leading cause of perinatal mortality in the US and is the major reason why we lag behind other developed nations in infant mortality rates. Approximately 70% of neonatal deaths, 36% of infant deaths, and 25-50% of cases of long-term neurologic impairment in children can be attributed to preterm birth.(ACOG, 2016a) The estimated cost of preterm births exceeds $26.2 billion annually with an average cost of care for a preterm birth ten times greater than that of a full term birth, $32,325 to $3,325 respectively. (CDC, 2008) In 2015, preterm birth occurred in 9.6% of approximately 4 million births in the US and 11.7% of 59,632 births in the state of Alabama.(Hamilton, Martin, & Osterman, 2016)  The preterm birth rate in Alabama has increased slightly over the past year (11.66 % in 2014 to 11.73% in 2015) and Alabama has the third highest preterm birth rate in the nation. (Hamilton et al., 2016)

Preterm premature rupture of membranes (pPROM) is defined as rupture of membranes before 37 weeks GA; pPROM is a complication in approximately 1/3 of all preterm births. (Mercer, 2010)Birth within 1 week is the most likely outcome for any patient with pPROM in the absence of adjunctive treatments. The earlier in gestation pPROM occurs, the longer the latency period (time between PROM and delivery).  Outcomes of survivors of preterm PROM depend on GA, presence of infection, length of latency, and other maternal and fetal complications.  Factors contributing to preterm PROM include:
• Intraamniotic infection
• Low socioeconomic status
• Smoking
• Low BMI <19.8
• Prior history of PROM
• Cervical insufficiency
• History of subchorionic bleeding/hematoma

Diagnosis

PROM is diagnosed by the occurrence of any 2 of the following:

• Pooling of fluid in the vaginal vault
• Positive Nitrazine test
• Ferning of vaginal fluid

Or any 1 of the following:

• Indigo carmine pooling in the vagina after amnioinfusiono
• Visible leakage of amniotic fluid from the cervix.
• Biochemical test for rupture of membranes accompanied by a history consistent with SROM; several commercially available biochemical tests are on the market.
  • These biochemical tests have a specificity that ranges from 78-98% in studies. Therefore, results should be interpreted in light of the clinical history, presentation, and findings. Especially in preterm patients, ancillary information (e.g. ultrasound diagnosis of oligohydramnios) should support the diagnosis of ruptured membranes prior to enacting a management plan.
  • The additional cost of these biochemical tests should be considered. In the setting of a clear clinical diagnosis of PROM such tests likely add little additional useful knowledge.
  • Clinicians who utilize these tests should familiarize themselves with the sensitivity and specificity of the particular test utilized at their facility.

Management

Management depends on the GA at the time of confirmation of the diagnosis of ruptured membranes. At all gestational ages, expectant management is associated with a risk of ascending infection and umbilical cord compression, therefore the risks of expectant management must be balanced against the risks of immediate delivery. Approximately 50% of women who present with PROM will deliver in the first 7 days, many of them in the first 48 hours; however antibiotic treatment has been shown to significantly prolong latency in the setting of pPROM.

Recommendations

Delivery Management

• PROM at term (≥ 37 weeks) should be delivered to reduce the risk of chorioamnionitis and fetal infection.
• PROM at late preterm 34-36 weeks of gestation If the patient has not previously received antenatal corticosteroids, in the absence of chorioamnionitis and diabetes, a course of ANCS should be administered. See the APEC Antenatal Corticosteroid Use in the Late Preterm guideline; Delivery induction should be delayed for 48 hours to allow for steroid effect; If fetal status concerning, deliver regardless of steroid duration. (Gyamfi-Bannerman et al., 2016) See the APEC Antenatal Corticosteroids Use in the Late Preterm guideline.
• Delivery at 32-33 weeks with PROM may be considered if fetal pulmonary maturity has been documented otherwise plan delivery at 34 to 35 weeks gestation.
• PROM prior to 32 weeks should be managed expectantly until 34 weeks in the absence of maternal or fetal contraindications, overt uterine infections, labor, or fetal compromise. At 34 wk 0 d, the risk of continued expectant management begins to exceed the risk of prematurity and delivery and therefore delivery is generally recommended.
• Previable PROM < 23 weeks
  Patients who develop PROM less than 23 weeks are at markedly increased risk of neonatal morbidity and mortality from extreme prematurity and, especially with PROM prior to 20 weeks, lethal fetal/neonatal pulmonary hypoplasia, as well as maternal morbidity due to chorioamnionitis and sepsis. These patients should be referred to a tertiary center for counseling and management. If there is no evidence of labor, vaginal bleeding, or infection at the time of the initial presentation, the patient may be sent home with antibiotics to prolong latency and instructions for careful temperature surveillance and follow-up while awaiting outpatient evaluation at the tertiary center. Hospitalization in a tertiary care center should be considered at 23-24 weeks gestation.

Non-Delivery Management

• Patients with PROM <34 weeks, should be transported to a facility with a Level III nursery because of the potential for rapid labor progress and/or the need for expeditious delivery.

