Normal Labour and Puerperium Flashcards
Define what labour is
A physiological process during which the fetus, membranes, umbilical cord & placenta are expelled from the uterus
What associated things occur during labour ?
- Regular, painful uterine contractions with increasing frequency, intensity and duration
- Biochemical changes in the cervical tissue allowing cervical effacement and cervical dilatation
What are the 3 key factors during labour ?
- POWER - Uterine Contraction
- PASSAGE - Maternal Pelvis – some are more suitable than others
- PASSENGER - Fetus
What are the 3 main hormones involved during labour?
- Progesterone
- Estrogen
- Oxytocin
What is the effect of progesterone during labour ?
It decreases uterine contractility by preventing gap junction formation and ==> hindering contracility of myocytes
What is the effect of estrogen during labour?
- It increases uterine contractility
- It also promotes prostaglandin production which further increases uterine contractility
What is the effect of oxytocin during labour ?
- It initiates and sustains uterine contractions (it acts on decidual tissue to promote prostaglandin release ==> increases uterine contractility)
The exact cause for the initation of labour is unclear, however list some of the potential factors which could cause it ?
- Change in the estrogen/progesterone ratio
- Fetal adrenals and pituitary hormones may control the timing
- Myometrial stretch (as uterus gets bigger) increases excitability of myometrial fibres
- Mechanical stretch of cervix and stripping of fetal membranes
- Fergusons Reflex = neuroendocrine reflex comprising the self-sustaining (positive feedback) cycle of uterine contractions initiated by pressure at the cervix or vaginal walls
- Pulmonary surfactant secreted into amniotic fluid
- Increase in production of fetal cortisol stimulates an increase in maternal estriol
- Increase in myometrial oxytocin receptors and their activation ==> increased uterine contractility
What is the bishops score used for ?
It is the best and simplest method used to assist in predicting whether or not induction of labour will be required/is safe
What are the 5 elements of the bishops score ?
- Cervix position - post, mid, or ant.
- Cervical consistency - firm, medium or soft
- Cervical effacement
- Cervical dilatation
- Station of body in pelvis
How many stages of labour are there ?
3 main stages
What is the 1st stage of labour divided up into ?
The latent and active phases
Define the latent stage of labour
- This is the start of labour up to 3-4cm dilated
- There is mild irregular contractions, cervix shortens and softens.
How long does the latent stage of labour last ?
This stage duration is variable and may take up to a few days
Define the active phase of labour
- This is from 4cm dilation until full dilation
- During this stage contractions are progressively more rhythmic and stronger and slow descent of the baby begins
State what normal progress is during the active phase and also what factors may affect this
- 1-2cm of increased dilatation per hour
- Analgesia, movement and parity all cause variability in this
Define the second stage of labour
Starts from full dilatation (10cm) to delivery of the baby
What is the normal duration of the second stage of labour?
- In nulliparous women it is considered prolonged if it exceeds 3hrs with regional anaesthesia or 2hrs without
- In multiparous women it is considered prolonged if it exceeds 2hrs with regional anaesthesia or 1hr without
Define what a nulliparous women is
A women who has never given birth before, also applies to women who have had stillbirths or a baby whom was not able to survive outside the womb
Define the 3rd stage of labour
Starts from time of delivery of the baby until expulsion of the placenta and fetal membranes
What is the normal duration of the 3rd stage of labour ?
Usually takes 10mins
What are the 2 options for management of the 3rd stage of labour ?
Active or expectant management
Describe what active management is
- This is where oxytocin or syntometerine (oxytocin + ergometerine) is administered following birth of the anterior shoulder or immediately after the birth of the baby
- Cord clamping and cutting after 1-5mins after birth
- Controlled cord traction - placenta pulled out once its separated from the uterus
- Bladder emptying
Note For active management, administer oxytocin by IM injection with the birth of the anterior shoulder or immediately after the birth of the baby and before the cord is clamped and cut. Use oxytocin as it is associated with fewer side effects than oxytocin plus ergometrine
Describe what expectant management of the 3rd stage of labour is
- spontaneous delivery of the placenta
- Cord is clamped and cut once its stopped pulsating
- You push placenta out with contractions - can take up to an hour
Which is the preferred option for the management of the 3rd stage of labour and why?
Active management - because it lowers the risk of post-partum haemorrhage (PPH)
When is the 3rd stage of labour considered prolonged and what is then done ?
After 1hr - preparation is then made for removal under GA