Mechanisms of Labour Management of Normal Childbirth Flashcards
What is a midwife?
An expert in normal birth
What is the role of a midwife?
First point of contact during pregnancy and postpartum and early postnatal period
An independent practitioner
Care for women during labour
Recognise deviations from normal and refer to other health professionals
Still involved in the care of high risk women
When are women risk assessed and why?
In early pregnancy
To determine the appropriate level of care
Who will be the lead healthcare professional looking after a pt if they are deemed to be low risk?
The midwife
Who will be the lead healthcare professional looking after a pt if they are deemed to be high risk?
An obstetrician
Why are the theories of increasing rates of C-section increasing?
Increasing obesity leading to higher rates of gestational diabetes
Increased maternal age
Increased rates of oxytocin induction
Increased use of epidural anaesthesia
Risk averse culture - c-section deemed lowest risk in some cases
Define normal birth
Spontaneous in onset, low-risk at the start of labour and remaining so throughout labour and delivery. The infant is born spontaneously in the vertex position between 37 and 42 completed weeks of pregnancy. After birth, mother and infant are in good condition
What are the 4 stages of labour?
- latent stage
- first stage
- second stage
- third stage
What is the latent stage of labour?
- irregular, infrequent and sometimes mild contractions 2. 2. these allow the cervix to begin to efface and dilate from 0-4cm.
- Mucoid plug (‘show’)
What is the first stage of labour?
considered established labour
- the uterine contractions become stronger and more regular
- the cervix will become fully effaced, and dilate until 10cm.
At what rate does dilation occur in primiparous women?
0.5cm/hour.
What is fully dilated?
10cm
What is the second stage of labour?
From full dilation to the birth of the fetus
there is a passive hour before beginning pushing
How long can the second stage of labour last?
2-3 hours, but can be as little as 5 mins
How long does the latent phase of labour last?
2-3 days
What is the third stage of labour?
From the birth of the fetus to the expulsion of the placenta
Which hormones are involved in labour?
Prostaglandins Oxytocin Oestrogen Beta-endorphins Adrenaline Prolactin
What do prostaglandins do during labour?
Aid with cervical ripening - cervix becomes soft, the cervix will not become effaced until it becomes ripe
What does oxytocin do during labour and when is it produced?
Oxytocin surge at the beginning of labour (ie first stage)
Causes contractions of the uterus
What does oestrogen do during labour and when it is produced?
Oestrogen surge at the beginning of labour (ie first stage)
inhibits progesterone to prepare the smooth muscles for labour
What do Beta-endorphins do during labour?
Natural pain relief
What does Adrenaline do during labour and when is it released?
released as birth is imminent
gives the woman the energy to give birth
What does prolactin do during labour?
milk production in the mammary glands
What is synthetic oxytocin used for?
Induction of labour
What is the most advantageous position for labour?
Left occipito-anterior
As the occiput is presenting
What is the most position in labour?
Cephalic presentation
What is the difference between presentation and lie?
Presentation is the part of the baby that is presenting
Lie - is the vertical position of the baby in relation to the vertical position of the mother
What proportion of babies will be breech
3%
What types of lie are there?
Longitudinal lie - (so the presentation would be cephalic or breech)
Transverse lie
Unstable lie (keeps changing)
What types of presentation are there?
Cephalic (types of cephalic: OA, OP (and left and right variations), brow, face)
Breech - means bottom first- (types of breech: complete (both legs flexed), frank (both legs extended), incomplete (one leg flexed and one extended, footling)
What mode of delivery is common for breech presentation?
C section, though some can have a vaginal delivery
What mode of delivery is needed for transverse lie?
C section - vaginal birth not possible in this position
What do irregular contractions mean?
Vary in length and strength
What does skin to skin contact after labour do for the mother and baby?
releases oxytocin
Causes uterus to contract
Baby’s heart rate to regulate
Increases bond between baby and mother
In which part of the uterus do contractions start?
Fundus of the uterus - this is the pacemaker
In what direction does the uterus contract?
the lower segment of the uterus is pulled towards the fundus to open the cervix
What two factors help to dilate the cervix?
Contractions of the uterus
Pressure of the baby’s head on the cervix
What is cervical effacement?
The process of the cervix from being a closed tube that is 4cm thick to a thin layer
Therefore it is a thinning of the cervix
What is the mucoid plug?
A plug of mucus that protects the cervix during pregnancy
What is the difference between effacement and dilatation in nulliparous women compared to multiparous women?
In nulliparous women - effacement has to happen before dilatation
In multiparous women effacement occurs at the same time as dilatation
What is dilatation and how is it measured?
The diameter of the opening of the cervix.
By vaginal examination
What are the different types of pelvis?
Gynaecoid
Platypelloid
Android
Anthropoid
Which is the most common pelvis type and the one which is most favourable for vaginal delivery?
Gynaecoid
What are the advantages of the Gynaecoid pelvis?
- The inlet is slightly transverse oval
- Wide sacrum with average concavity and inclination
- Wide suprapubic arch
- Side walls are straight with blunt ischial spines
What is the android pelvis?
Heart shaped
Narrow suprapubic arch
Wider sacrum
Not good for childbirth
What is the platypelloid pelvis?
Transverse oval - baby gets stuck, transverse arrest
Not good for childbirth
What is the anthropoid pelvis?
