Premature Rupture of Membranes

Assoc. Prof. Gazi YILDIRIM

List the history, physical findings, and diagnostic methods to confirm the rupture of the membranes

Identify the risk factors for premature rupture of membranes

Describe the risks and benefits of expectant management versus immediate delivery, based on gestational age

Describe the methods to monitor maternal and fetal status during expectant management

Objectives

Premature rupture of membranes (PROM) Rupture of the chorioamnionic membrane (amniorrhexis)

prior to the onset of labor at any stage of gestation

Preterm premature rupture of membranes (PPROM) PROM prior to 37-wk. gestation

Definition

PROM – 12% of all pregnancies PROM – 8% term pregnancies PPROM – 30% of preterm deliveries

Incidence

• Chorioamnionitis• Vaginal infections• Cervical abnormalities• Vascular pathology (incl. abruptio)• Smoking• 1st, 2nd, 3rd, or multiple trimester bleeding• Previous preterm delivery (PPROM)• Ethnicity• Acquired or congenital connective tissue disorder• Nutritional deficiencies (Vit.C, copper, zinc)

Risk factors

PROM/PPROM: Risk Factors

Risk Factors: Prior PROM or PPROM Prior preterm delivery Multiple gestation Polyhydramnios Incompetent cervix Vaginal/Cervical Infection

Gonorrhea, Chlamydia, GBS, S. Aureus Antepartum bleeding (threatened abortion) Smoking Poor nutrition

Vaginal discharge Gush of fluid Leaking of fluid Oligo/Anhydramnios Cramping Contractions Back pain

Symptoms

• Sterile Speculum Exam (Pooling)• SSE-Free flow of fluid from cervical os• Nitrizine testing• Microscopic Fern testing• Fetal Fibronectin• AmniSure • Ultrasonography• Transabdominal Indigo dye injection

Diagnosis

Diagnosis

• Latency period• Infection

History “Gush” of fluid Steady leakage of small amounts of fluid

Physical Sterile vaginal speculum exam

Minimize digital examination of cervix, regardless of gestational age, to avoid risk of ascending infection/amnionitis

Assess cervical dilation and length Obtain cervical cultures (Gonorrhea, Chlamydia) Obtain amniotic fluid samples (for fetal fibronectin ect.)

Findings Pooling of amniotic fluid in posterior vaginal fornix Fluid per cervical os

PROM/PPROM: History & Physical Exam

Test Nitrazine test

Fluid from vaginal exam placed on strip of nitrazine paper

Paper turns blue in presence of alkaline (pH > 7.1) amniotic fluid

Fern test Fluid from vaginal exam placed

on slide and allowed to dry Amniotic fluid narrow fern vs.

cervical mucus broad fern

PROM/PPROM: Diagnosis

False positive Nitrazine test Alkaline urine Semen (recent coitus) Cervical mucus Blood contamination Vaginitis (e.g. Trichomonas)

False-Negative Nitrazine test Remote PROM with no residual fluid Minimal amniotic leakage

PROM/PPROM: Diagnosis

PROM/PPROM: Diagnosis

AmniSure Detects trace amounts of placental alpha

microglobulin-1 protein in vaginal fluid. Newer test Point of Care test Cost-up to $50 each Sensitivity-98.7-98.9% Specificity-87.5-100%

Test Ultrasound

Assess amniotic fluid level and compatibility with PROM

Indigo-carmine Amnioinfusion Ultrasound guided indigo carmine dye amnioinfusion (“Blue tap”) Observe for passage of blue fluid from vagina

PROM/PPROM: Diagnosis

• Gestational age• Availability of NICU• Fetal presentation• FHR pattern • Active distress (maternal/fetal)• Labor? • Cervical assessment

PROM/PPROM: Management

Patient counseling Expectant management vs. induction of labor GBS prophylaxis NOT recommended Antibiotics

Incomplete data Corticosteriods NOT recommended

Management: PPROM(< 24 wk gestation – “previable”)

Patient counseling

Fetal complications of prolonged PPROM Pulmonary hypoplasia Skeletal malformations Fetal growth restriction IUFD

Maternal complications of prolonged PPROM Chorioamnionitis

Management: PPROM(< 24 wk gestation – “previable”)

Gestational Age(In Completed

Weeks)

Death BeforeNICU Discharge

Outcomes at 18 to 22 Months Corrected Age*

DeathDeath/ Profound

NeurodevelopmentalImpairment

Death/Moderate to Severe Neuro-developmental Impairment

22 Weeks 95% 95% 98% 99%23 Weeks 74% 74% 84% 91%24 Weeks 44% 44% 57% 72%25 Weeks 24% 25% 38% 54%

Expectant management Deliver at 34 wks Unless documented fetal lung maturity

GBS prophylaxis Antibiotics Single course corticosteroids Tocolytics

No consensus

Management: PPROM(24 – 31 wk gestation)

Expectant management Deliver at 34 wks Unless documented fetal lung maturity

GBS prophylaxis Antibiotics Corticosteroids

No consensus, some experts recommend

Management: PPROM(32 – 33 wk gestation)

Proceed to delivery Induction 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

Antibiotics Ampicillin 2 g IV Q6 x 48 hrs Amoxicillin 500 mg po TID x 5 days Azithromycin 1 g po x 1

Corticosteroids Betamethasone 12 mg IM q24 x 2 Dexamethasone 6 mg IM q12 x 4

Tocolytics Nifedipine 10 mg po q20min x 3, then q6 x 48 hrs

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

Maternal: Monitor for signs of infection Temperature Maternal heart rate Fetal heart rate Uterine tenderness Contractions

Fetal: Monitor for fetal well-being Kick counts Nonstress tests (NST’s) Biophysical profile (BPP)

Management: Surveillance

Immediate Delivery Intrauterine infection Abruptio placenta Repetitive fetal heart rate decelerations Cord prolapse

Management: Surveillance

Expectant Management Risks:

Maternal Increase in chorioamnionitis Increase in Cesarean delivery Spontaneous labor in ~ 90% within 48 hr ROM Increased risk of placental abruption

Fetal Increase in RDS Increase in intraventricular hemorrhage Increase in neonatal sepsis and subsequent cerebral palsy Increase in perinatal mortality Increase in cord prolapse

Expectant Management vs. Preterm Delivery