Induction of Labour Flashcards
How many labours are induced?
10-20%
Success rate 60-80% at term
Indications for induction
Uteroplacental
Insufficiency (one of the most common), Prolonged Pregnancy, IUGR, Oligo or Anhydramnios,
Abnormal CTG, PROM, Severe Pre-Eclampsia or Eclampsia after maternal stabilisation, Intrauterine Death, Antepartum Haemorrhage at term,
Chorioamnionitis; Macrosomia is a controversial indication
Medical Indications for Induction
Severe HTN, Uncontrolled DM, Renal Disease or Malignancy
Predictors for successful induction
Gestational Age, Parity, Bishop’s Score
Mechanical Induction
Separation of Membranes from Cervix leads to Local release of Prostaglandins;
Artificial Separation (=Stretch and Sweep); 30% into Spontaneous labour <7 days, in majority
it improves Bishop score
Prostaglandins
Prostaglandins (PGE2 =Dinoprostone) – Intravaginal into Posterior Fornix as gel or tablet
o CTG should be performed 30 minutes before, and after insertion to confirm wellbeing and detect Hyperstimulation; Additional doses if still not favourable after 6hrs; Multiparous seldom need more than one dose
o Oxytocin should not be started for 6hrs to avoid Uterine Hyperstimulation
Oxytocin Infusion
Increases Cervical Prostaglandin levels and initiating Uterine Contractions with Myometrial receptor activation
o Best used when membranes have ruptured (either PROM or Amniotomy)
o Low dose (1-4 mIU/min); Doubled every 40 mins to achieve optimal contractions
o Continuous CTG monitoring; Sensitivity of Myometrium to Oxytocin increases during
labour, so rate needs to be revised
Amniotomy
Releases Local Prostaglandins causing Cervical Ripening and Myometrial Contractions; If not initiated or no cervical changes after 2hrs, Oxytocin infusion commenced