1. PreTerm PreLabour Rupture of Membranes Max Brinsmead PhD FRANZCOG February 2013

2. Preamble Defined as rupture of membranes before 37 completed weeks of gestation and not in labour Occurs in 1:50 pregnancies Associated with 40% of pre term births and a significant contributor to perinatal mortality. Deaths are due to… ▫Sepsis ▫Complications of prematurity ▫Lung hypoplasia Causes include: ▫Chorioamnionitis ▫At least 30% associated with positive bacterial cultures from amniotic fluid ▫Trauma e.g. after amniocentesis and CVS ▫Cervical incompetence ▫Connective tissue disorders ▫A large group are UNKNOWN

3. Diagnosis History ▫Listen carefully to the patient ▫Continuing loss of fluid important Examination ▫Sterile speculum ▫Do NOT perform a digital examination  Unless the patient is in labour Tests ▫Ultrasound  Look for oligohydramnios  Cervical length is best evaluated by PV scan ▫Amnisure is the best available test for amniotic fluid ▫A place for the detection of Phosphatidyl glycerol (surfactant)? ▫Take a vaginal swab for gram stain C/S

4. Possible Sequelae Cord Prolapse ▫Rare if there is a cephalic presentation ▫But always a risk with pre term breech and others ▫Can occur at any time Pre term delivery ▫At term 80% of patients will labour within 24-hr of SROM ▫This falls to <50% at earlier gestations ▫Labour can be silent and delivery precipitate Chorioamnionitis ▫Has both maternal and neonatal consequences ▫Organisms involved include…  Group B Haemolytic Streptococci (GBS)  E-Coli and other gram –ve coliforms  Less commonly anaerobic organisms, Chlamydia, Mycoplasma etc. Lung Hypoplasia and Compression Deformities ▫Rare if membranes rupture >28w

5. Management Admit for observation ▫Observation as an outpatient is an option if the fetus is pre-viable and the patient is capable of self-monitoring Observe for Signs of Chorioamnionits ▫Maternal temp and FHR 6 – 12 hourly ▫Watch for uterine tenderness & purulent liquor ▫Role of serial WCC or CRP is controversial ▫A limited role for amniocentesis and gram stain Monitor for Fetal Well-being ▫CTG – frequency and interpretation depends on gestation ▫A fetal tachycardia has a high correlation with infection ▫Ultrasound biophysical profile & Dopplers – limited role ▫The amount of AF seen (& fetal breathing) is the best predictor of lung development for very early PPROM Prophylactic Antibiotics ▫Erythromycin or Clindamycin prolongs the PROM-Delivery interval and improves early but not long term neonatal outcomes ▫Amoxil increases the risk of neonatal NEC after pre-term delivery

6. Management (2) Antibiotics (cont’d) ▫Erythromycin 250 mg 6-hourly for 10 days recommended ▫Consider Penicillin 3G IV stat if GBS is found Corticosteroids ▫Are indicated from the time of viability to 35w ▫May be repeated at least once. They are effective for only 7 days Tocolysis ▫Not recommended prophylactically ▫But do have a role in delaying delivery to allow steroids effect and to transfer the patient to a safe place for delivery ▫Contraindicated (and often ineffective) if there is infection Timing of Birth ▫When neonatal facilities are optimal there is little point in prolonging the gestation beyond 34 completed weeks ▫When to transfer a pre-viable PROM can be a dilemma Amnioinfusions and Fibrin Glues ▫Unproven

7. Corticosteroids Effectively reduce the risk of: ▫Hyaline membrane disease ▫Necrotising enterocolitis ▫Intracranial haemorrhage ▫Death and disability Are safe in the short and long term Are effective at gestations 26w – 40w Do not increase the risk of fetal or maternal infection Must be given within 24 hrs and 7 days Repeat once if <34 weeks or still high risk Optimum formulation, dose & route – uncertain  I prefer IM Betamethasone 11.2 mg 24 hours apart Remember also Mg sulphate for 24 hours before birth to be effective

8. Infection and Prematurity Subclinical infection implicated in 40-70% of pre term labour Also has a sinister role in the aetiology of cerebral palsy The results of therapeutic trials of antibiotics in preventing pre term birth are conflicting Vaginosis is a risk factor for prematurity ▫But screening and treatment should be reserved for those at risk ▫Most studies have focused on anaerobic BV but aerobic BV may be the more important Erythromycin or Clindamycin is useful after PROM Do not use Amoxil (Increases the risk of NEC) Antibiotics with intact membranes may increase risk of perinatal mortality (RR 1.52, CI 0.99-2.34) and increases the risk cerebral palsy (RR 1.18, CI 1.02-1.37) Is the source of infection outside the genital tract?