Premature Rupture of Membranes

UNC School of Medicine Obstetrics and Gynecology Clerkship Case Based Seminar Series

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

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

Incidence

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

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

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

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

 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: 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

Management: PPROM

(< 24 wk gestation – “previable”)      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

Gestational Age (In Completed Weeks) Death Before NICU Discharge

Death

Outcomes at 18 to 22 Months Corrected Age*

Death/ Profound Neurodevelopmental Impairment Death/Moderate to Severe Neuro developmental Impairment

22 Weeks 23 Weeks 24 Weeks 25 Weeks

  95% 74% 44% 24% 95% 74% 44% 25% 98% 84% 57% 38% 99% 91% 72% 54% 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

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

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

Management: PROM

(> 34 wk gestation)   Proceed to delivery  Induction of labor GBS prophylaxis

Management: Rationale

  Corticosteroids  Enhance fetal lung maturity  Decrease risk of RDS, IVH, and necrotizing enterocolitis  Antibiotics  Prolong latency period  Prophylaxis of GBS in neonate  Prevention of maternal chorioamnionitis and neonatal sepsis Tocolytics   Delay delivery to allow administration of corticosteroids Controversial, randomized trials have shown no pregnancy prolongation

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

Management: Amniocentesis

  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 Courtesy of Thomas Shipp, MD.

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)

Management: Surveillance

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

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

Expectant Management vs. Preterm Delivery

  Preterm Delivery Risks: use NICHD calculator http://www.nichd.nih.gov/about/org/cdbpm/pp/prog_ep bo/epbo_case.cfm

Gestation (w)

25 24 23 22

Weight

550 500 450 401g

Sex

Female Male Male Female

Steroids Survival

Yes Yes Yes No 64% 35% 16% 2%

Survival w/o profound ND impairment

50% 22% 9% 1%

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

References and Resources

 APGO Medical Student Educational Objectives, 9 th 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).