Labour Flashcards
What foetal hormones are released at parturition?
Prostaglandins, oxytocin and adrenal hormones (all control the timings of labour)
Prostaglandins will stimulate more vigorous muscle contractions
What mechanical changes help to bring about labour?
Increased muscle stretch will increase muscle contractility
Dilation of the cervix will also stimulate muscle contractions
What are the stages of labour?
1 - cervical dilation (8-24 hrs)
2 - passage of foetus through the birth canal (mins to 120mins)
3 - expulsion of placenta
Do eostrogen and prgesterone increase milk production?
No - they actually inhibit milk production
There will be a sudden decrease in E and P after birth.
What is the ‘milk let down reflex’?
also called the suckling stimulus - will promote the release of oxytocin from the post. pituitary gland to cause smooth muscle contraction within the breast and ejection of milk.
What are Braxton-Hicks contractions?
These are ‘practice contractions’ caused by the contraction of the uterine muscles. These differ from labour contractions as they are shorter, less painful and can be relived by changing activity level, position or taking sips of water.
What is Bishop’s score?
Score of the cervical readiness for labour and the foetal station: Dilation Effacement Consistency Position Foetal station
What is meant by ‘foetal station’?
The distance the foetal head is from the ischial spines:
- 3 cm is above the ischial spines
0 cm is at the ischial spines
+2cm is past the ischial spines
What is meant by cervical effacement?
How thin the cervix is - by 2nd stage of labour the cervix should be >80% effaced
What is meant by the cervical position?
How the cervix is orientated - in the first stage of labour it will move from the posterior to the anterior position
What occurs in the 1st stage of labour?
This is the movement of the foetus to the level of the ischial spines associated with cervical dilation/effacement/other changes.
What is the latent stage of stage 1 labour?
This is characterised by 3-4cm dilation and irregular contractions
Can last for a few days
What is the active stage of stage 1 labour?
Characterised by >4cm dilation and regular contractions (should be monitored every 30mins)
How much should the cervix dilate during active stage of stage 1 labour last in a nulliparous and multiparous woman?
N = 1cm/hr MP = 2cm/hr
What is stage 2 labour?
the progression from complete dilation to birth
How long should stage 2 labour take in nulliparous and multiparous women?
NP = 2 hrs (3 hrs with analgesia) MP = 1 hr (2 hrs with analgesia)
What is stage 3 labour?
The expulsion of the placental products - should take 5-10 mins if actively managed.
How is stage 3 labour managed actively?
With syntometrine infusion (oxytocin) - this will decrease blood loss after delivery
if >60 mins then indication to operate.
What is the pueperium?
This is the period of time after delivery where the tissues become normal again (usually about 6 weeks)
What is lochia?
This is vaginal discharge that is present after birth what contains blood, mucous and uterine tissue - it may be present for 2 weeks
What happens to CV system in the pueperium?
Returns to normal within 2 weeks
How fast will the vagina return to normal?
Will usually return to normal tone very quickly (within a week) but may be fragile for 1-2 weeks post-partum
How will the uterus be after birth?
It will be the size of a 20 week gestation baby but will decrease in 1 finger breath per day - day 12 should be non-palpable
What are some contraindications to induction of labour?
Malpresentation foetal distress vasa praevia placenta praevia tumour
When should IOL be considered?
If bishops score >7 but no active labour
How can IOL be carried out?
Manual amniotomy (rupture of membranes)
PEG2 (gel or pessary)
Oxytocin (to induce uterine contractions)
What are the options for analgesia in labour?
Non-pharma = massage, water bath, TENs machine Pharma = entenox, paracetamol/NSAIDs, IM opiods, Epidural, spinal, epidural+spinal
What are the considerations in an IM opiod?
It can cause a sleep like pattern on the CTG - reducing foetal HR, and flattening variation
What is an epidural?
Opiods are injected into the epidural space
- midwife administered
- patient admin
- continuous
What is a spinal?
