Premature Rupture of Membranes

FAHAD ZAKWAN

Premature rupture of membranes (PROM)Spontaneous rupture of membranes anytime beyond

28wks of pregnancy but before the onset of labour.

Preterm premature rupture of membranes (PPROM) rupture of fetal membranes prior to labor in pregnancies

btw 28 - 37 weeks.

DEFINITION

When rupture of membranes occurs beyond 37 wks. but before the onset of labour it is called term PROM.

Rupture of membranes for more than 24hrs before delivery is called prolonged rupture of membranes.

•Latency Period: time interval between ROM and onset of labor

•Expectant management: management of patients with the goal of prolonging gestation (“watchful waiting” until delivery indication arises)

RISK FACTORS• Chorioamnionitis

• Vaginal infections

• Cervical abnormalities

• Vascular pathology (incl. abruptio)

• Smoking

• 1st, 2nd, 3rd, or multiple trimester bleeding

• Previous preterm delivery (PPROM)

• AA ethnicity

• Acquired or congenital connective tissue disorder

• Nutritional deficiencies (Vit. C, copper, zinc)

What causes premature rupture of membranes?• Rupture of the membranes near

the end of pregnancy (term) may be caused by a natural weakening of the membranes or from the force of contractions. Before term, PPROM is often due to an infection in the uterus.

• Other factors that may be linked to PROM include the following:

1. Low socioeconomic conditions (as women in lower socioeconomic conditions are less likely to receive proper prenatal care)

2. Sexually transmitted infections such as chlamydia and gonorrhea

3. Previous preterm birth

4. Vaginal bleeding

5. Cigarette smoking during pregnancy

6. Unknown causes

SYMPTOMS AND SIGNS

• Vaginal discharge

•Gush of fluid• Leaking of fluid

• Oligo/ Anhydramnios

•Cramping

•Contractions

•Back pain

History & Physical Exam

History

1. “Gush” of fluid 2. Steady leakage of small

amounts of fluid

Physical examination•Sterile vaginal speculum exam•Minimize digital examination of cervix, regardless of

gestational age, to avoid risk of ascending infection/ amnionitis

1. Assess cervical dilation and length2. Obtain cervical cultures (Gonorrhea, Chlamydia)3. Obtain amniotic fluid samples

Findings

•Pooling of amniotic fluid in posterior vaginal fornix

•Fluid per cervical os

DIAGNOSIS• Valsava maneuver

• Sterile Speculum exam (Pooling)

• Nitrazine testing

• Fetal Fibronectin

• Ultrasonography

• SSE-Free flow of fluid from cervical os

• Microscopic Fern testing

• AmniSure

• Transabdominal Indigo dye injection

Nitrazine paper testing

• Vaginal pH (3.5-4.5)

• Turns blue in presence of alkaline Amniotic fluid

• 93.3% sensitivity

• False positive (1-17%) for urine, blood, semen, BV, Trichomoniasis

Fern test• Fern test refers to visualization of

a characteristic 'fern-like' patternon a slide (pre-cleaned, saline free slides are required), viewed under low power on a microscope

• A small amount of cervical mucus is allowed to air-dry on a clean, saline-free glass slide

Procedure:1. When the slide has completely

air dried (at least 5 to 7 minutes), place it on the stage of the light microscope provided for the procedure.

2. Examine the slide under low power (10X).

3. Look for fern-like crystals. If positive for amniotic fluid, this crystal formation will be present in most microscopic fields.

Fetal Fibronectin• fFN present in cervical

secretions <22 wks, >34 wks

• Used for assessment of potential PTB

• Positive result (>50 ng/dl) may be indicative of PROM and represents disruption of decidua-chorionic interface

In PPROM, Sensitivity-98.2%, Specificity-26.8%.

Ultrasonography• 50-70% of women with

PPROM have low AFV on US

• Mild reduction requires further investigation

• Rule out other causes (Renal agenesis, utero-placental insufficiency, obstructive uropathy)

• Measure for pockets of fluid and quantitate AFV into AFI

Ultrasound showing 7 cm pocket of fluid

Transabdominal Injection of Dye (Amniocentesis)

• Under ultrasound guidance a high-gauge long needle is inserted through the abdomen and membranes into the uterine cavity and amniotic fluid can be collected for testing of chorioamnionitis, in addition to fetal lung maturation studies.