Vertical oval
Narrow suprapubic arch and narrow sacrum
Ok for childbirth
What are the three bones of the foetal skull?
- Frontal
- temporal
- parietal
What is the main advantage of not having a fully formed skull during childbirth?
Allows for movement and overlapping during childbirth
How do you assess head engagement in labour?
- Abdominal examination
2. Vaginal examination (only done in labour)
What terminology would you use when assessing head engagement?
By abdominal examination
- 5 fifths - head not engaged
- 4 fifths - engaging…
- 3 fifths
- 2 fifths
- 1 fifth
- 0 fifths - head engaged
By Vaginal examination
- Minus 2 stations - not engaged
- Minus 1 stations - not engaged
- Zero station - engaged
- Plus 1 station - progressing
- Plus 2 stations
- Crowning
At what heag engagement would you deliver?
Plus 1 and plus 2 stations
Name the fontanelles of the skull
Anterior and posterior
Name the sutures of the skull
From back to front:
- Lamboid
- Sagital
- Coronal
What are the steps the fetus goes through during delivery?
- descent
- flexion
- internal rotation
- Extension
- Restitution
- External rotation
- Delivery of body
Describe what descent is
the presenting part of the fetus descends into the pelvis
What are the factors that assist in descent?
Increased abdominal muscle tone
Increased frequency and strength of contractions
Describe what flexion is
Flexion of the fetal neck to reduce the diameter of the head passing through the pelvis
Flexion of the neck happens by uterine contractions pressing on the fetal spine towards the occiput, causing
the occiput to come into contact with the pelvic floor.
Describe what internal rotation is
90 degree turn of the fetal head
What are the processes that aid flexion and internal rotation?
- Uterine contractions
2. Pressure of occiput onto pelvic floor
Describe what extension is
The fetal occiput will slip beneath the suprapubic arch allowing the head to extend
The fetal head is born (saying hello to the world).
If the occiput is anterior, the baby will be facing the mother’s back.
If the occiput is posterior, the baby will be facing the mother’s front.
What is restitution and external rotation?
The fetal head naturally aligns with the shoulders
This means that the fetal head externally rotates to face the left or right thigh of the mother
How is the body delivered?
Gentle downward traction of the head along the axis of the spine by the midwife to deliver the anterior shoulder
Gentle upward traction of the head along the axis of the spine by the midwife to deliver the posterior shoulder
When can spontaneous rupture of membranes occur (SROM)?
Before or during labour
- miscarriage - <20 weeks
- prelabour rupture of membranes - 20 weeks to labour
- rupture of membranes in labour
When can artificial rupture of membranes be used (ARM)?
When you want to induce labour
What are the functions of the amniotic fluid
Cushioning
Gives baby space to move
Full of stem cells for baby to ingest
What creates urine and meconium?
Swallowing amniotic fluid
How much amniotic fluid is normal at term?
500mls-800mls
What is delayed cord clamping and when is it used?
The umbilical cord is clamped after 1 minute to allow more blood to transfuse to the baby
Used in pre-term babies
What are the benefits of associated benefits?
- Allows the baby time to transition to extra-uterine life
- Increase in red blood cells, iron and stem cells (this can aid with growth and development up to 6 months old)
- Reduced need for inotropic support
Where is the placenta attached?
Uterine wall
What vessels are in the umbilical cord?
2 umbilical arteries
1 umbilical vein
What is the function of the placenta and cord?
Passage of oxygen and nutrients and maternal antibodies to the fetus and removal of wast products eg CO2 to the maternal bloodstream for disposal
The placenta produces hormones that assist with fetal growth and development.
Can alcohol and nicotine pass to the fetus through the placenta?
Yes
What are the two layers of the placenta?
Amnion - amniotic sac around the baby
Chorion - membrane around the placenta
What is the complication of leaving the placenta or part of the placenta in the uterus after delivery?
Postpartum haemorrhage
What drug can be given to assist in the delivery of the placenta?
IM Syntometrine (oxytocin + ergometrin)
When would you not give IM Syntometrin?
Pre-ecampsia or hypertension
Would give oxytocin on its on (Syntocinon)
If the mother doesn’t want it
How is pain managed in delivery?
Encourage long outbreaths Water birth Aromatherapy Massage Hypnobirthing TENS machine
Etonox - Gas and air (NO2) Paracetamol Codeine Opioids (diamorphine, pethidine, Remifentanyl) Epidural -
What are the alternative options for delivery?
Pool/water birth
Upright birth
What are the advantages of a water birth?
Calmness
Pain relief
Hands off approach
What are the advantages of upright brith?
Increases the diameter of the pelvic inlet
Less risk of compressing mothers aorta
Encourages stronger and longer contractions
Gravity
What are the disadvantages of using opioids?
If given too close to the birth of the child, then can cause respiratory depression and the baby may need respiratory support when born
What is epidural anaesthesia comprised of?
bupivacaine and fentanyl
How is medication administered in an epidural?
Via and epidural catheter and pump
How much pain relief does epidural provide?
Total pain relief in 90% and lasts until baby is born
What are the disadvantages of epidural?
Reduced mobility
Can take up to an hour to take effect
Will need a urinary catheter
Can slow down labour if not established
When is an epidural used?
Pain relief in vaginal labour
Or when C-section needs to start after an epidural has already been given as medication can be topped up by the catheter and pump
When is spinal used?
In C section (planned)
