Normal birth and intrapartum care Flashcards
define normal labour?
onset of regular painful uterine contractions associated with cervical effacement and dilatation
what is the normal dilatation diameter of the cervix during labour?
approx 10cm
what is the difference between spurious/false and normal labour?
regular painful uterine contractions NOT associated with cervical change
what do we mean by ‘breaking of waters’ in O+G?
Membranes rupture (membrane= fused chorion and amnion) –> release of amnion fluids
may either be spontaneous or artificial (where we cause it to occur)
why might we cause artificial rupture of the membranes?
Use it for induction of labour, and for augmentation of labour
Gives us an idea of fetal wellbeing- check volume of fluid and colour of fluid (meconium stain)
what do we mean by the ‘powers, passenger and passage’ during labour?
Powers= contractions frequency, timing, strength Passenger= baby's position, lie, presentation Passage= resistance to expulsion of baby from birth canal
what do we mean by the ‘lie of the baby’?
long axis of the baby vs the long axis of the mother
what are the difference between breech and cephalic presentation?
Breech= bottom first; longitudinal lie Cephalic= head first; longitudinal lie
what do we mean by the attitude of the baby?
degree of extension/flexion of the fetal neck
what do we mean by the position of the baby in the pelvis?
relationship of nominated part of presenting part to location on maternal pelvis
How do we detect pre-eclampsia?
HT and proteinuria
what are some things we should monitor for in a mother during labour?
Development of infection
Development of pre-eclampsia
Intrapartum haemorrhage
Pain control and emotional wellbeing
What are some ways we can manage pain during labour?
non-pharmacological= massage, relaxation, hot/cold packs etc
pharmacological= inhalational agents (NO, though not that effective), systemic analgesics (opioids), neuroaxial analgesia (epidural/spinal anaesthesia), local (pudendal nerve block, perineal infiltration)
how might we monitor fetal wellbeing during labour?
auscultation of fetal heart rate (intermittent auscultation, every 15mins; may be more frequent in high risk pregnancies)
amount and colour of amniotic fluid
describe the fetal hypoxic challenge during labour?
fetus experiences intermittent hypoxia as blood flow to placenta reduces by 40% every contraction
what do we mean by a ‘show’ in obstetrics
blood stained mucous plug at the cervix has displaced- usually occurs in the 3rd trimester (normal)
what do we mean by moulding, flexing and position of the fetal head during labour?
baby’s head is compressible and moulds as required during labour as it exits the birth canal through the bony pelvis
moulding= changes shape flexing= changes size position= changes rotation
what is the narrowest part of the bony pelvis that the baby has to pass during labour?
between the ischial spines of the pelvis
what do we mean by ‘has the baby engaged’ during labour?
has the biggest bit of the skull advanced past the ischial spines of the maternal pelvis?
what do we mean by the ‘station’ of the baby during labour?
its’ level above or below the plane of the ischial spines where ischial spines= 0 station)
what should you do if you notice that a baby has a cord wrapped around their neck during vaginal delivery?
clamp and cut the cord before the baby is born
how might we know that the placenta has separated after delivery of the baby?
you notice:
fresh blood in vaginal area
lengthening cord
uterus becomes firm and contracts
what is the most common cause of post partum haemorrhage?
uterine atony
describe first degree tear for perineal lacerations post vaginal delivery?
laceration of perineal skin or vaginal mucosa only
describe 2nd degree tear for perineal lacerations post vaginal delivery?
laceration extends into the submucosal tissues or musculature
describe 3rd degree tear for perineal lacerations post vaginal delivery and what must we do?
laceration involves the external anal sphincter –> risk of faecal incontinence
–> send them to theatre!
what might we monitor during labour for the mother and her baby?
Maternal-
Hourly BP, temperature, RR, time contractions, pain
Encourage urination every 2hrs
Fetal= CTG (if any increased fetal risk), or intermittent auscultation of the fetal heart rate
which women do we give antibiotics to during labour?
If GBS carrier (20%), or if prolonged rupture of membranes (suspected chorioamniotitis), or if has known heart valve disease –> risk of bacterial endocarditis
how do we assess clinically the progress of the labour?
abdominal palpation hourly
vaginal examination 4 hrly
what is the risk of GBS infection of the baby?
1 in 5 risk of fetal infection causing death or disability (CP)
what antibiotics do we use for prophylaxis against GBS?
intrapartum penicillin- IV given 4 hourly
if allergic to penicillin- clindamycin/erythromycin
what are some options for analgesia during labour?
- NO- reasonably effective (for short term); usually first or last analgesia used
- Narcotic analgesia- morphine, pethidine, fentanyl, (and heroin)–> mostly inadequate/ineffective
Regional analgesia- epidural, spinal, dermatomal
What is the dosage for morphine during labour?
10mg IM every 4 hourly
what is the dosage requirements of pethidine during labour?