This is when LA or opiods are injected into the sub-arachnoid space
What is the benefit to an epidural/spinal combo?
Can top up the spinal with epidural infusion
How is labour assessed?
Partogram and CTG
What is a CTG?
Cardiotocogram = assesses the foetal HR and contractions
What is a partogram?
This is a sheet that compiles all relevant information about the labour e.g. contractions (frequency and strength), cervical dilation, foetal station, FHR, duration of labour, signs of obstruction, amniotic fluid
What are some signs of obstruction that can be recorder?
Caput, moulding, vulval oedema, anuria, haematuria
What are the 3P’s in failure to progress?
Passage
Passenger
Power
Describe the 3 Ps in failure to progress
Passage - short stature, trauma, shape
Passenger - big baby, malpresentation
Power - inadequate frequency or strength
How should a foetus be assessed in stage 1 labour?
With doppler USS to monitor FHR - during and after each contraction (every 15 mins)
How should a foetus be assessed in stage 2 labour?
With doppler USS to monitor FHR during and after each contraction for at least 1 minute ( every 5 mins)
should also monitor maternal HR every 15 mins
What is the acronym used when interpreting a CTG?
DR C BRaVADO - determine risk, contractions, baseline, rate, variability, accelerations, decelerations, overall impression
What should you do if the foetus shows signs of distress during labour?
Reposition the mother, give IV fluid, stop syntocinon, give scalp stimulation, monitor foetal blood, monitor mothers vitals and consider tocolysis.
if appropriate then c-section
What is tocolysis?
The use of medication to suppress labour
When monitoring foetal blood what is normal and abnormal?
pH = 7.25 (normal) pH = 7.2-7.25 (borderline - repeat in 30 mins) pH = < 7.2 (abnormal - DELIVER)
What are assisted methods of labour?
Ventouse, forceps and c-section
Explain Ventouse delivery
suction cup applied to foetal head and allows midwife to assist in pushing (pull with the contraction)
has increased failure rates, can cause a cephalohaematoma, and retinal haemorrhage but reduces vaginal trauma, perineal pain and need for anaesthetic
Does ventouse delivery affect outcomes?
No - shows no change in long term outcomes
Explain a forceps delivery
metal tools applied to foetal head to aid in extraction of the foetus. There is a lower failure rate than ventous but increased vaginal tear and trauma.
What is an injury that can be caused by forcep delivery?
Vaginal tear and facial nerve palsy of the foetus
When should a c-section be considered?
Previous CS, foetal distress, failure to progress, breech position, maternal request
What are the risks associated with c-section?
Can increase maternal mortality x 4
there is also all the risks of surgery involved e.g. infection, blood loss, trauma, VTE
There are further risks of reduced fertility and complications in future pregnancies
What is aortocaval compression?
This occurs when the gravid uterus compresses the IVC and aorta and in turn will reduce venous return when in the supine position. This causes supine hypotension.
How is supine hypotension resolved?
Move the patient into a lateral position
During CPR how much of the CO is achieved in a non-pregnant and pregnant individual?
Non-preg = 30% preg = 10% due to aortocaval compression
During resus of a pregnant individual how long should you attempt CPR for?
4 minutes - if no signs of response then deliver baby to aid maternal resuscitation
What is meconium?
This is a dark green, bile heavy substance - baby’s first poo
What is the significance of meconium in the amniotic fluid?
Technically a sign of foetal distress. Check CTG:
- normal = monitor, reassure and continue with delivery
- abnormal = emergency CS as may have aspirated
What can be done to prevent tears and damage to the anus?
Episiotomy
When should the umbillical cord be clamped?
after 3 mins - clamping straight away can dramatically reduce the amount of RBC the baby receives
What are the hormone changes that initiates labour?
Progesterone drop (reduction in relaxation effect) oestrogen increase (increase contractibility) oxytocin release in response to neurostimuli
