Preterm Labour Flashcards
Define pre-term labour
Onset of labour (regular, painful contractions a/w progressive cervical changes with/without ROM)
List some complications of PTL more significant in gestations
HMD, ICH, infections, NEC
Outline the management principles of PTL
Assess gestationEstablish the diagnosisAscertain a causeDecide on tocolysis/steroids
Define tocolytic
Drug used to suppress labourIn order to administer steroids to enhance fetal lung maturity
For how long are tocolytics continued?
48 hrs
What is the dosage of nifedipine (tocolytic drug of first choice and CCB, ‘Adalat’) used in PTL?
Initially: 30mg orally then 20mg after 90minIf contractions persist: 20mg 6hrly
What are two NBC/I’s to CCB (Nefidipine, ‘Adalat’)?
HypovolaemiaCardiac conditions
What is the MOA of B2 adrenergic agents (e.g. salbutamol, ‘Ventolin’) as a tocolytic agent, and what are some of its S/E’s?
Uterine smooth muscle relaxantMaternal and fetal tachycardia, hyperglycaemia
What are some common S/E’s of CCB (e.g. nefidipine, ‘Adalat’)tocolysis?
HeadacheFlushingNausea
What is the dosage of salbutamol (Ventolin) used for tocolysis?
250mcg diluted in 9.5mL water as slow IV bolus
What are 4 NB C/I to B2 adrenergic tocolysis?
Stenotic valvular lesionsShockDMThyrotoxicosis
What is the MOA of prostaglandin antagonists (e.g. indomethacin) in tocolysis?
Blocks the conversion of AA to prostaglandin E2 and F2α
What is the dosage of indomethacin used in tocolysis?
100mg rectally 12hrly for 48hrs
What are S/E’s of prostaglandin antagonists (e.g. indomethacin) in tocolysis?
GIT irritationRFSupression of platelet functionPremature closure of ductus arteriosus
What are 3 NB C/I to prostaglandin antagonist (e.g. indomethacin) tocolysis?
ThrobocytopaeniaPeptic ulcer diseaseFetal gestation > 32 wks
Name the tocolytic not used in state hospitals (expensive) and outline its MOA
AtosibanOxytocin receptor antagonist (blocks oxytocin reeptors in the uterus)
When may a rescue course of steroids be given?
If the initial dose is given at very early gestation (e.g. 27 wks)
What did the ORACLE III trial show wrt antibiotic use in PTL?
No benefit except in those in whomROM had also occurred
Define prelabour preterm ROM (PPROM)
Leakge of amniotic fluid through the cervixMust be differentiated from heavy vaginal dischargeor involuntary passage of urine
List 7 causes of ROM
- intra-uterine infection2. Incompetent cervix3. Iatrogenic ROM (IOL)4. Interference (a/winfection)5. Complication of amniocentesis6. Complication of ECV7. Uterine overdistension (e.g. polyhydramnios, multiple pregnancy)
Outline the management principles of PPROM
> 35wks: deliver
Outline the conservative management of PPROM
Bed restSterile pads changed 2hrlyAvoid PV’sAdminster steroidsAssess fetal growth, amniotic fluidMonitor for signs of maternal infection (CTG, clinical exam,twice weekly WCC + CRP)Oral antibiotics e.g. erythromycinDeliver if signs of intrauterine infection or fetal distress
