Normal labour and delivery Flashcards
What is the definition of the onset of labour?
the point when uterine contractions become regular and cervical effacement (thinning) and dilatation becomes progressive
What is labour?
the process by which the fetus is delivered after the 24th week of gestation
What is considered the duration of labour in clinical practice?
the duration of observed labour, no the duration the mother had painful contractions at home
How do show and rupture of membranes relate to labor?
they may or may not be associated with labour - in themselves, do not suggest onset of labour
What are 6 things that labour is characterised by in most cases?
- Onset of uterine contractions, which increase in frequency, duration, and strength over time.
- Cervical effacement and dilatation.
- Rupture of membranes with leakage of amniotic fluid.
- Descent of the presenting part through the birth canal.
- Birth of the baby.
- Delivery of the placenta and membranes.
What are 7 stages in the sequence for passage through the pelvic for a normal vertex delivery?
- Engagement and descent: the head enters the pelvic in the occipito-transverse position with increased flexion as it descends
- Internal rotation to occipitoanterior: occurs at level of ischial spines due to forward and downward sloping of levator ani muscles
- Crowning: head extends, distending the perineum until it is delivered
- Restitution: the head rotates so that the occiput is in line with the fetal spine
- External rotation: the shoulders rotate when they reach the levator muscles until the biacromial diameter is anteroposterior (head externally rotates by same amount)
- Delivery of anterior shoulder: occurs by lateral flexion of trunk posteriorly
- Delivery of posterior shoulder: occurs by lateral flexion of trunk anteriorly and rest of body follows
What is the definition of the first stage of labour?
onset of labour to full dilatation, divded into two phases: latent and active
What are the 2 phases that make up the first stage of labour?
- Latent phase: period taken for cervix to completely efface and dilate up to 4cm
- Active phase: regular painful contractions when the cervix dilates from 4cm to full dilatation (10cm)
What are Braxton-Hicks contractions?
Mild, often irregular, non-progressive contractions that may occur from 30 weeks gestation (more common after 36 weeks) and may often be confused with labour
How do Braxton-Hicks contractions compare with normal labour?
contractions in labour are painful, with a gradual increase in frequency, amplitude, and duration - Braxton Hicks are ore mild, irregular, non-progressive
When wouldn’t you clinically intervene with labour?
if progress is normal and there is no concern for the mother or the fetus
What are 2 things that should make you suspect failure to progress in the first stage of labour?
- There is <2cm dilatation in 4h (on a 4hr action line partogram the plotted progress falls to the right)
- Slowing in progress in parous women
What are the 2 terms given to type of dysfunction first stage of labour and what do they mean?
- Primary dysfunctional laboru: labour slow from onset
- Secondary arrest: if there was previous adequate progress
What are 4 causes of poor progress in the first stage of labour?
- Power: inefficient uterine activity
- Passenger: malpositions, malpresentation, or large baby
- Passage: inadequate pelvis
- Combination of two or more of the above
What are 5 parts of an assessment of poor progress in the first stage of labour?
- Review the history
- Abdominal palpation of, frequency, and duration of contractions
- Review fetal condition: fetal heart rate and colour/quantity of amniotic fluid
- Review maternal condition including hydration and analgesia
- Vaginal assessment: cervical effacement, dilatation, caput, moulding, position, and station of head
What are 4 options for management of poor progress in the first stage of labour?
- Amniotomy (i.e. artificial rupture of membranes [ARM]) and reassess in 2h
- Amniotomy + oxytocin infusion and reassess in 2h: this should always be considred in nulliparous women
- Lower segment CS (if there is fetal distress)
In which group of women with poor progress in the first stage of labour should amniotomy with oxytocin always be considered?
nulliparous women
When would you consider lower segment C-section in poor progression in the first stage of labour?
if there is fetal distress
What must be done before starting oxytocin in women with poor progression in the first stage of labour, who are multiparous and those with a previous CS?
experienced obstetrician should review before starting oxytocin
What are 6 vital parts of monitoring in labor?
- Fetal heart rate - every 15 minutes (or continuously with CTG)
- Assess contractions every 30 minutes
- Maternal pulse should be checked hourly
- BP and temperature should be checked 4 hourly
- VE should be offered every 4h to assess progress
- Maternal urine is tested 4-hourly or when passed for ketones and protein
How are all 6 vital parts of monitoring during labour recorded?
on the partogram - graphical representation of progress of labour
What is the definition of the second stage of labour?
time from full cervical dilatation until the baby is born
How long is usually allowed for passive descent of the baby before active pushing is commenced and what are the conditions of this?
1 hour - if woman has an epidural and the CTG is reassuring
In the hour between reaching full dilatation and beginning active pushing, what must be ensured?
good contractions are maintained and oxytocin may be commenced
Within what time frame from the start of the 2nd stage of labour must birth take place for 1. nulliparous women and 2. multiparous women?
