PRELABOUR RUPTURE OF MEMBRANES

(PROM)

Sunil Kumar Daha

DEFINITIONThe spontaneous rupture of the fetal membranes any time beyond the 28th week of pregnancy but before the onset of labor.

* After 37th wks - Term PROM * before 37 wks - Preterm PROM

Rupture of membranes for > 24 hours before delivery is called prolonged rupture of membranes

American college of Obstetricians and Gynaecologists

INCIDENCE5-10% of all deliveries (8% at term and 2% preterm)

PROM at term*Unfavorable Cervix - the majority of women labour

spontaneously within 12 hours

*50 % will be in labour after 12 hours

*86 % will be in labour within 24 hours

*94 % will be in labour within 48 – 95 hours

*6 % of women will not start labour within 96 hours of PROM Preterm PROM complicates 2% to 20% of all deliveries and is associated with 18% to 20% of perinatal deaths. 

South Australian Perinatal Practice Guideline

RISK FACTORS Intrauterine Infections ( UTI, chorioamnionitis, lower

genital tract infections) – Major predisposing factor Low socioeconomic status Body mass index ≤ 19.8 Nutritional deficiencies Cigarette smoking History of previous PROM or PPROM Polyhydramnios Multiple pregnancy : Nearly 40% of twin pregnancy

will have PROM or PPROM Cervical incompetence

PathophysiologyRupture of the membrane near the end of pregnancy (Term) may be caused by the natural weakening of the membrane or by the force of uterine contraction .

PPROM is often due to an infection in the uterus.Reduced tensile strengthIncreased friabilityResealing *14% midtrimester PROM eventually stop leaking presumably

due to “resealing” of fetal membrane*Cessation is probably not due to actual repair and

regeneration of membranes but rather to changes in the decidua and myometrium that block further leakage

DIAGNOSISHistory* The only subjective symptom is escape of watery discharge per vagina either in the form of a gush or slow leak

Examination1.Speculum examinationUpon sterile speculum examination, ruptured membranes are diagnosed if * Amniotic fluid pools in the posterior fornix* If clear fluid flows from the cervical canal(If the fluid is not immediately visible, the woman can be asked to cough to provoke leakage)

2. NITRAZINE TEST*The pH of vaginal secretions normally ranges from 4.5 to 5.5, whereas that of amnionic fluid is usually 7.0 to 7.5

*The indicator nitrazine paper is used to identify ruptured membranes

*Test papers are impregnated with the dye, and the color of the reaction between these paper strips and vaginal fluids is interpreted by comparison with a standard color chart

*Nitrazine paper turns from yellow to blue at pH > 6

3.FERNING PATTERN*Microscopic ferning of the amniotic fluid on drying. *Amniotic fluid crystallizes to form a fernlike pattern due to its relative concentrations of sodium chloride, proteins, and carbohydrates4. Nile blue testCentrifuged cells stained with 0.1% Nile blue sulphate- Orange blue coloration of the cells

*Other Tests1.Ultrasound: fluid levels are low2. Immune-chromatological tests (AmniSure,

Actim PROM test): These are commercially available test kits that detect chemicals present in amniotic fluid.False-positive rate is 19-30%.

3. Indigo carmine dye test: A needle is used to inject indigo carmine dye (blue) into the amniotic fluid. In the case of PROM, blue dye can be seen on a stained tampon or pad after about 15–30 minutes. This method can be used to definitively make a diagnosis, but is rarely done because it is invasive and increases risk of infection.

Investigations1. Full blood count

2. Urine for routine analysis and culture

3. High vaginal swab for culture

4. Vaginal pool for estimation of phosphatidyl glycerol and L: S ratio

5. Ultrasonography for fetal biophysical profile

6. Cardiotocography for nonstress test

Complications

IMMEDIATE RISK cord prolapse, cord compression and placental abruption.