100mg IM every 4 hours
where does spinal regional anaesthesia target?
subarachnoid space
what are some contraindications to regional analgesia
absolute- allergy to anaesthetic, infection at intended puncture site
relative- coagulopathy, systemic sepsis
how does an epidural cause hypotension?
leads to dilation of arterioles and venules, lowers TPR
- -> blood pressure falls
- -> pooling of blood in venules–> less venous return –> less CO
how might we manage hypotension due to regional anaesthasia?
manage with sympathomimetics (adrenergic agonists), give crystalloid fluids
what is the risk of using naloxone for opioid induced respiratory depression during labour?
the effect may wear off leading to undiagnosed later respiratory depression
why don’t we use colloid fluids during labour?
risk of anaphylaxis
what are the immediate SE of regional analgesia during intrapartum care?
- Hypotension–> manage with sympathomimetics, give fluids
- Total spinal block consequences–> muscular paralysis, circulatory collapse–> ADRENALINE (1:1000)
- Local anaesthetic toxicity
- Inability to push
what are the early post partum SE of regional anaesthesia during intrapartum care?
Pruritis • Dural puncture headache (postural headache)--> management= lie flat, volume replacement, +/- blood patch • Urinary retention • Back ache • Spinal haematoma Meningitis--> epidural abscess
how frequent should the uterine contractions be during labour?
typically 3-5 per 10 mins
what are some risk factors that indicate the need for continuous fetal heart monitoring during labour?
maternal risk factors= diabetes, hypertension, bleeding during pregnancy, morbid obesity, advanced maternal age,
fetal risk factors= suspected growth restriction, abnormal fetal heart rate, meconium stained liqour, preterm labour, breech presentation
when might we consider iv access in a woman going through labour?
if the woman is at high risk of PPH, is a carrier for GBS (requires antibiotics), caeserean section or prolonged labour > 12 hrs and risk of dehydration
what does continuous CTG stand for?
continuous cardiotocography
a woman going through labour has a recorded temperature of 38 degrees. what do you think of?
chorioamnionitis
what is the most favourable diameter for the fetal head as it goes through the pelvic inlet?
the suboccipitalbregmatic diameter achieved by flexion of the head and vertex position
what are the two vital haemostatic mechanisms by which the body prevents post-partum haemorrhage as the placenta separates?
- compression of the uteroplacental blood vessels by the retracted uterine muscle fibres
- through normal vascular haemostasis through vasospasm, platelet aggregation and clot formation.
what is uterine atony?
decreasing uterine contractions during labour due to ‘uterine fatigue’. significant risk factor for PPH
what do we mean by restitution or external rotation of the fetal head during delivery?
the fetal head turns laterally such that the shoulders descend through the AP (widest) diameter of the pelvis
once the fetal head has external rotated and the shoulders are ready for delivery, how does the rest of the delivery proceed?
anterior shoulder is delivered under the symphysis by gentle downward traction
posterior shoulder is delivered by elevation of the head
rest of the body is delivered by gentle downward traction of the shoulders
what are the 3 components of ACTIVE management during stage 3 of labour? why do we do this?
1) administer oxytocin and await uterine contraction
2) assist placenta delivery using controlled cord traction
3) early cord clamping
active management reduces risk of PPH
define augmentation of labour
stimulating labour that has already commenced
define induction of labour
causing labour to commence
what are some reasons to NOT induce labour?
- Prematurity
- Breech presentation or transverse lie
- previous caesarean section
- placenta praevia
- fetal growth restriction and fetal compromise
in some cases, c-section may be a better option instead of induction. e.g. fetal growth restriction + fetal compromise, transverse lie and placenta praevia
what are some complications of induced labour?
cord prolapse when amniotomy is performed
may cause fetal distress
may lead to uterine hyperstimulation due to prostin or syntocinon
describe ARM or amniotomy during induction of labour?
ARM= amniotomy (artificially break the waters)–> can only be done when the cervix is dilated a few cm.
A hook or small toothed forcep is used to rupture the forewaters.
Don’t generally do an amniotomy if the baby’s head is not well applied to the cervix as there is a risk of cord prolapse if not.
how might we initiate the process of induction of labour in a woman who has an undilated cervix?
Prostaglandin gel–>
inserted into the vagina, softens the cervix. Used when cervix is closed as it dilates cervix.
what are some precautions we have to consider before using prostaglandin gel in induction of labour?
Precautions: may induce uterine hyperstimulation; should not be used if the woman has had previous c-section or presents with ruptured membranes.
CTG monitoring is used before and after administration
what is some SE of syntocinin?
nausea, vomiting, water intoxication and hyponatremia.
how might we administer syntocinin during induction of labour?
Administered via an IV infusion pump and titrate dose accordingly. Once you have good contraction frequency then correct dose is reached. Dosage is between 1-32 milliunits/ml.
what is the role of instrumental delivery during labour?
instrumental delivery is used to facilitate or expedite vaginal delivery
what are the two tools we can use for instrumental delivery during labour?
