Normal Labour Flashcards
What is labour?
Labour is the process in which the foetus, placenta and membranes are expelled via the birth canal.
When does normal labour usually occur
In normal labour occurs spontaneously, at term (37-42 weeks gestation), with the foetus presenting by the vertex and results in a spontaneous vaginal birth (SVD)
How is labour triggered?
By paracrine and autocrine signals generated by maternal, foetal and placental factors which interplay
What are the key physiological changes which must occur before expulsion of the foetus will occur?
- Cervix softens
- Myometrial tone changes to allow for coordinated contractions
- Progesterone decreases whilst oxytocin and prostaglandins increase to allow for labour to initiate
What is the latent first stage of labour?
- longest part
- intermittent, often irregular painful contractions
- which bring about some cervical effacement and dilatation up to 4cm
What is the active first stage of labour?
- regular, painful contractions
- result in progressive effacement and cervical dilatation from 4cm
When is the first stage of labour complete?
When the cervix is fully dilated (10cm)
How long does the first stage of labour last?
varies between women
- for a primagravida: avg. 8 hours (unlikely to last longer than 18 hours)
- for a multigravida: avg. 5 hours (unlikely to last over 12 hours).
How fast does the first stage of labour progress?
0.5-1cm per hour
How does the cervix thin and dilate?
uterine contractions
- start at the fundus and move down and across
- exert pressure on fetal pole
- encourages flexion
- pressure on the cervix to thin and dilate
What does stage 2 of labour encompass?
From full cervical dilatation to the birth of the baby
What is the passive second stage of labour?
full dilatation of the cervix
before or in the absence of involuntary expulsive contractions
What is the active second stage of labour?
expulsive contractions with a finding of full dilatation of the cervix
How long should the second stage of labour last?
primagravida birth: two hours
multigravida birth: one hour
What is the third stage of labour?
Time from the birth of the baby to the expulsion of the placenta and membranes
What does active management of the third stage of labour involve?
Package of care
- uterotonic drugs
- deferred clamping and cutting of the cord
- controlled cord traction after signs of separation of the placenta
What does physiological management of the third stage of labour involve?
Package of care
- No routine use of uterotonic drugs
- No clamping of the cord until pulsation has stopped
- Delivery of the placenta by maternal effort
When is the third stage of labour considered delayed?
- If not completed within 30 minutes of the birth with active management
- If not completed within 60 minutes of the birth with physiological managemnet
How should progress be monitored during labour?
- maternal observations: blood pressure, pulse, temperature, respirations, oxygen saturation, urine output and urinalysis
- abdominal palpation
- vaginal examination
- monitoring of liquor
- auscultation of the foetal heart
- palpation of the uterine muscle contractions
- external signs
What is abdominal palpation used to assess?
- foetal lie
- foetal presentation
- foetal position
- foetal engagement
What is vaginal examination used to assess?
- foetal presentation
- foetal position
- engagement and station
- cervical effacement and dilatation
- presence/ absence of membranes
How is the foetal heart auscultated
- Intermittently with handheld Doppler or Pinards
- Continuosly with CTG
When is intermittent monitoring of babies heartbeat carried out?
- Every 15 minutes in the first stage of labour
- Every 5 minutes in the second stage of labour
Where should information be recorded during labour?
Partogram
