Induction and augmentation Flashcards
what is augmentation of labour
speeidng up labour that is already established if not progressing, usually using oxytocin infusion
eg waters broken but no contractions
when is augmentation of labour indicated in the active phase of the 1stage
when cervical dilatation is not increasing by 0.5cm/hr in PG and 1cm/hr in MG
what can be done a few days before IOL to increase likelihood of success
membrane sweep - causes release of PG
what is the Bishop score
assess how the cervix will respond to IOL
how are al the measurements for Bishop score taken
on vaginal examination
what are the cut offs for Bishop score for a likely good response and bad response to IOL
<4 - not likely to progress naturally
>6 - likely to respond to interventions to induce labour
what is the first step in IOL
vaginal prostaglandins - these ‘ripen’ the cervix by softening the collagen fibres
when do you move onto the 2nd step of IOL
repeated vaginal PG application until the Bishop score is >6
where are the PG inserted
into the posterior fornix
2nd step of IOL
amniotomy - artificial rupture of membranes using a stick with a pointed hook on the end
do you need to use vaginal PG before amniotomy
no you can go straight to amniotomy if cervix is ripe enough on first examination (Bishop score)
what complications can arise from amniotomy
- bleeding
- failure
- placental abruption
- amniotic fluid embolism - pulmonary embolism = shock, dyspnoea, bleeding
3 rd step in IOL
IV oxytocin infusion - start lower and increase until uterus is contracting regularly around 4 times/10 minutes
what is syntometrine
oxytocin and ergometrine, the latter is also an arterial vasoconstrictor, this raises blood pressure so is CI in patients with PVD, hypertension, heart disease
how many contractions in 10 mins is hyperstimulation
>5
what are the dangers of foetal hyperstimulation
- as normal contractions cause transient foetal hypoxia, too many/strong results in foetal hypoxia –> CTG and FBS if indicated
what is another complciation associated with oxytocin infusion
rupture of uterus - more likely if PG, previous C section
what are 3 options if IOL fails
- Repeat vaginal prostaglandins
- Mechanical dilatation
- C section
what is the main cause for IOL
post term gestation - after 42 weeks the risk of plcaenetal insufficinecy and stillbirth greatly increases
diabetes and IOL
baby is at risk of stilllbith and neonatal hypoglycaemia, this risk increases more beyond term
IOL may be indicated around 38 weeks if mother has poor glycaemic control or there is evidence of macrosomia
maternal age and IOL
increased risk of stillbirth >40 weeks
reduced foetal movements and IOL
can be a sign of placenetal insufficinecy etc
multiple pregnancy and IOL
DCDA want to deliver by 38 weeks and MCDA by 36 weeks (+ steroids) because there is a higher rate of still birth
rupture of membranes and IOL
there is a risk of ascending infection
if baby is v premature (34 weeks) leave it for a bit (prematurity risk>infection)
if >37 weeks - IOL (infection risk>prematurity)