• After fluid sample collection, 10 cc of mixed Indigo Carmine dye is then injected into the amniotic fluid. The dye is bright blue and if blue is noted on the tampon after 30-60 mins, the diagnosis of ruptured membranes is made.

PPROM

Sudden gush of clear vaginal fluid with oligohydramnios

SPECULUM EXAM

Pooling, Nitrazine, ferning

Diagnosis of PROM

Pooling +

Nitrazine +

Ferning +

MANAGEMENTMANAGEMENT DEPENDS ON THE FOLLOWING FACTORS

• Gestational age

• Availability of NICU

• Fetal presentation

• FHR pattern

• Active distress (maternal/fetal)

• Is she in labor?

• Cervical assessment

Initial Assessment

Assess for Maternal-Fetal distress

Assess for Proper dating/GA

Assess for infection

Exclude occult cord prolapse

• Maternal-Fetal Distress evaluated by Maternal VS, labs, general condition, Fetal distress assessed by FHR pattern, US, Biophysical profile (US examining fetal tone, FBM, AFI, GBM for a score of 2 each if criteria met for a total of 8/8)

• First priority is to rule out maternal-fetal distress and imminent delivery.

• Ensure through prenatal records that early US correlate with LMP or EDC is most accurate.

• Rule out infection through absence of clinical signs and symptoms of chorion in addition to assessment of lab values and amniotic fluid samples obtained through Amniocentesis.

• Evaluate maternal serum lab values for leukocytosis, left shift, and elevated C-Reactive Protein. Evaluate Amniotic fluid samples for gram stain, leukocyte esterase, glucose, and WBC count.

• Exclude occult cord prolapse through assessment of fetal distress.

•Variable FHR decelerations can be seen in the FHR pattern in patients with low or no amniotic fluid. In addition, late decelerations may be seen also in patients with co-existing abruption.

•Assess for signs and symptoms of chorioamnionitis, abruption, labor, fetal distress. Assess maternal VS for tachycardia and fever.

Assessing for signs and symptoms of chorioamnionitis

Secondary Assessment

•Fetal position•Cervical assessment •Determine lung maturity, if indicated•Quantify AFV*

• Determine fetal position per Leopold’s and confirm with US for all patients, especially since likelihood of breech presentations is higher at earlier gestations remote from term.

• Assess for labor by visual examination of the cervix with SSE unless the patient is presenting with regular, painful contractions and appears to be in active labor. Time contractions, assess for pelvic pressure, PALPATE for contractions and strength. Ask mom for length of last labor, if applicable. If patient is in active labor and delivery is inevitable, consider discontinuation of all tocolytics.

• Again, ONLY do digital cervical exams on patients who are in active labor or patients who need to be delivered for clinical reasons and consistency of cervix needs to be assessed.

• Fetal lung maturity generally assessed at 32 weeks and beyond if necessary. Fetal lungs likely to be immature at gestations less than 32 weeks. Evaluation of FLM should only be evaluated in the absence of absolute delivery indications. Consider risk-benefit ratio of neonatal mortality and morbidity when deciding to induce labor or perform Cesarean section.

• Quantification of Amniotic fluid volume has increasingly been used to evaluate risk. Patients with vertical pockets of fluid <2 cm have a shorter latency period, and a higher incidence of chorioamnionitis, neonatal sepsis, and endometritis whereas similar patients with a vertical pocket of >2cm have a lesser incidence of these.

Delivery Indication

1. Maternal-Fetal Distress

2. Infection

3. Abruption

4. Cord Prolapse

Expectant Management• Typical for GA 32 weeks or less

• Bed rest

• Steroids for lung maturity

• Tocolytic if indicated for lung maturity

• Antibiotics

• Fetal Surveillance

• Majority Inpatient Observation

• Assess for Chorioamnionitis

• Some expectantly manage patients until 34 weeks gestation in the absence of delivery indication.