• All women with PROM and a viable fetus should receive GBS prophylaxis at the time of presentation and at the time of labor unless recent cultures (within 5 weeks) are negative for GBS. See APEC Group B Streptococci guideline. Some clinicians chose to obtain a GBS culture at the time of presentation with PROM. If this is done, these results, once available, should guide further decisions regarding GBS prophylaxis.

• Women with preterm PROM before 32 weeks who are thought to be at risk of imminent delivery should be considered candidates for fetal neuroprotective treatment with IV magnesium sulfate.(ACOG, 2013) See APEC Guideline: MgSO4 for Fetal Neuroprotection.

• Women with PROM between 23-36 weeks gestation should receive a single course of antenatal corticosteroids.

Latency Antibiotic Regimens

• Multiple studies have documented the ability of antibiotic therapy to prolong pregnancy and reduce infection in the setting of expectant management of PROM remote from term.

• Antibiotics maybe considered as early as 20 weeks of gestation to prolong latency.
• All patients with PROM should receive latency antibiotics regardless of GBS antibiotics.

• The most well studied regimen was that used in the NICHD Maternal-Fetal Medicine Units Network trial: A 48-hour course of intravenous ampicillin (2 g IV q 6) and erythromycin (250 mg IV q 6) followed by 5 days of amoxicillin (250 mg po q 8) and erythromycin (333 mg po q 8). ACOG currently endorces a combination of erythromycin and ampicillin or amoxicillin for 7 days, (ACOG, 2013) however, because of the side effects associated with this regimen and other studies suggesting benefit from slightly longer latency regimens, a number of alternative regimens have been developed. The key elements are: 1) a broad spectrum beta-lactam type antibiotic with gram negative coverage and 2) a macrolide antibiotic with coverage for atypical organisms.

• At UAB and USA, the standard regimen for PROM is: Ampicillin 2 g IV q 6 while in Labor and Delivery followed by Amoxicillin 500mg po TID x 10 days. In addition, patients receive Azithromycin 1 gram po on the day of admission and again on day 5.

• For patients who are PCN allergic, oral cephalexin 500 mg TID can be considered; in those without a history of anaphylaxis, Azithromycin should still be given ; prolonged oral clindamycin is NOT recommended due to GI side effects.

• Latency antibiotics should be continued until the onset of labor or until 10 days of therapy have been completed. Regardless of when labor ensues, GBS prophylaxis should be provided during labor unless a recent culture documented negative results.

Assessment

• Assess GA, fetal presentation, and well-being in all patients with PROM. Patients with intrauterine infection, abruptio placentae, or fetal compromise should be expeditiously delivered.

• Digital cervical examinations increase the risk of infection and should be avoided unless the patient is in active labor or delivery is imminently planned.  Sterile speculum examination provides an opportunity to inspect for cervicitis and umbilical cord prolapse, assess cervical dilatation and effacement, and obtain cultures as appropriate.

Transport to tertiary facility

In order to maximize perinatal outcomes, delivery of preterm infants should occur at facilities capable of providing the appropriate level of neonatal resuscitative and supportive care commensurate with the gestational age. The American Academy of Pediatrics has recently redefined levels of neonatal care providing recommendations to ensure each newborn infant if delivered and cared for in a facility most appropriate for his or her needs, see APEC Levels of Neonatal Care guideline. The importance of delivery location is underscored by the improved survival of these neonates when delivered at tertiary care centers. (Cunningham et al., 2010)

Quality Indicators/Benchmarks

• Antenatal corticosteroids <34 weeks GA
• Antibiotics for latency
• Magnesium sulfate for fetal neuroprotection <32 weeks GA
• Delivery at appropriate facility

References

ACOG. (2016a). Management of Preterm Labor Practice Bulletin 159. The American College of Obstetricians and Gynecologists.
ACOG. (2016b). Premature Rupture of Membranes Practice Bulletin # 160. The American College of Obstetricians and Gynecologists.
CDC. (2008). Final Natality Data. Hyattsville, MD.
Cunningham, F. G., Leveno, K. J., Bloom, S. L., Hauth, J. C., Rouse, D. J., & Spong, C. Y. (2010). Williams Obstetrics (23rd ed.). New York, USA: McGraw-Hill.
Gyamfi-Bannerman, C., Thom, E., Blackwell, S., Tita, A., Reddy, U., Saade, G., & al., e. (2016). Antenatal betamethasone for women at risk for late preterm delivery. N Engl J Med.
Hamilton, B., Martin, J., & Osterman, M. (2016). Births: Preliminary data for 2015. Hyattsville, MD: National Center for Health Statistics.
Mercer, B. (2010). Premature Rupture of the Membranes. In J. T. Queenan, J. C. Hobbins, & C. Y. Spong (Eds.), Protocols for High-Risk Pregnancies (5th ed.). West Sussex, UK: Wiley-Blackwell.
Pediatrics, A. A. o. (2012). Levels of Neonatal Care. Pediatrics, 130, 587-597.