Labour Flashcards
Define labour. (2)
The process whereby the fetus and placenta are expelled from the uterus, which normally occurs during weeks 37-42.
How is labour diagnosed? (2)
Painful uterine contractions are accompanied by dilatation and effacement of the cervix
What are the three stages of labour. (3)
1: Initiation to full cervical dilatation
2: Full cervical dilatation to delivery of the fetus
3: Delivery of fetus to delivery of placenta
What are the three mechanical factors that determine progress through labour? (3)
Power
Passage- dimensions of pelvis and resistance of soft tissues
Passenger- dimensions of fetal head
What bony prominences are used to measure the degree of fetal decent? (1)
Ischial spines
What is the ideal presentation of the fetus at birth? (1)
Flexed vertex presentation
extension of various degrees causes increased presenting diameter
How does the fetus rotate during the second stage of labour? (6)
Engagement in occipito-transverse (OT) Descent and flexion Rotation 90' to OA Descent Extension to deliver Restitution and delivery of shoulders
(in 5% it rotates to occipital-posterior and increased difficulty of delivery)
With regards to describing the fetal head, what does presentation and presenting part mean? (2)
Presentation: part of fetus that occupies the lower segment or pelvis.
Presenting part: lowest part of the fetus palpable on vaginal examination. e.g. vertex, brow, face.
What does the position and attitude of the head describe/ (2)
Position: describes the rotation. OT, OA or OP
Attitude: describes the degree of flexion.
What is effacement of the cervix? (2)
Normally tubular cervix is pulled up into the lower segment until it is flat. Commonly associated with bloody show.
Name the 2 phases of the first stage of labour. (2)
Latent (first 3 cm)
Active: 1cm/hour in nulliparous, 2cm/hour in multiparous
Define slow labour and prolonged labour. (2)
Slow labour: after latent phase, progress less than 1cm/hr
Prolonged labour: after latent phase >12 hours duration
Name 3 causes of slow progress in labour. (3)
Power: inefficient uterine action
Passenger: fetal size, disorder of rotation, disorder of flexion
Passage: cephalo-pelvic disproportion, rarely cervical resistance
How is slow progressing labour managed? (3)
Generally: can wait if desired, mobilise
Nulliparous: amniotomy, oxytocin
Multiparous: amniotomy, oxytocin if malpresentation excluded
If fails: C/S in first stage or instrumental delivery if second stage.
What is Bishop’s score? (1)
Pre-labour scoring tool to help determine whether induction of about will be required.
Name 2 methods of inducing labour. (2)
Vaginal PGE2.
Amniotomy (artificial rupture of membranes)
Oxytocin after SROM or ARM.
(Cervical sweeping of membranes)
Name 3 indications for induction of labour. (3)
Fetal: prolonged pregnancy, suspected IUGR or compromise, antepartum haemorrhage, Prelabour term rupture of membrane
Maternal: Pre-eclampsia, hypertension and diabetes
Name 2 absolute contraindications for inducing labour. (2)
Acute fetal compromise Abnormal lie Placenta praevia Pelvic obstruction After 2+ caesarean sections (increased risk of scar rupture)
Name 2 complications of induction of labour. (2)
Failure to start- inefficient uterine activity
Hyperstimulation of uterus- rare but can cause distress
Umbilical cord prolapse
Post partum haemorrhage
Intrapartum and postpartum infection
What is a PROM? (1)
What is PPROM? (1)
Premature rupture of membranes
Preterm Premature Rupture of Membranes
Name 1 risk of premature rupture of membranes. (1)
Cord prolapse
Neonatal infection
Felicity has had a premature rupture of membranes. How will you manage her? (2)
Vaginal swab (look for infection)
Avoid digital vaginal exam (unless risk of cord prolapse- abnormal lie or fetal distress)
CTG
Await SROM or induce labour
Name 2 indications for instrumental delivery. (2)
Prolonged active second stage
Fetal distress
Prophylactic to prevent pushing in patients with heart disease or hypertension
Breech delivery to control delivery of head
Name the 2 methods of caesarean sections. (2)
Lower segment caesarean section (LSCS)
Classical (vertical incision)
Define emergency caesarean section. (2)
Caesarean section performed in labour due to immediate threat to mother or fetus.
