6 - Premature rupture of membranes (PROM)

1. See Also
1. Preterm Labor
2. Preterm Labor Management
2. Definitions
1. Premature Rupture of Membranes (PROM)
1. Rupture of membranes >1 prior to labor onset
2. Preterm Premature Rupture of Membranes (PPROM)
1. PROM that occurs prior to 37 weeks gestation
3. Epidemiology
1. Incidence
1. Premature Rupture of Membranes (PROM): 8%
2. Preterm Premature Rupture of Membranes (PPROM): 2%
4. Symptoms
1. Gushing of fluid from vagina
2. Fluid leakage increases with movement change
5. Signs
1. See evaluation below
6. Differential diagnosis
1. Urinary Incontinence
2. Vaginal Discharge
3. Water from recent bathing
7. Complications
1. Premature Birth (PPROM)
2. Chorioamnionitis
3. Cord compression
4. Respiratory distress syndrome
5. Abruptio Placentae
6. Malpresentation
8. Course prior to delivery
1. Term: Labor starts within 24 hours in 95% of cases
2. Weeks 28 to 34
1. Labor starts within 24 hours in 50% of cases
2. Labor starts within 1 week in 80% of cases
3. Weeks 24 to 26
1. Labor starts within 1 week in >50%
2. Labor delayed 4 weeks in 22%
4. References
1. Schucker (1996) Semin Perinatol 20:389
9. Risk Factors
1. History of PROM in prior pregnancy
2. Prior cervical cone biopsy
3. Amniocentesis or Cerclage
4. Uterine distention
1. Polyhydramnios
2. Multiple Gestation pregnancy
5. Tobacco abuse
6. Cervical or vaginal infections
1. Group B Streptococcus
2. Bacterial Vaginosis
3. Mycoplasma
4. Ureaplasma
5. Neisseria Gonorrhea
6. Chlamydia
7. Intercourse (unproven)
10. Evaluation
1. Methods to confirm rupture of membranes
1. Vaginal Pooling
2. Vaginal Fluid Ferning
3. Vaginal Fluid pH (Nitrazine)
2. Other bedside evaluation
1. Visualize cervix with speculum to estimate dilation
2. DNA probe for Chlamydia and Gonorrhea
3. Group B Streptococcus culture from vagina and rectum
4. Fetal monitoring for well-being
3. Advanced diagnostics to consider
1. Consider ultrasound
1. May help confirm diagnosis (oligohydramnios)
2. Determines Fetal Position and placental location
3. Estimates fetal weight
2. Amniocentesis
1. Evaluate Fetal Lung Maturity
2. Method to confirm ROM in uncertain cases
1. Uses Indigo carmine dye 1 ml in 9 ml sterile NS
2. Instilled into uterus via amniocentesis
3. Vaginal tampon turns blue within 30 min in ROM
11. Precautions: Avoid digital cervical exam in PPROM
1. Digital exam raises infection risk, other morbidities
1. Alexander (2000) Am J Obstet Gynecol 183:1003
2. Digital exam reduces time to labor by 9 days
1. Lewis (1992) Obstet Gynecol 80:630
3. Speculum visualization offers similar dilation estimate
1. Munson (1985) Am J Obstet Gynecol 153:562
12. Management: Term Premature Rupture of Membranes (PROM)
1. Indications
1. Fetus 36 weeks gestation or
2. Weight >2500 grams or
3. Fetal Lung Maturity adequate by amniocentesis
2. Protocol
1. Expectant management
2. Consider Oxytocin induction of labor
1. Spontaneous labor onset within 48 hours in 90%
2. Oxytocin decreases PROM infection rates
3. Oxytocin does not increase ceserean rates in PROM
3. Consider Cervical Ripening if unfavorable cervix
1. Decreases risk of Chorioamnionitis in PROM
2. Does not increase ceserean rate in PROM
4. Indications for GBS Prophylaxis
1. Prolonged ruptured membranes anticipated >18 hours
2. Fever >38 degrees Celsius
13. Management: Preterm Premature Rupture Membranes (PPROM)
1. Indications
1. Fetus <32-34>
2. Weight <2500>
3. Indequate Fetal Lung Maturity
2. Protocol: General
1. See Preterm Labor Management
2. Tocolysis
1. Delay labor unless overt infection, Fetal Distress
3. Maternal Corticosteroids for 2 days (single course)
1. Betamethasone 12 mg IM 2 doses 24 hours apart or
2. Dexamethasone 6 mg IM 4 doses 12 hours apart
4. Maternal antibiotic prophylaxis
1. See GBS Prophylaxis
2. Antibiotic protocol improves neonatal outcomes
1. Initial 48 hours start with IV agents
1. Ampicillin 2 grams IV q6 hours and
2. Erythromycin 250 mg IV q6 hours
2. After 48 hours, switch to oral agents for 5 days
1. Amoxicillin 250 mg PO q8 hours and
2. Erythromycin base 333 mg PO q8 hours
3. Reference
1. Mercer (1997) JAMA 278:989
5. Consider transfer to tertiary care center
6. Avoid digital cervical exam
7. Observation
1. Signs of Chorioamnionitis
2. Fetal well-being
3. Protocol: Gestational age specific
1. Gestational age 34 weeks or older
1. Consider transport to facility with NICU
2. Antibiotics (see regimen above)
3. Labor Induction
2. Gastational age 32-33 weeks
1. Transport to facility with NICU
2. Antibiotics (see regimen above)
3. Amniocentesis for Fetal Lung Maturity
1. Fetal lungs mature: Labor Induction
2. Fetal lungs not mature
1. Maternal Corticosteroids as above
2. Delay delivery 48 hours (preferably >34 weeks)
3. Gestational age 24-31 weeks
1. Transport to facility with NICU
2. Antibiotics (see regimen above)
3. Daily or continuous fetal monitoring
1. Higher risk of cord compression
4. Gestational age <24>
1. Consultation with neonatology
14. References
1. Morrison (2000) ALSO, p. 1-7
2. Ehrenberg (2001) Clin Perinatol 28(4):807
3. Lee (2001) Clin Perinatol 28(4):721
4. Medina (2006) Am Fam Physician 73(4):659

