Labour Flashcards
What are the 3 stages of labour
1st stage – initiation so full cervical dilation
2nd stage – full dilation to foetal delivery
3rd stage – foetal delivery to delivery of placenta
what forces determine progress during labour
Power - degree of expulsion of the foetus
passage - dimensions of pelvis + soft tissue resistance
passenger - diamters of the foetal head
what is associated with poor uterine contraction during labour
nulliparity
induction of labour
why are the ischial spines an important landmark in labour
used to determine the level of descent or ‘station’ of the head of the baby
station 0 = level of spines
-2 = 2cm above
+2 = 2 cm below
what is the ideal ‘attitude’ of the foetal head for the easiest labour
maximum flexion (head tucked) giving the minimum diameter of the head
what are some mal-attitudes of the baby during labour and what are the implications of these
90 degree extension - brow presentation
120 degree extension - face presentation
these have a higher chance for birth failure
what is the ideal position of the baby for optimal labour conditions
OA - face to floor
what are some positions associated with increased birth complications
OT (face to side) - may be transient as baby rotates 90 degrees in the birth canal but if it persists natural delivery is impossible
OP (face up)- 5% of births, highly difficult to deliver
how do you diagnose labour
effacement, dilation of the cervix
usually associated with rupture of the membranes but PPROM exists so not diagnostic
what are the substages of stage 1 of labour
latent stage - first 4cm of dilation, takes hours
active stage - 4-10cm, 1cm/hr nulliparous women, 2cm/hr multiparous women
how long is the active part of stage 1 of labour meant to be
<16 hours
what are the substages of stage 2 of labour
passive - no desire to push, full dilation of cervix-head hitting pelvic floor
active- when mother is pushing active pushing phase
how long does the active phase of stage 2 of labour usually take
40 mins nulliparous women
20 mins multiparous women
at what point do you begin to consider assistive options for birth during the active part of labour
> 1 hour
in what order should the baby come out of the vagina
head first, anterior shoulder, posterior shoulder, rest of baby
how long on average does it take the placenta to deliver
15 mins
what is a normal amount of blood lost post-partum
<500ml
what physiological response should occur that stops most of the post-partum bleeding
oxytocin release leads to uterine contraction which should constrict any bleeding vessels
what % of women get perineal trauma during labour
2/3 of nulliparous women, 1/2 of multiparous women
how are perineal tears graded
1st Degree - minor (pelvic floor muscles not involved)
2nd Degree - episiotomy grade, minor muscle involvement
3rd degree - anal sphincter involved (1%)
4th degree - anal mucosa torn
what are the general management principles of a woman in labour
temp and BP every 4 hours
Pulse every 1 hour in 1st stage, 15 mins in 2nd
contraction frequency should be every 30 mins
position - semi-recumbant
eating is ok unless anaethetics likely to be required
catheterisation if epidural, otherwise important to encourage urination
what should be done if a woman in labour’s temperature rises to >38
IV Abx and constant CTG monitoring required
what is associated with causing hyperactive labour
placental praevia
too much oxytocin/prostaglandin
how should you manage hyperactive labour
check for abruption
if you’re happy there is no abruption IV salbutamol as a tocolytic
generally most patients end up with a C section however
what augmentation of labour is available for nulliparous women
IV oxytocin
artificial rupture of membranes
what time period does oxytocin tend to work in for delayed labour
4 hours
what is the general advice in regards to pushing in labour
do not push until you feel an urge
when is instrumental delivery indicated for labor
stage 2 lasting for 1-2 hours
what is the difference between the use of augmentation of labour in multiparous and nulliparous women
you must exclude malpresentation in multiparous women before augmenting labour in any way
what is the initial management of an OP presentation in labour
rotation via keilland forceps/ventouse/manual rotation
what is the initial management of an OT presentation in labour
only relevant if delivery has not occured within an hour of the pushing stage
ventouse rotation
what is the management of a brow presentation in labour
C-section
what is the management of a face presentation in labour
flex head over perineum
if the chin is posterior c-section indicated
what is the highest permanent neonatal complication
cerebral palsy - 10% of all cerebral palsy patients
what are causes of foetal damage during labour
Foetal hypoxia/distress
Infection – mainly worried about GBS
Meconium aspiration leading to chemical pneuomitis
Trauma – usually due to instrumentation
Foetal blood loss
what test is done to check for neonatal hypoxia and what is a concerning score
foetal scalp pH
<7.2 = significant hypoxia
<7 = neurological damage likely
what are common causes of foetal hypoxia in birth
Placental abruption
Hypertonic uterine state
Use of oxytocin
Prolapse of umbilical cord
Maternal hypotension
what are labour related risk factors that are associated with foetal hypoxia
Prolonged labour
Meconium
Epidurals
Oxytocin
what are antepartum risk factors associated with foetal hypoxia at birth
IUGR
Pre-eclampsia
what are the signs of foetal distress/hypoxia
Meconium stained liquor – only if undiluted and <41 weeks
Abnormal foetal heart rate and ausciltation
Abnormal CTG <110 bpm, >160bpm Prolonged reduced variability (<5bpm) (>45mins-1 hour, to account for foetal sleeping) Decelerations Variable or late Early are usually benign
<7.2pH on foetal blood sampling
what are the indications for a CTG, prelabour and during labour
Pre-labour
Pre-eclampsia
IUGR
Previous c section
Previous Induction
Labour
Presence of meconium
Use of oxytocin
Maternal temp >38
Epidural
what is some non medical pain relief used in labour
preparation - antenatal classes presence of a birth attendant maintenance of mobility immersion in body temp water TENS hypnotherapy acupuncture massage aromatherapy
what are medical pain reliefs used in labour
inhalation - entonox