Give 2 complications of a caesarean section. (2)
Haemorrhage, uterine/wound sepsis, thromboembolism, anaesthetic problems, subsequent pregnancy delivery method complications.
Why should a pregnanct lady not lie completely supine? (1)
May cause aortocaval compression, decreasing cardiac output and causing hypotension.
Why should pregnant ladies lie on the left lateral position? (1)
Prevention of aortocaval compression.
If must lie supine, the table should be at 15’ left tilt.
What is recorded on a partogram? (2)
Records dilatation of the cervix with or without the descent of the head plotted over time.
It is also used to record maternal vital signs, fetal heart rate and colour of liquor.
Define fetal distress. (2)
Hypoxia that may result in fetal damage or death if not reversed or delivered urgently.
Name 2 methods that can determine fetal distress. (2)
- Meconium in liquor
- FHR every 15 mins in 1st stage and every 5 mins in the 2nd stage, using doppler or Pinards, or CTG.
- CTG: records fetal hr and contractions
- Fetal blood sampling: if pH<7.2 deliver by quickest method
What are the stages of assessing a Cardiotocogram? (5)
DR C BRAVADO
DR: define risk
C: contractions per 10 mins
BR: basline rate (110-160bpm)
V: variability (<5bpm) unless during fetal sleep that should last less than 45 mins
A: accelerations with movements and during contractions is encouraging
D: decelerations (early, variable or late)
O: overall assessment
Describe the 3 different types of decelerations. (3)
Early: synchronous with contraction as normal response to head compression
Variable: vary in timing and reflect cord compressions
Late: presist afetr contraction has completed and are suggestive of hypoxia
What is the management of fetal distress? (4)
1: intermittent auscultation of FHR: if abnormal or meconium or long/high risk labour then go to 2.
2: continuous CTG: if sustained bradycardia, deliver; for other abnormalities, try alleviate with simple measures then if fails go to 3.
3: fetal blood sample: if abnormal go to 4
4: deliver by quickest method
Name 2 simple methods that may alleviate CTG abnormalities. (2)
Oxygen Move to left lateral position IV fluids Stop oxytocin infusion if applicable Vaginal exam to check for cord prolapse.
Name 2 non-medical and 2 medical methods of anagesia in labour. (4)
Non-medical: TENS, antenatal classes, mobilising, back rubbing, water at body temperature
medical: Entonox (O2 and NO), Pethidine, Spinal anaesthetic, Epidural, Pudenal nerve block
Lucy has decided to have an epidural, what level will Dr Hoy inject? (1)
What layers will he have to inject through? (4)
L3/4 Skin Subcutaneous fat Supraspinous ligament Interspinous ligament Ligamentum flavum NOW IN EPIDURAL SPACE Dura mata Arachnoid mata NOW IN SPINAL ANAESTHETIC SPACE
name an advantage and a disadvantage of using an epidural in labour. (2)
Advantage: pain free, can lower bp in hyertensive patient
Disadvantage: regular bp and pulse monitoring, mother is bed bound, Can develop urinary retention due to loss of bladder sensation.
name 2 complications with epidural. (2)
Spinal tap (accidentally cause leakage of CSF from subarachnoid space and cause headache)
Total spinal anaesthetic (respiratory paralysis)
Hypotension
Increased rate of instrumental delivery
Urinary retention
What is active management of the third stage of labour? (2)
Give one benefit. (1)
IM oxytocin (Syntocin) or Syntometrine (with ergometrine) can be injected after shoulders of last fetus have been delivered to encourage uterine constriction. (NB ergometrine can cause vomiting and is contraindicated in hypertensive disease)
Decreases risk of post partum haemorrhage and thus less chance of transfusion.
Clinically, how can partial separation of the placenta be indicated? (1)
How should the placenta be removed? (1)
Elongation of the cord and passage of blood.
Gentle traction on the cord, while the left hand presses on the suprapubic region to prevent uterine inversion.
Define a retained placenta. (1)
Third stage of labour lasting over 30 minutes.
if there is no bleeding, it may be left for up to one hour to separate naturally.
