Premature Rupture of Membranes

1. Premature Rupture of Membranes UNC School of Medicine Obstetrics and Gynecology Clerkship Case Based Seminar Series

2. Objectives for PROM • 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

3. Definition • 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

4. Incidence • PROM – 12% of all pregnancies • PROM – 8% term pregnancies • PPROM – 30% of preterm deliveries

5. PROM/PPROM: History & Physical Exam • 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 • Findings • Pooling of amniotic fluid in posterior vaginal fornix • Fluid per cervical os

6. PROM/PPROM: Diagnosis • 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

7. 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

8. PROM/PPROM: Diagnosis • 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

9. 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

10. Management: PPROM(< 24 wk gestation – “previable”) • Patient counseling • Expectant management vs. induction of labor • GBS prophylaxis NOT recommended • Antibiotics • Incomplete data • Corticosteriods NOT recommended

11. 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 http://www.nichd.nih.gov/about/org/cdbpm/pp/prog_epbo/dataShow.cfm

12. Management: PPROM(24 – 31 wk gestation) • Expectant management • Deliver at 34 wks • Unless documented fetal lung maturity • GBS prophylaxis • Antibiotics • Single course corticosteroids • Tocolytics • No consensus

13. Management: PPROM(32 – 33 wk gestation) • Expectant management • Deliver at 34 wks • Unless documented fetal lung maturity • GBS prophylaxis • Antibiotics • Corticosteroids • No consensus, some experts recommend

14. Management: PROM(> 34 wk gestation) • Proceed to delivery • Induction of labor • GBS prophylaxis

15. Management: Rationale • 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

16. Management: Drug Regimen • 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

17. Management: Amniocentesis • Typically performed after 32 wks • Tests for fetal lung maturity (FLM) • Lecethin/Sphingomyelinratio (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 Courtesy of Thomas Shipp, MD.

18. Management: Surveillance • 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)

19. Management: Surveillance • Immediate Delivery • Intrauterine infection • Abruptio placenta • Repetitive fetal heart rate decelerations • Cord prolapse

20. Expectant Management vs. Preterm Delivery • 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

21. Expectant Management vs. Preterm Delivery • Preterm Delivery Risks: use NICHD calculator • http://www.nichd.nih.gov/about/org/cdbpm/pp/prog_epbo/epbo_case.cfm

22. Bottom Line Concepts • Preterm premature rupture of membranes refers to rupture of fetal membranes prior to labor in pregnancies < 37 weeks. • A history of PPROM or PROM, genital tract infection, antepartum bleeding, and smoking are risk factors for PPROM and PROM. • A clinical history suggestive of PPROM or PROM should be confirmed with visual inspection and laboratory tests including ferning and nitrazine paper. • Management of PPROM at < 24 wks includes a discussion with the family reviewing the maternal risks against the fetal risks of significant morbidity and mortality during expectant management. • For women with PPROM or PROM in whom intrauterine infection, abruptio placenta, repetitive fetal heart rate decelerations, or a high risk of cord prolapse is present, immediate delivery is recommended. • Counseling after the delivery for the recurrence risk of PROM should occur, and modifiable risk factors addressed

23. References and Resources • APGO Medical Student Educational Objectives, 9th edition, (2009), Educational Topic 25 (p52-53). • Beckman & Ling: Obstetrics and Gynecology, 6th edition, (2010), Charles RB Beckmann, Frank W Ling, Barabara M Barzansky, William NP Herbert, Douglas W Laube, Roger P Smith. Chapter 22 (p213-217). • Hacker & Moore: Hacker and Moore's Essentials of Obstetrics and Gynecology, 5th edition (2009), Neville F Hacker, Joseph C Gambone, Calvin J Hobel. Chapter 12 (p150-153).