Labour Flashcards
what are the 3 key factors during labour
POWER: Uterine Contraction
PASSAGE: Maternal Pelvis
PASSENGER: Fetus
what hormone initiates and sustains contractions
oxytocin
what other roles does oxytocin have
acts on decidual tissue to promote prostaglandin release
what hormone makes the uterus contract
oestrogen
what is the other function of oestrogen in labour
promotes prostaglandin production
what its the role of progesterone
This keeps the uterus settled.
It prevents the formation of gap junctions
Hinders the contractibility of myocytes
what hormone changes cause the initiation of labour
progesterone withdrawal
increase in oestrogen and prostaglandin action
what hormone from the placenta is likely involved in starting the changes leading to labour
corticotrophin-releasing hormone (CRH)
there are 3 stages of labour - what is involved in stage 1
Commences with onset of regular painful contractions - split into latent and active phase
- Latent phase = 3-4cms dilatation
- Active phase = 4cms -10cms (full dilatation)
there are 3 stages of labour - what is involved in stage 2
Full dilatation achieved
Delivery of baby
Divided into pelvic/passive phase [head descends down pelvis] and active phase [when the mother pushes]
there are 3 stages of labour - what is involved in stage 3
expulsion of placenta and membranes after birth of baby
after what time is the decision made to go and remove the placenta under GA
1 hour
what can be given to help the mother deliver the placenta
oxytocic drugs
- oxytocin 10 units
- Syntometerine
controlled cord traction
what changes in the cervix happen for labour
Cervical softening and ripening
what are Braxton Hicks contractions
Tightening of the uterine muscles, thought to aid the body prepare for birth
Can start 6 weeks into pregnancy but not usually felt until second or third trimester
what are true labour contractions
pain described as a wave
- starts low, rises until it peaks, and finally ebbs away
how will the mothers abdomen feel during contraction
hard
where about do the contractions start in the uterus
the fundus
what are Braxton Hicks Contractions also called
False labour
what are features of a Braxton Hicks Contractions that can help you differentiate from true contractions
irregular
do not increase in frequency or intensity
resolve eventually
relatively painless
what cause real labour contractions
oxytocin
what are features of real labour contractions
evenly spared
time between them gets shorter
get more intense and painful
promotes thinning of the cervix
don’t resolve
what is the ostia
distal tube opening of the infundibulum of uterine tube into the abdominal cavity
where do the contractions synchronise from
both ostia
what shape of pelvis is the most suitable female pelvis shape
Gynaecoid pelvis
what are the other shapes of pelvis called
Anthropoid Pelvis
Android Pelvis.
Platypelloid Pelvis
what is the function of liquor
nurtures and protects fetus and facilitates movement
what colour should the liquor be
clear
- red/pink suggests bleeding
what is the normal fetal presentation
Longitudinal Lie
Cephalic Presentation
Presenting part = vertex
hence, what is called normal position in labour
occipitoanterior
with head engaging occipital-transverse
what are the major fontanelles in the fetal skull
anterior fontanelle [diamond shaped]
posterior fontanelle
how do the head’s of the foetus in 95% of vertex presentation appear
flexed
what position does a flexed vertex baby go into
NORMAL
i.e. occipitoanterior
what position does an extended or deflexed vertex baby go into
occipitoposterior OR transverse
how is the decent of the head referenced
abdominal fifths
what is crowning
Appearance of a large segment of fetal head at the introitus
Labia are stretched to full capacity
what may be required, to prevent trauma to the anal sphincters due to crowing
episiotomy
what is the bishop score used for
to determine if it is safe to induce labour
what are the 5 elements of the Bishops score
Position Consistency Effacement Dilatation Station in Pelvis
what are analgesic options for labour
Paracetamol/ Co-codamol TENS [electrical pulses] Entonox [inhalation agents] Diamorphine Epidural IV Remifentanyl Combined spinal/epidural
why do mothers on epidurals need to be monitored
as it can cause resp depression
what is a normal amount of blood loss in labour
< 500mls
what is a abnormal amount of blood loss in labour
> 500 mls
what is a significant amount of blood loss in labour
> 1500 mls
what are the signs that indicate placental separation
Uterus contracts, hardens and rises
Umbilical cord lengthens permanently
Gush of blood variable in amount
how is haemostasis achieved after delivery
Tonic contraction of uterine muscle strangulates blood vessels
Thrombosis of the torn vessel ends: pregnancy is a hyper-coaguable state
what is puerperium
6 week period after delivery as tissues return to non-pregnant state
in the puerperium period, there can be a lot of discharge, what are the different types?