- 3 hours
- 2 hours
When is the definition of the start of the active second stage of labour?
commences when mother starts expulsive efforts using her abdominal muscles with the Valsalva manoeuvre to ‘bear down’
What are 4 positions which women may choose to deliver?
- squatting
- standing
- on all fours
- supine
- lithotomy position, if instrumental - supine with legs flexed at 90 degrees
What are 3 steps to the normal second stage of labour?
- As head comes down, it distends perineum and anus - can use pad to support perineum and cover anuswhile other hand used to maintain flexion and prevent sudden deflexion and control rate of delivery of head
- With next contraction, gentle traction guides head towards perineum until anterior shoulder is delivered under suprapubic arch
- Cord double-clamped and cut
What is the purpose of using a pad to support the perineum and cover anus while using other hand to maintain flexion and prevent sudden deflexion during the second stage of labour?
control rate of delivery of head - attempts to slow perineal distension, minimising tears by preventing rapid delivery
Why might an episiotomy be performed in the second stage of labour?
if there is concern that the perineum is tearing towards the anal sphincter (shouldn’t be used routinely)
Why should you slightly delay cutting the umbilical cord following delivery of the baby?
delaying for 2-3 mins results in higher haematocrit levels in the neonate - allows physiological transfer of placental blood to infant
At what points following birth of the baby is it assessed and using what system?
1, 5, and 10 minutes
Apgar scoring system
(if all well, hand baby back to mother as soon as possible)
What is considered a delay in the second stage of labour in 1. nulliparous women and 2. multiparous women?
- Nulliparous: if delivery not imminent after 1 hour of active pushing
- Multiparous: if delivery not imminent after 1 hour of active pushing (i.e. same for both)
What should be done if there is a delay in the second stage of labour in nulliparous women (>1hr of active pushing)?
offer vaginal examination and amniotomy recommended
if not delivered in 2 hours: requires review by obstetrician to consider instrumental delivery or C-section
What should be done if there is a delay in the second stage of labour in multiparous women (>1hr of active pushing)?
requires review by obstetrician to consider instrumental delivery or CS (sooner than in nulliparous women)
What should you be suspicious of in a delay in the second stage of labour in a multiparous woman?
malposition or disproportion
What are 2 ways to manage the third stage of labour?
- Active management
- Physiological management
What is the definition of the third stage of labour?
the duration from delivery of the baby to delivery of the placenta and membranes
What 3 things does active management of the third stage of labour involve?
- Use of uterotonics (oxytocin, ergometrine, misoprostol)
- Clamping and cutting of the cord
- Controlled cord traction
What are 4 examples of uterotonic drugs?
- Ergometrine
- Ergometrin + oxytocin - Syntometrine
- Oxytocin
- Misoprostol (prostaglandin analogue)
What is meant by controlled cord traction in active management of the third stage of labour?
traction applied to the umbilical cord once the uterus has contracted after the birth of the baby, and placenta felt to have separated from the uterine wall, whilst counter pressure applied to uterus until placenta delivers
What are 4 benefits to an active as opposed to physiological management of the third stage of labour?
- Reduced rates of postpartum haemorrhage over 1L
- Reduced mean blood loss and postnatal anaemia
- Reduced length of the third stage
- Reduced need for blood transfusions
What are 2 adverse effects of active management of the third stage of labour?
- Nausea and vomiting
- Headache
What is physiological management of the third stage of labour? 5 aspects
- no syntometrine or oxytocin given (uterotonics)
- cord allowed to stop pulsating before clamped and cut - clamp for at least 1 minute, unless baby’s heart rate is <60bpm and not picking up
- Cord should be clamped before end of 5 minutes
- Placenta delivered by maternal effort alone
- Cord not pullsed, uterus not push on to help expel placenta
What are 3 things that mean a planned physiological 3rd stage of labour should be changed to active management?
- Haemorrhage
- Failure to deliver the placenta within 1h
- Maternal desire to shorten the 3rd stage
What are 5 steps to an actively managed third stage of labour?
- Syntometrine IM (ergometrine 0.5mg + oxytocin 5I) or oxytocin 10IU IM given as anterior shoulder of baby born
- Dish placed at introitus to collect placenta and any blood loss, and left hand is placed on the abdomen over the uterine fundus
- As uterus contracts to 20 week size, the placenta separates from the uterus through the spongy layer of the decidua basaline
- Uterus will then feel globular and firmer, cord will lengthen, there is often trickle of fresh blood (separation bleeding)
- Controlled cord traction (CCT) applied with right hand, whilst supporting fundus with left hand (Brandt-Anrew’s technique)
What is syntometrine?
ergometrine 0.5mg + oxytocin 5IU
What must be excluded before uterotonics are given in the third stage of labour?
multiple pregnancy (twins etc.)