4 - preterm delivery

1. Definition of Preterm labor
1. Gestational age 20-37 weeks
2. Contractions with cervical change
2. Epidemiology
1. Incidence 7-8% of deliveries
3. Differential Diagnosis
1. Gastrointestinal
1. Appendicitis
2. Constipation
2. Uterus
1. Uterine Fibroids
2. Placental Abruption
3. Urinary
1. Acute Cystitis
2. Pyelonephritis
3. Nephrolithiasis
4. Musculoskeletal
1. Abdominal wall strain
4. Risk Factors predisposing to Preterm Labor
1. No associated risk factor in 50% of preterm labor
2. Tobacco abuse over 1/2 pack per day Cigarettes
3. Prior cervical cone biopsy
4. Pyelonephritis
5. Advanced cervical dilatation
6. Increased Uterine Size
1. Twin Gestation
2. Polyhydramnios
7. Low pre-pregnant weight (Body Mass Index <19.8)
8. Low socioeconomic status or poor nourishment
9. Prior preterm delivery
10. History spontaneous second trimester abortion
11. African American race
12. Uterine anomaly
1. Unicornuate uterus or bicornuate uterus
2. Uterine Fibroids
3. Diethylstilbestrol (DES) exposure in utero
13. Genitourinary Infection (40% of preterm births)
1. Urinary Tract Infection
1. Pyelonephritis
2. Asymptomatic Bacteriuria in Pregnancy
2. Vaginal infections
1. Group B Streptococcus (PPROM)
2. Bacterial Vaginosis
1. N Engl J Med (1995) 333:1732
3. Sexually Transmitted Disease
1. Neisseria gonorrhoeae
2. Chlamydia trachomatis
3. Trichomonas vaginalis
4. Syphilis
4. Infections with possible risk
1. Ureaplasma urealyticum
2. Mycoplasma hominis
5. Symptoms
1. Keep a high index of suspicion
1. Contraction frequency does not predict risk
2. Symptoms do not predict risk
2. Pelvic pressure
3. Vaginal pain
4. Menstrual-like cramps
5. Backache
6. Vaginal Discharge or fluid leakage (see PPROM)
7. Vaginal Bleeding
6. Signs
1. Examine Cervix as soon as possible
1. Avoid cervical exam until labor if PPROM confirmed
2. Examine Uterus
1. Assess for Abruptio Placentae
2. Check for firm, tender uterus with minimal relaxation
7. Evaluation: Four key concerns
1. Determine if patient is in labor
1. Evaluate abdominal or Pelvic Pain
2. Distinguish preterm labor from preterm contractions
2. Determine if membranes are ruptured
1. See Labs below
3. Establish clear gestational age
1. Review Last Menstrual Period
2. Review Estimated Due Date
3. Review prior ultrasound dating
4. Does fundal height correlate with gestational age
4. Evaluate maternal and fetal health
1. Consider underlying injury or infection
1. Recent trauma
2. Vaginal infection
3. Urinary Tract Infection in pregnancy
2. Consider comorbidity
1. Gestational Diabetes
2. Pregnancy Induced Hypertension
3. Intrauterine Growth restriction
4. Oligohydramnios or Polyhydramnios
3. Evaluate fetal activity and fetal health
1. External fetal monitoring
8. Labs
1. Evaluate for Rupture of Membranes
1. Nitrazine Testing
2. Ferning
2. Microscopy to evaluate Vaginitis
1. Saline wet preparation
2. KOH Preparation
3. Culture
1. Gonorrhea Culture
2. Chlamydia culture
3. Group B Streptococcus Culture (Todd Hewitt media)
1. Periurethral or outer-third of vaginal swab
2. Rectal swab
4. Urine Culture
5. Consider non-genitourinary sources of infection
4. Other Testing
1. Fetal Fibronectin
1. Reassuring if negative
2. Poor Positive Predictive Value
2. Urine testing
1. Urinalysis and Urine Culture
2. Urine drug Screening
5. Fetal Lung Maturity Assessment
1. Indicated for 34 week gestation or greater
9. Radiology: Obstetric Ultrasound
1. Fetal evaluation
1. Biophysical Profile
2. Amniotic fluid index
2. Placental location
3. Fetal Presentation
4. Estimated Fetal Weight (EFW)
5. Ultrasound Exam of Cervical Length
10. Efficacy of evaluation criteria
1. Evaluation criteria do not predict preterm delivery
1. Fetal Fibronectin
2. Uterine contraction frequency
3. Cervical Length assessment
2. These criteria however have Negative Predictive Value
1. No Cervical Length change and negative fibronectin
2. Suggests less than10% chance of preterm delivery
3. References
1. Iams (2002) N Engl J Med 346:250
11. Management
1. See Preterm Labor Management
12. References
1. Iams in Gabbe (2002) Obstetrics p.755