Lochia: Vaginal discharge containing blood, mucus and endometrial castings
Rubra (fresh red)
Serosa (brownish-red, watery)
Alba (yellow)
what induces lactation
placental expulsion
what is Colostrum
name given to milk produced by mothers
what is Colostrum rich in
immunoglobulin
what is in an epidural anaesthesia
Levobupivacaine +/- Opiate
why is epidural anaesthetic useful
Does not impair uterine activity
[May inhibit progress during stage 2[
what are complications of epidural anaesthetic
Hypotension Dural puncture Headache Back pain Atonic bladder
how can progress be assessed in labour
Cervical dilatation
Descent of presenting part
Signs of obstruction
when should you suspect delay in stage
If Nulliparous <2cm dilation in 4 hours
Parous <2cm dilation in 4 hours or slowing in progress
what should you think about when considering a cause for failure to progress
3 P’s
Power
Passage
Passenger
what dysfunction in power could lead to failure to progress
Inadequate contractions: frequency and/or strength
what dysfunction in passages could lead to failure to progress
Short stature / Trauma / Shape
what dysfunction in passenger could lead to failure to progress
Big baby
Malposition - relative cephalo-pelvic disproportion
what is commenced as part of assessing progress as soon as a women enters the labour ward
the partogram
what tools are used to assess fetal well being
Doppler auscultation of fetal heart
Cardiotocograph (CTG) (+/- STAN)
Colour of amniotic fluid
when is doppler auscultation of the fetal done
Stage 1:
During and after a contraction
Every 15 minutes
Stage 2:
Every 5-10 minutes
what are risk factors for fetal hypoxia
Small fetus Preterm / Post Dates Antepartum haemorrhage Hypertension / Pre-eclampsia Diabetes Epidural analgesia Induction / Augmentation of labour
if a baby has any risk factors for fetal hypoxia what is done
continous monitoring of the fetal heart
what are acute cause of fetal distress
Abruption Vasa Praevia Cord Prolapse Uterine Rupture Feto-maternal Haemorrhage Uterine Hyperstimulation Regional Anaesthesia
what are subacute cause of fetal distress
hypoxia
what does a CTG monitor/record
contractions decelerations accelerations variability baseline HR
what is the normal baseline HR
110-150 bpm
tachycardia > 150
bradycardia < 110
what is the normal variability in fetal HR
5-25 bpm
how is CTG results classified
normal
non-reassuring
abnormal
Mx of fetal distress
Change maternal position
IV Fluids
Stop syntocinon
Consider tocolysis - Terbutaline 250 micrograms s/c
Maternal assessment - Pulse / BP / Abdomen / VE
Fetal blood sampling
Operative Delivery
fetal blood sampling shows scalp pH = what result would be normal, baseline and abnormal
pH >7.25 = normal
7.20 - 7.25 = borderline
< 7.20 = abnormal
what action would a borderline fetal blood sampling require
repeat in 30 mins
what action would an abnormal fetal blood sampling require
deliver the baby
what length of duration is ok in a women that has never given birth before for stage 2 of labour
no epidural < 2 hrs
epidural < 3 hrs
what length of duration is ok in a women that has given birth before for stage 2 of labour
no epidural < 1 hrs
epidural < 2 hrs
what is Ventouse
vacuum-assisted vaginal delivery or vacuum extraction (VE)
what is ventouse associated with
increased failure
increased cephalohaematoma
increased retinal haemorrhage
increased maternal worry
decreased anaesthesia
decreased vaginal trauma
decreased perineal pain
what are indications of C-section
previous CS fetal distress failure to progress in labour breech presentation maternal request
C-sections are associated with 4x greater mortality - what leads to morbidity
sepsis, haemorrhage, VTE, trauma, TTN, subfertility, complications in future pregnancy
what are indications for inductions of labour
Maternal = Pre-eclampsia, Poor obstetric history
Fetal = Suspected IUGR, Rhesus isoimmunisation, Antepartum Haemorrhage
Both= Post Dates Pregnancy, DM, Obstetric Cholestasis
what are methods for induction
Prostaglandins - PGE2 Dinoprostone (Prostin gel / Propess pessary)
Mechanical - Membrane sweep, Foley Balloon Catheter
Amniotomy
IV Syntocinon [synthetic oxycontin]
