1. 8th Edition APGO Objectives for Medical Students
Premature Rupture of Membranes

2. Objectives The student will be able to describe:
History, physical findings and diagnostic methods to confirm rupture of the membranes
Factors predisposing to premature rupture of membranes
Risks and benefits of expectant management versus immediate delivery
Methods to monitor maternal and fetal status during expectant management
Predicted outcome when premature rupture of membranes occurs at a preterm gestation

3. Preterm PROM Definition
preterm premature rupture of membranes (PPROM) is defined as amniorrhexis before 37-wk. gestation
premature ROM is defined as rupture of the chorioamnionic membranes prior to the onset of labor
prolonged ROM usually refers to ROM for more than 24 hours

4. Preterm PROM
Incidence
1-3% - PPROM
10% - PROM (at term)

5. Preterm PROM Diagnosis History Physical Test
Gush of fluid
Constantly wet
Physical
Pooling fluid - posterior fornix
Fluid per os
Examine with sterile speculum to prevent/limit digital exam of cervix, to minimize risk of ascending infection and amnionitis
Test
Fern - cervical mucus broad fern vs. amniotic fluid narrow fern
pH (Nitrazine) - turns blue
Cervicovaginal fetal fibronectin > 50 ng/ml
Ultrasound - compatible with SROM

6. Preterm PROM Etiology Spontaneous Iatrogenic Infections
Decreased collagen content
Higher surface energy
Elevated vaginal pH due to anaerobes, i.e. Bacterial vaginosis
Nutritional deficiencies
Vitamin C
Zinc
Copper
Infections
S. Aureus
Chlamydia
GBS
Neisseria gonorrhoeae
Bacteroides sp
Smoking
Iatrogenic

7. Preterm PROM Risk Factors Previous preterm PROM Incompetent cervix
Nutritional factors (see above)
Alterations in vaginal pH
Infections
Coitus
Smoking
Multiple gestation

8. Previable PPROM (< 24 wk. gestation)
Summary of Published Studies Concerning Preterm Previable PROM
Latency (time to delivery)
Mean days 16
Median days 6
Total n = 476
Outcomes
Amnionitis 42%
Endometritis 15%
Delivery within
7 days 62%
14 days 80%
28 days 90%
Survival
< 20 wk 33% (few numbers)
wk 25% (realistic)
wk 50%

9. Previable PPROM (< 24 wk. gestation)
Prolonged PROM
Skeletal deformities
< 26 wk. (27%)
27-33 wk. (6%)
Pulmonary hypoplasia
27-33 wk. (1.4%)

10. Previable PPROM (< 24 wk. gestation)
Complications of prolonged PPROM
Pulmonary hypoplasia
Orthopedic anomalies
Potter facies
Fetal growth restriction

11. PROM > 26 wk. and < 34 wk. Maternal effects
Increase in chorioamnionitis
Increase in Cesarean delivery
Twins
Breech
Fetal heart rate decelerations
Spontaneous labor in ~ 90% within 48 hr. of membrane rupture
Increased risk of placental abruption

12. PROM > 26 wk. and < 34 wk. Fetal effects Increase in RDS
Increase in intraventricular hemorrhage
Increase in neonatal sepsis and subsequent cerebral palsy
Increase in perinatal mortality
Increase in cord prolapse

13. PROM > 26 wk. and < 34 wk. Management
Expectant - bed rest in hospital
Antibiotics
Prophylaxis for prevention of GBS in neonate
Prophylactic antibiotics
May prolong latent period by an average of 5-7d 
May reduce maternal amnionitis and neonatal sepsis

14. PROM > 26 wk. and < 34 wk. Management Steroids Tocolytics
To enhance fetal lung maturation and decrease RDS
Only one round per NIH Consensus
Tocolytics
Randomized trials have shown no pregnancy prolongation

15. PROM > 26 wk. and < 34 wk. Management Resealing of membranes
11% show reaccumulation of fluid
Once confirmed may discharge patient home
Deliver for
Clinical infection
Irreversible non-reassuring fetal heart rate pattern
Advanced labor Gestational age >34 weeks

16. PROM > 26 wk. and < 34 wk. Conclusion
Steroids decrease incidence of RDS
Tocolytics do not significantly prolong pregnancy, but may prolong period in which to give steroids
Antibiotics during latency period improve neonatal outcome

17. References
Adapted from Association of Professors of Gynecology and Obstetrics Medical Student Educational Objectives, 7th edition, copyright 1997.

18. Premature Rupture of Membranes
Clinical Case
Premature Rupture of Membranes

19. Patient presentation
A 29-year-old infertility patient with a triplet gestation at 29 weeks gestation presents to the labor and delivery unit of your hospital describing a sensation of “leaking fluid from the vagina” for the last minutes. She says she noted her underclothes were damp yesterday, and this morning she noted clear fluid with a small amount of blood leak from her vagina after voiding and wiping her perineum. She denies fever, contractions and abdominal pain, and feels the babies are moving normally.

20. Patient presentation
Physical examination reveals an afebrile, alert, anxious female. Abdominal examination reveals a 32-centimeter fundal height and a non-tender abdomen and uterus.
How should you further assess this patient?

21. Teaching points Why is preterm birth risky?
Survival by gestational age*
< 23 weeks = 0-12%
23 weeks = 2-36%
24 weeks = 17-56%
25 weeks = 35-85%
*Represents livebirth
Hack and Fanaroff; Semin Neonatol 2000; 5:89-106

22. Teaching points Why is preterm birth risky?
Survival by birth weight*
< 500 g = 1-38%
g = 4-37%
g = 27-63%
g = 43-88%
*Represents livebirth
Hack and Fanaroff; Semin Neonatol 2000; 5:89-106

23. Discussion
In addition to the risks of prolonged rupture of membranes in a preterm gestation, the risk of preterm birth makes PROM a difficult situation. When PROM occurs at a previable gestation, a discussion should be held with the family reviewing the maternal risks of infection against the fetal risks of significant morbidity and mortality during expectant management. When PROM occurs at a preterm, but potentially viable, gestation, discussion should ensue regarding the risk of fetal and maternal infection, as well as risks of preterm birth. This will allow the family to understand the benefit of antibiotics, steroids and expectant management. Careful monitoring of mother and fetus during expectant management should be undertaken, and delivery considered when documented or suspected lung maturity or signs of fetal infection, unrelieved fetal stress or advanced labor are noted. Counseling after the delivery for the recurrence risk of PROM should occur, and modifiable risk factors addressed.

24. References
American College of Obstetricians and Gynecologists Practice Bulletin # 1, Premature Rupture of Membranes, Washington, DC: ACOG, June 1998.
Alexander JM, Mercer BM, Miodovnik M, Thurnau GR, Goldenberg RL, Das AF, Meis PJ, Moawad AH, Iams JD, Vandorsten JP, Paul RH, Dombrowski MP, Roberts JM, McNellis D. “The impact of digital cervical examination on expectantly managed preterm rupture of membranes” Am J Obstet Gynecol 2000 Oct;183(4):
Mercer BM, Miodovnik M, Thurnau GR, Goldenberg RL, Das AF, Ramsey RD, Rabello YA, Meis PJ, Moawad AH, Iams JD, Van Dorsten JP, Paul RH, Bottoms SF, Merenstein G, Thom EA, Roberts JM, McNellis D. “Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. JAMA 1997, Sep 24; 278(12):