Normal labour Flashcards
What are the key hormones that cause labour to start?
prostaglandins
oxytocin
What hormonal changes take place towards the end of pregnancy?
Increased concentrations of oestrogen
stimulates production and release of prostaglandins
+
promotes formation of oxytocin receptors = myometrium more sensitive to oxytocin
Why are oxytocin and prostaglandins important in end-stage pregnancy/labour?
Strong myometrial stimulants
Play a major role in cervical ripening
What changes occur in the myometrium towards the end of a pregnancy?
Stretching increases muscle excitability and contractility
gap junctions are formed (under influence of oestrogen) - enables transmission of electrochemical signals from cell to cell and a synchronized contraction wave
What changes occur in the cervix towards the end of a pregnancy?
Decrease in collagen
Increase in water content
- allows cervix to soften, efface and dilate (ripen)
What is the definition of latent labour?
Period of time (not necessarily continuous):
Painful contractions
Some cervical change - effacement
dilation up to 4cm
What is recommended to women in latent labour?
Women usually cope well
Encouraged: stay hydrated, eat snacks, mobilise, rest, warm baths, massage, paracetamol analgesia
What are the features that indicate established labour?
Regular painful contractions
Progressive cervical dilation from 4 cm
What is recommended to women in established labour?
Continuous one-to-one care from a midwife
What are the different stages of (established) labour?
1st stage: Onset of established labour (4cm) to full dilation of the cervix (10cm)
2nd stage: from full dilation to birth of the baby
3rd stage: from birth of baby to expulsion of placenta and membranes
What is the first stage of labour?
Onset of established labour (4cm) to full dilation of the cervix (10cm)
What is the second stage of labour?
from full dilation to birth of the baby
What is the third stage of labour?
from birth of baby to expulsion of placenta and membranes
How is descent of the head measured?
How is this also known?
During vaginal examination
In relation to ischial spine of pelvis
AKA station of the head
What is a common station of the head in early labour?
-1
above the ischial spine
What is a common station of the head in second stage of labour?
+1
below the spines
Other than PV exam, how else can one check the descent of the head?
Abdominal palpation (how many 5ths of babies head can be felt above pelvis)
Head above pubic bone - 5/5ths palpable
once cervix 10cm dilated - none of head is felt, 0/5ths palpable
How can one help cervical dilation and descent of the head?
Mobilisation - walking and upright positions
How can mobilising during the first stage of labour help the progression of labour?
Reduces:
Duration of labour
Risk of caesarean birth
Need for epidural
How can the second stage of labour be divided further?
Passive
Active
What is the passive 2nd stage of labour?
Full dilation of cervix
Prior to or in absence of involuntary expulsive contractions
What is the active 2nd stage of labour?
Expulsive contractions or active maternal effort
Full dilation of cervix
Other than urge to push, what other signs of stage 2 labour?
Anal dilation and perineum bulging
How can you limit the risk of perineal damage during childbirth?
Anal pad - pressure on perineum
Ask mother to pause once head is out, as her to breath and give little pushes
What is delayed cord clamping, how and why is it done?
delayed cord clamping: waiting for at least a minute before cutting cord - wait for cord to stop pulsating
reduces risk of anaemia in babies
What are the two ways that the third stage of labour can be managed?
Active management
Physiological management
What is active management of the third stage of labour?
Use of uterotonic drugs (syntometrine)
Deferred clamping and cutting of cord (>1 min)
Controlled cord traction (apply counter-pressure, just above the pubic bone to guard the uterus and apply gentle downwards traction of the cord)
What are the benefits of active management of third stage of labour?
Reduced risk of postpartum haemorrhage
Shortens length of the third stage
What are the drawbacks of uterotonic drugs?
increase amount of nausea and vomiting
How would you physiologically manage a woman in the third stage of labour?
No routine use of uterotonic drugs
No clamping of cord until pulsation has ceased
Delivery of placenta by maternal effort
Where should a woman give birth?
Mother’s choice:
low risk women: midwifery unit is equally as safe as obstetric unit
Home birth safe for multis, but slightly higher risk in primips
What should women be advised re. food and drink during labour?
Drink throughout
Light meals when desired (unless having opiates or increasing chance of GA)
What should women be advised re. bladder careering labour?
Encourage women to pass urine regularly
May need catheter if unable to pass urine (eg. epidural)
What observations would you need to for someone in normal labour?
vital signs
urine analysis
vaginal loss - liquor (say colour), fresh blood
contractions
What would you watch for in a woman who’s membranes have ruptured?
Meconium or blood-staining liquor
Could indicate an antepartum haemorrhage
What are some non-pharmacological pain relief methods used in labour?
massage
relaxation and breathing
water
mobilisation
What are some pharmacological pain relief methods used in labour?
Paracetamol
Nitrous oxide (gas and air)
opiates (diamorphine)
epidural
What foetal monitoring is done in low-risk women?
intermittent auscultation of fatal heart using doppler US or pinard stethoscope
What foetal monitoring is done in high-risk women?
continuous fetal monitoring using a cardiotocograph (CTG)
