Normal Labour Flashcards
(33 cards)
How is labour defined?
- the physiological process in which a foetus is expelled from the uterus
- it requires the presence of regular uterine contractions
- these increase in frequency, intensity + duration
- this leads to progressive cervical effacement + dilatation
labour = regular contractions + cervical effacement / dilatation
other features (e.g. waters breaking) do NOT indicate labour
When does labour + delivery typically occur?
between 37 and 42 weeks gestation
Why is the position of the baby important during labour?
- the head pushes against the cervix, causing it to stretch
- stretching of the cervix sends nerve impulses to the brain
- the brain stimulates the pituitary gland to release oxytocin
- oxytocin causes the uterus to contract
if the baby is not in the correct position, the head is unable to cause the cervix to stretch
What are the 2 phases of labour?
- latent phase
- established phase
the established phase is further divided into 3 stages
What happens during the latent phase of labour?
- there may be some painful contractions, but these are irregular
- there may be some cervical effacement and dilation up to 4cm
- this phase can last from hours up to a week
during this phase women are encouraged to mobilise, use paracetamol and stay hydrated
What is meant by the established phase of labour?
- there are regular painful cervical contractions
- there is progressive cervical dilatation from 4cm
How can established labour be divided into 3 stages?
first stage:
- from the onset of labour (4cm dilation / true contractions) until 10cm dilation
second stage:
- from 10cm dilation to delivery of the baby
third stage:
- from delivery of the baby until delivery of the placenta
What is the first stage of labour?
- this begins when the cervix reaches 4cm dilation and true contractions begin
- there is cervical dilatation (up to 10cm) and effacement
effacement = cervix becomes thinner
What is meant by cervical effacement?
- also referred to as “ripening”
- the cervix becomes softer, thinner and shorter
it is assessed via a digital examination
- finger inserted into the cervical os to assess how dilated / effaced the cervix is
What is meant by the “show”?
- there is a mucus plug in the cervix that prevents bacteria from entering the uterus during pregnancy
- this falls out during the first stage of labour
- this creates space for the baby to pass through
this appears as a single blob of pinkish / white jelly which can be blood-tinged
What are the signs of the onset of labour?
- show (mucus plug from the cervix)
- rupture of membranes
- regular, painful contractions
- dilation of the cervix on examination
What are the criteria for diagnosing the latent and established first stage of labour?
latent stage:
- painful contractions
- effacement + dilation of the cervix up to 4cm
established phase:
- REGULAR, painful contractions
- dilation of the cervix from 4cm onwards
What are Braxton-Hicks contractions?
- occassional irregular contractions of the uterus
- felt during the 2nd or 3rd trimester
- there is temporary and irregular tightening / mild cramping in the abdomen
they are sometimes called “false labour pains” and can be described to feel like menstrual cramps
How are Braxton-Hicks contractions related to labour?
- these contractions are NOT true contractions and DO NOT indicate the onset of labour
- they do not progress
- they do not become regular
staying hydrated / relaxed can reduce these contractions
During vaginal examination in labour, what else is assessed?
descent of the head
- this is assessed in relation to the ischial spines of the pelvis
- it is called the “station of the head”
- in early labour, the station is often -1
- the station becomes +1 during the second stage (below the ischial spines)
Other than by vaginal examination, how can descent of the head be assessed?
abdominal palpation
- it is described by how many 5ths of the baby’s head can be felt above the pelvis
When describing descent of the head, what is meant by 5/5 and 0/5?
5/5th palpable:
- all of the head is above the pubic bone
- all 5 fifths can be palpated
0/5th palpable:
- all of the head is below the pubic brim and cannot be palpated
- once the cervix is 10cm dilated, usually none of the head is felt
What are women encouraged to do during the first stage of labour?
- walk and remain in an upright position
- this has been seen to reduce the duration of labour, need for C-section and epidural
How can the second stage of labour be divided into 2 stages?
passive stage:
- the cervix is fully dilated to 10cm
- there is an absence of contractions
active stage:
- there are expulsive contractions / active maternal effort alongside full dilation of the cervix
Why does the passive stage of the second stage of labour occur?
- once the cervix is dilated to 10cm, the head moves down the pelvis and applies pressure to the pelvic floor
- pressure on the pelvic floor produces the urge to push
- it can take time for this urge to occur when the head is still high
What are the 2 approaches to the third stage of labour?
- physiological management
- active management
What is meant by physiological management in the third stage of labour?
- the placenta is delivered via maternal effort alone
- uterotonic drugs are not used
- there is no cord traction
What is meant by active management of the third stage?
- there is assistance in delivery of the placenta
- IM oxytocin is given to encourage the uterus to contract
- traction is applied to the umbilical cord to guide the placenta out
Who is offered active management of the third stage and why?
- it is offered to all women routinely to reduce the risk of postpartum haemorrhage
- it will be initiated if there is haemorrhage
OR
- a > 60 min delay in delivery of the placenta