• Betamethasone-may be given 12 mg IM q 12 or 24 hours x 2 total doses. Need at least 48 hours to initiate benefit. May also use Dexamethasone. Steriods may increase WBC’s and therefore baseline CRP should be obtained and consistently monitored.

• In the absence of delivery indication, may consider tocolysis x 48 hours to assist with benefit of sterods. Tocolysis can be achieved with magnesium sulfate, terbutaline, and nifedipine.

• Prophylactic antibiotics should be obtained after collection of cultures. These cultures may include Group B Strep culture, GC, Chlamydia, Amniotic fluid sample.

• Broad antimicrobial coverage is recommended.

• Antibiotic administration reduced the incidence of chorioamnionitis, neonatal infection, and the use of neonatal surfactant.

• Antibiotic administration for most centers include Ampicillin IV (if no allergy) for 48 hours then a switch to oral amoxillin for an additional five days.

• Additional of a macrolide considered necessary for broad coverage. Commonly used is a single dose of 1 gram of Azithromycin, or Erythromycin IV with a switch to oral EES after 48 hours for an additional 5 days.

• Infection can be both a cause and a consequence of Preterm Rupture of Membranes.

• Most patients require close inpatient observation. Those who might qualify for outpatient management include the extreme previable gestation patients and those who have appeared to have resealed (which is approximately about 5% of PROM patients).

• Assessment for chorioamnionitis includes amniocentesis (diagnostic), in addition to clinical signs and symptoms and CRP, WBC counts, and other maternal serum infection indices.

Expectant management Deliver at 34 wks

Unless documented fetal lung maturity

GBS prophylaxis

Antibiotics

Single course corticosteroids

TocolyticsNo consensus

Management: PPROM(24 – 31 wk. gestation)

Expectant managementDeliver at 34 wks

Unless documented fetal lung maturity

GBS prophylaxis

Antibiotics

CorticosteroidsNo consensus, some experts recommend

Management: PPROM(32 – 33 wk. gestation)

Proceed to deliveryInduction of labor

GBS prophylaxis

Management: PROM(> 34 wk. gestation)

Antibiotics Prolong latency period

Prophylaxis of GBS in neonate

Prevention of maternal chorioamnionitis and neonatal sepsis

Corticosteroids Enhance fetal lung maturity

Decrease risk of RDS, IVH, and necrotizing enterocolitis

Tocolytics Delay delivery to allow administration of corticosteroids

Controversial, randomized trials have shown no pregnancy prolongation

Management: Rationale

AntibioticsAmpicillin 2 g IV 6 hrly for 2 days

Amoxicillin 500 mg po TDS x 5 days

Azithromycin 1 g po x 1

Erythromycin 250mg TDS for 5 days

CorticosteroidsBetamethasone 12 mg IM OD for 2 days

Dexamethasone 6 mg IM BD for 2 days

TocolyticsNifedipine 10 mg po after every 20min 3 times, then 6 hrly for 2 days

Management: Drug Regimen

Typically performed after 32 wks

Tests for fetal lung maturity (FLM) Lecethin/Sphingomyelin ratio (not commonly used, more

for historic interest) L/S ratio > 2 indicates pulmonary maturity

Phosphatidylglycerol > 0.5 associated with minimal respiratory distress

Flouresecence polarization (FLM-TDx II) > 55 mg/g of albumin

Lamellar body count 30,000-40,000

If negative, proceed with expectant management until 34 wks

Management: Amniocentesis

Risk-Benefit Expectant Management

• Abruption

• Chorioamnionitis

• Cord Prolapse

• Pulmonary Hypoplasia (<19 weeks PPROM

• Skeletal Deformities

• Endometritis (1/3)

• Mature lung profile

• Advancing GA (reducing risks associated with PTB)

Risks Benefits

Fetal complications of prolonged PPROM•Pulmonary hypoplasia •Skeletal malformations• IUGR• IUFD

Maternal complications of prolonged PPROM•Chorioamnionitis•Dry labour•Cord prolapse if malpresentation present.

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