DELAYED RISK Dry LabourHigh Caesarean section rate Clinical chorioamnionitis Intrapartum fever* Postpartum fever* Antibiotics before/during labour*

Fetal Pulmonary hypoplasiaNeonatal sepsisRDSIntraventricular HaemorrhageNecrotising enterocolitis Increased NICU stay* High Perinatal morbidity (CP)

*Chorioamniotis is diagnosed if

FeverUterine tendernessOffensive vaginal dischargeFetal or Maternal Tachycardia Leucocytosis (>15*10^9/L)C Reactive protein >40

Management1. Gestational Age

2. Presence/Absence of labor

3. Fetal presentation(Breech and transverse lies are unstable and may increase risk of cord prolapse)

4. FHR tracing pattern

5. Presence or absence of maternal/fetal infections

6. Fetal lung Maturity

7. Availability of neonatal intensive care

Treatment

PPROMErythromycin should be given for 10days following the diagnosis of PPROM.

• Statistically significant reduction in chorioamnionitis• Reduction in the number of babies born within 48hrs and 7

days• Reduced neonatal infections• Delays the delivery thereby allowing sufficient time for

prophylactic prenatal corticosteroids to take effect.

Antenatal corticosteroids• Indicated in women with PPROM between 24 and 34 weeks of gestation

•Betamethasone 12 mg given intramuscularly in two doses or dexamethasone 6 mg given intramuscularly in four doses are the steroids of choice to enhance lung maturation.

Delivery•34 weeks of gestation•expectant management >34 weeks – increased risk of chorioamnionitis and decreased risk of respiratory problems in neonate.

Green top Guideline No. 44 (october 2010)

PPROM

Term PROMActive ManagementLabour does not establish after a latent period of 4 hours - an oxytocin infusion should be started but in an unfavorable cervix, prostaglandins may have an important role.

Regardless of any clinical factors, women at term who have rupture of the membranes for >18 to 24 hours should commence parenteral antibiotic cover

Woman known to have vaginal GBS colonization, Intrapartum antibiotic prophylaxis and early induction of labour is recommended.

Intrapartum antibiotics

PROM > 18 to 24 hours*Parenteral antibiotic cover for GBS is required in all cases

(irrespective of GBS status) of PROM > 18 to 24

*Give benzyl penicillin 3 g IV loading dose, then 1.2 g IV every 4 hours until delivery

*If allergic to penicillin, clindamycin 600 mg IV in 50 – 100 mL over at least 20 minutes every 8 hours

Expectant ManagementCriteria• Term PROM with fixed cephalic presentation• Group B streptococcus (GBS) negative• No signs of infections• Normal CTG• No history of digital vaginal examination, cervical suture• Adequate resource/ staffing to provide support as an

outpatient or inpatient• Commitment to 4 hourly maternal temperature, evaluation

of vaginal loss and assessment of fetal well being.

Carefully selected to ensure they not only meet the criteria but also live close to the hospital, have adequate support at home and dependable transport.

Chorioamnionitis

Check for any other site of infection (e.g. urinary or respiratory tract) which could cause these changes

If chorioamnionitis is confirmed, delivery of the fetus is indicated

Commence ampicillin (or amoxicillin) 2 g IV initial dose then 1g IV every 6 hours, gentamicin 5 mg / kg IV daily, metronidazole 500 mg IV every 12 hours

If allergic to penicillin, give clindamycin 600 mg IV every 8 hours and gentamicin 5 mg / kg IV daily

References•Green top guidelines of Royal college of obstetrician and gynaecologists- No 44 October, 2010

• Term PROM :Royal Australian and new Zealand college of obstetricians and gynaecologists, C obs -36. March 2014

•South Australian Perinatal Practice Guideline. September 2015

•Preterm labour, Williams obstetrics 24th edition•L Alabi Isama & A Ugwumadu. Preterm Birth. Aria’s Practical guide to high risk pregnancy and delivery 4th edition, 2015, 135-140

•H Konar. Preterm labour, Preterm rupture of membranes,postmaturity, IUD of fetus.DC Dutta’s textbook of obstetrics. 7th edition. Nov 2013: 314-326.

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