systemic opioids (IM) - pethidine/meptid
epidural - fentanyl + LA
spinal anaethesia
pudendal nerve blockade
what are systemic opioids associated with during labour
maternal confusion/drowsiness
foetal bradypnoea
when is a higher dose of epidural required
intrumental delivery
C-section
what is spinal anaethesia reccomended for during labour
C-sections
midsection delivery
what is a complication of spinal anaethesia during labour
hypotension
why is lying supine bad in pregnancy
IVC compression
what is pudendal nerve blockade appropriate for during labour
low-cavity instrumental deliveries
what is the general management of labour in stage 1
Mobility is encouraged
Supine avoided
If analegisia requested - entonox or epidural is given
Foetal heart rate monitored every 15 mins – abnormal means C-section
Progress measured every 4 hours
what is the general management of labour in stage 2
Pushing encouraged in women without an epidural if the head is visible or if the woman has the urge
If an epidural is in place pushing is nor encouraged for at least an hour
Oxytocin is given to nulliparous women or women with poor descent
Women with epidurals are encouraged to push 3 times for about 10 seconds during each contraction
If stage 2 is prolonged (2 hours nulliparous, 1 hour multiparous), or if there is foetal distress instrumental delivery is required
Episiotomy should be reserved for foetal distress or if the head is not passing over the perineum despite maternal effort
When the head starts to deliver the mother is asked to stop pushing and start panting, the birther will press on the perineum and head to prevent a too rapid delivery
On the next contraction, maternal pushing and gentle downwards contraction on the head should deliver the baby
what should be done immediately post delivery if the baby has a normal APGAR score
baby should be dried, wrapped and placed on the mothers chest
when should the cord be clamped post-delivery
should be left on for at least 1 minute unless resus is urgently required
what is the general management of stage 3 of labour
Once shoulders are delivered oxytocin IM is delivered
Active management of 3rd stage unpopular but it reduces PPH and the need for a blood transfusion
After the cord starts to lengthen, indicating placental separation, the cord is gently tugged whilst the suprapubic area is palpated to prevent uterine inversion
Placenta is checked for missing lobes and perineum for tears
Tears are sutured
Blood loss recorded
(<500ml normal)
Mother can be cleaned, made comfortable and encouraged to breast feed
Maternal observation should continue for at least 2 hours
what is the criteria for a retained placenta
stage 3 >30 mins
how many pregnancies have a retained placenta
2.5%
how should you manage a retained placenta
Partial separation may lead to considerable blood loss into the uterus and hypovolaemia
In the absence of bleeding 1 hour is left for natural separation, after which the placenta is manually removed
Blood is cross matched and IVAbx given
how are 1st and 2nd degree perineal repairs performed
Done under local anaethetic
Absorbable synthetic material is used with a continuous suture
Rectal and vaginal exam must be done to exclude sutures that are too deep and retained swabs
how are 3rd and 4th degree perineal tears repaired
Under spinal or epidural in a theatre
Antibiotics, analgesia and laxatives given
Follow up physio required
what % of pregnancies get 3rd-4th degree tears
1-3%
what % of women get long term sequale of labour
30% of women have long term sequalae – incontinence/urgency
when considering induction of labour, what does Bishop’s score measure and what are its components
Success of induction
consistency of the cervix (soft =higher)
Degree of effacement/early dilation
Station of the baby
Cervical position (OA/OP)
what Bishops score is the threshold for induction
8
what are common labour inducing agents
prostaglandin gels
amniiotomy +/- oxytocin
Oxytocin (used if membranes have already been ruptured)
Natural induction - cervical sweep
what is the effectiveness of a cervical sweep
50%
what are the indications for induction
Foetal Prolonged pregnancy IUGR Antepartum haemorrhage Poor obstetric history Premature rupture of membranes
Materno-foetal
Pre-eclampsia
Diabetes
Maternal
Social reasons
In utero death
if induction is medically indicated, what gestation is used
38 weeks
what are the absoloute contraindications for induction of labour
Acute foetal compromise
Abnormal lie
Placental praevia
Pelvic obstruction >1 c-section
what is the relative contraindication for induction of labour
> 1 c section + prematurity
how do you manage a labour once induction has been decided
Foetus is at risk due to drugs used – at least 1 hour CTG monitoring required
Increases the time spent in early labour – warn the mother
what are the complications of induction of labour
PPH
Intraprtum/postpartum infection
Prematurity
Instrumental deliver or C-section
what is a VBAC
vaginal birth after c-section
what are the contraindications for a VBAC
All absoloute indications for C-section
Vertical uterine scar
Previous uterine rupture
Multiple previous C-sections
what are factors associated with increased success for a VBAC
Spontaneous labour
Interpregnancy interval <2 years
Low age and BMI
Caucasian
Previous vaginal delivery
Previous elective C section
what is the risk of uterine rupture with a VBAC, and how does this change with successive C-sections
0.5% with 1, 1.3% with 2
what is recommended for labour day in a VBAC patient
hospital delivery + continuous CTG monitoring
how does a VBAC scar rupture present
Foetal distress
Scar pain
Cessasion of contractions
Vaginal bleeding
Maternal collapse
what % of women experience prelabour term rupture of membranes
10%
what % of prelabour, term rupture of membranes patients start labour within 24 hours
60%
what are risks of a prelabour rupture of membranes
cord prolapse
neonatal infection
management of prelabour rupture of membranes
Lie/presentation checking
Vaginal exam avoided
Foetal auscilatation
CTG
If spontaneous labour
Wait <24 hours
If meconium is present or there is materna infection, immediately induce
After 18-24 hours give prophylatic antibiotics to prevent GBS and to induce labour
If induced
No increased risk of c-section
Reduced risk of maternal infection
