Labour Flashcards
What are the roles of the different hormones involved in the initiation of labour?
Progesterone inhibits contractions
Oestrogen stimulates contractions
(more oestrogen : progesterone for labour)
Oxytocin initiates and sustains contractions and acts on decidual tissues to promote prostaglandin release
What are the fetal contributions to the initiation of labour?
Fetal pulmonary surfactant - secreted into the amniotic fluid - stimulates prostaglandin synthesis
Fetal cortisol stimulates an increase in maternal oestrogen
Fetus causes stretch of the cervix (fergusons reflex)
Describe the cervical changes which occur in normal labour?
Cervical softening and ripening
What is Bishops score for?
To determine whether it is safe to induce labour
Score <5 = induction will be necessary, score >9= labour will likely occur spontaneously
What are the 5 things involved in Bishops score?
Position
Consistency
Effacement
Dilatation
Station in the pelvis
What happens in the first stage of labour?
Involves a latent and an active stage
latent stage: up to 4cm dilatation with mild irregular contractions
active stage: 4-10cm dilatation with slow descent of the presenting part, contractions are strong and rhythmic
What happens in the second stage of labour?
From 10cm dilated to expulsion of the baby
What happens in the third stage of labour?
Expulsion of the placenta and fatal membranes
What analgesia options are available for labour?
Entonox
Paracetamol/ co-codamol
Diamorphine
Epidural
Remifentanyl
TENS machine
What are the 7 cardinal movements in labour?
Engagement Descent Flexion Internal rotation Crowning and extension Restitution and external rotation Expulsion
When is the fetus considered to be ‘engaged’ in labour?
When the widest brim of the fetal head has entered the brim of the pelvis
3/5ths = engaged (2/5ths can be palpated abdominally)
What is crowning?
Appearance of the fatal head at the introitus
Why is delayed cord clamping important?
Involves good blood flow to vital organs following delivery
What volume is considered normal blood loss in labour?
<500mls
What is the puerperium?
The period of 6 weeks after birth when there is repair and recovery of tissues and return to a non-pregnant state
How long does blood stained discharge last following birth?
10-14 days
When should labour be induced after rupture of the membranes?
Labour should usually be induced within 48 hours due to the risk of infections
What is the normal frequency and duration of contractions in labour?
3-4 contractions in 10 minutes
Initially last 10 seconds and then increase up to about 45 seconds
How is cord prolapse managed?
Urgent C-section
What are some of the possible complications of using epidural anaesthesia for labour?
Hypotension
Dural puncture headache
What are some of the possible signs of obstruction in labour?
Moulding
Caput
Anuria/ haematuria
Vulval oedema
“DR BRAVADO” is a mnemonic used to help remember what to look for on a CTG. What does it stand for?
Dr = determine risk BRA = baseline heart rate V = variability A = accelerations D = decelerations O = overall
What is the normal baseline heart rate of a fetus?
110-150bpm
Fatal blood sampling can be done during labour to determine hypoxia. What is the normal pH value?
Scalp pH >7.25 is normal
<7.2 requires immediate delivery
