Premature rupture of membranes (PROM) Flashcards
Define PROM.
Spontanous rupture of membranes in the absence of uterine contractions after 37w
What are the risk factors for PROM?
Prior preterm birth
Cigarette smoking
Polyhydramnios
Urinary and sexually transmitted infection
Prior PROM
Low BMI
Summarise the epidemiology of PROM.
8% of pregnancies
What are signs and symptoms of PROM?
Sudden gush of fluid PV, followed by constant trickle
What investigations should be performed for PROM?
General: Assess signs of infection (fever, tachy)
Vaginal: Avoid bimanual if poss!
Speculum: confirm pooling of liquor in vagina
TVUSS: cervical length <15mm?
Foetal Fibronectin (FFN)
What is the management for PROM?
Admit for 4 hourly temperature + 24h fetal monitoring.
If clear liquor: expectant Mx for 24h, if >24h –> IOL
If meconium stained/ known GBS: IOL asap +
Abx: benzylpenicillin
Postnatal: Observe neonate for 12h minimum.
What are complications associated with PROM? What is the prognosis for PROM?
Increased risk of ascending infection.
60% labour within 24h.
Define preterm labour
Regular contractions of the uterus resulting in changes in the cervix that start before 37w of pregnancy.
Give 6 major causes of neonatal morbidity arising from preterm birth
Intraventricular hemorrhage grade
Seizures
Hypoxic-ischemic encephalopathy
Necrotizing enterocolitis
Bronchopulmonary dysplasia
Persistent pulmonary HTN
Give 3 minor causes of neonatal morbidity arising from preterm birth
Hypotension requiring Tx
Respiratory distress syndrome
Hyperbilirubinemia requiring Tx
How is preterm birth classified?
extremely preterm: <28w
very preterm: 28-32w
moderate to late preterm: 32 to <37w
Wha† is threatened pre-term labour?
uterine contractions but without cervical dilatation
Give 5 risk factors for pre-term labour
Infection
Hx preterm delivery
Multiple pregnancy
Preterm premature rupture of membranes
Problems with the uterus, cervix or placenta
What surgery can increase chance of preterm labour?
LLETZ
Give 5 maternal risk factors for preterm laobur
HTN / DM
Smoking
IVDU
Underweight/ overweight before pregnancy
Stressful life events
Give 2 prophylactic measures to prevent preterm labour
Vaginal progesterone: start between 16-24w + continue to at least 34w
Cervical cerclage between 12-14w
In which women are prophylactic measures to prevent preterm labour indicated?
Hx spontaneous preterm birth (up to 34+0w) or mid-trimester loss (from 16+0w onwards)
+
Results from TVUSS between 16+0 and 24+0w that show cervical length of ,<25 mm
What are the indications and contraindications for rescue cerclage?
Cervical dilatation in absence of contractions before 23w + unruptured membranes
CI: Bleeding, infection, uterine contractions
What investigations are used for preterm labour?
Pelvic exam (speculum, digital examination)
CTG
TVUSS
Lab tests
If clinical assessment suggests preterm labour when ,<29+6 w, what action should be taken?
Tx for preterm labour
If clinical assessment suggests preterm labour when >,30w what action should be taken?
TVUSS measure cervical length
> 15mm: unlikely in preterm labour
,<15mm: Tx for preterm labour
Describe management for preterm labour
Admit to antenatal ward
Maternal corticosteroids to accelerate fetal lung maturation
Tocolytics to delay delivery long enough for steroid administration/ transfer to specialised unit
IV magnesium sulphate for neuroprotection of neonate if birth expected in next 24h
What steroids are given in preterm labour?
IM Betametasone in 2 divided doses of 12mg 24h apart
or Dexamethasone in 4 divided doses 6mg every 12h
What Tocolytics are used in preterm labour?
1st line: Nifedipine (calcium channel blocker)
2nd line: Atosiban (Oxytocin receptor antagonist)
Why must caution be taken when giving magnesium sulphate? What can be done?
Toxicity results in resp depression + arrhythmias
Monitor every 4h: obs + deep tendon reflexes
Antidote: 10ml 10% calcium gluconate over 10 mins + stop MgSO4
If TVUSS is indicated for >,30w pregnancies, but not available what investigation should be performed?
Fetal fibronectin
Determines likelihood of birth within 48h
What is fetal fibronectin?
Protein produced by fetal cells
Found at interface of chorion + decidua
“biological glue” binding fetal sac to uterine lining
leaks into vagina if pre-term delivery likely
How is a fetal fibronectin test taken?
To avoid false +ve: before pelvic exam + TVUSS
Speculum + swab
4 things that increase risk of false +ve in fetal fibronectin test
ROM
Recent SI
PV bleeding
Recent cervical manipulation
Interpret results of fetal fibronectin test
-ve = conc. ,<50 unlikely in preterm labour
+ve= con >50 preterm labour likely: steroids + tocolysis
What does a negative fetal fibronectin indicate?
Highly unlikely for preterm labour in next 14d
Define premature pre labour rupture of membranes
Spontaneous rupture of membranes prior to onset of labour <37w
What investigation is used for PPROM?
Speculum
If pooling of amniotic fluid- offer care consistent with PPROM
If no pooling of amniotic fluid, perform diagnostic testing
USS estimation of amniotic fluid vol can give helpful additional info
What diagnostic testing is performed if there is no pooling of amniotic fluid in suspected PPROM?
Insulin like growth factor binding protein-1 test
or
Placental alpha- microglobulin-1 test of vaginal fluid
Describe management of PPROM
Admit
Prophylactic Abx
Intense surveillance for chorioamnioitis or preterm labour
Maternal corticosteroids
IV Magnesium sulphate if birth expected in 24h
DO NOT administer Tocolytics
What prophylactic antibiotics are used in PPROM?
Erythromycin PO 250mg QDS for max. 10 days or until in labour (whichever sooner)
2nd line= Penicillin PO
Why should tocolytics be avoided in PPROM?
Increased risk of infection
If >34w and positive group B strep at any point in current pregnancy, how should a woman with PPROM be managed?
Immediate IOL
What can be measured to assess for chorioamniotis in PPROM?
Clinical assessment
Maternal CRP + WCC
Fetal + Maternal HR