Forceps or the vacuum device
why might we do instrumental delivery during labour?
May be indicated during prolonged second stage of labour
–> maternal exhaustion, excessively effective epidural (unable to push), malposition of presenting part or fetal distress necessitating expedition of delivery
what are some conditions you must fulfil to perform instrumental delivery?
cervix must be fully dilated
fetal head must be engaged
membranes must be ruptured
cephalic presentation
appropriate analgesia available
catheter passed- bladder is empty
appropriate resuscitation facilities available
trained obstetrician in episiotomy if required (esp if forceps are used)
what is the lithotomy position during labour?
woman is lying on back and legs up in stirrups during labour
why might an episiotomy be required if forceps are used during labour?
forceps encircle the baby’s head, which may increase the diameter of the head. This may make the delivery a ‘tight fit’ and episiotomy is often required
in what anatomical position in the pelvic inlet should the fetal head be to use neville barnes forceps during delivery?
fetal head must be anterior!
what is the role of keilland’s forceps during labour?
keilland’s forceps are used to rotate a posteriorly positioned fetal head to anterior position
then neville barnes forceps can be used
what are some complications of instrumental delivery?
Excessive force or incorrect use of the forceps may result in facial nerve palsy, bruises, intracerebral bleeding in the fetus or damage to the fetal cervical spine
instrumental delivery often associated with more damage to the maternal perineum
what does intrathecal anaesthesia mean?
inject anaesthetic directly into the CSF
what is the difference between an epidural anaesthetic and a spinal anaesthetic?
epidural- anaesthetic injected into the epidural space
spinal- anaesthetic directly injected into the CSF
what are some contraindications for an epidural?
absolute CI- patient refusal
relative CI- hypovolemia (bc of sympatholytic effect of epidural causes hypotension), coagulopathy, sepsis, active neurological disease, ?fetal distress
what are the advantages of using an epidural during labour?
very effective pain relief
no sedative effect
improves placental blood flow in some cases such as preeclampsia
allows instrumental delivery
what are some complications of using an epidural during labour?
- sympatholytic effect= hypotension
- push needle too far into the CSF –> causing dural puncture headaches
- can cause high block or total spinal block
- can be accidentally injected into the intravascular space
- risk of infective and bleeding complications (epidural haematomas)
what is a blood patch and when is it used?
inject some maternal blood into the CSF space in the setting of a dural puncture to manage dural puncture headache from epidural
what is a common drug combination used for epidurals?
Ropivacaine (LA) + fentanyl (opioid)–> synergistic effect
a pregnant woman decides she wants an elective C-section. what kind of anaesthetic will she typically receive during labour?
spinal analgesia
how might we manage postpartum pain in a woman who has just given birth?
multimodal analgesia
- e.g. regular paracetamol, NSAiD and oxycontin
- PRN tramadol for breakthrough pain
- PCA (patient controlled analgesia is an option but rarely used)
what is the pathophysiology of shoulder dystocia?
fetal bisacromial diameter is too wide for the AP diameter of the maternal pelvis
- -> it is a bony obstruction
- -> unique to vaginal cephalic presentation
what are some fetal complications of shoulder dystocia?
bone fracture in the clavicle etc
transient/permanent brachial plexus palsy
death
asphyxia –> CP
what are some maternal complications of shoulder dystocia?
birth canal trauma inc anal sphincter injury
haemorrhage
uterine rupture
psychological impact
what are the aims of performing manouveres in suspected shoulder dystocia?
- increase the functional size of the bony pelvis
- decrease the bisacromial diameter of the fetus
- change the relationship of the bisacromial diameter within the bony pelvis by rotating the fetus into the wide oblique diameter
how long do we spend per manouevre when managing shoulder dystocia in labour?
30 seconds per manoueuvre
why are uterine contractions important in labour, even with c-sections?
reduces risk of PPH
and so in c-sections, often augmented with oxytocin
other than using prostaglandin therapy for cervical ripening during induction of labour, what other method can we use to dilate the cervix?
foley transcervical catheter
Balloon catheter left in overnight; falls out itself when cervix is dilated
what are the types of episiotomy cuts?
median
mediolateral
J shaped
what are some indications for caesarean sections?
previous caesarean delivery obstructed labour inadequate progress in labour/fetal compromise transverse or oblique lie major placenta praevia/vasa praevia/ multiple pregnancy severe preeclampsia maternal request
what do we mean by left lateral tilt?
raise the right hip of the mother to reduce compression on the great vessels
what do we mean by ‘active management of third stage labour’
Active management of the third stage of labour consists of interventions designed to facilitate the delivery of the placenta by increasing uterine contractions and to prevent primary postpartum haemorrhage (PPH) by averting uterine atony. The usual components include administration of uterotonic agents, controlled cord traction and uterine massage after birth of the placenta, as appropriate
how do we administer oxytocin to actively manage the 3rd stage of labour?
Oxytocin (10 units IV or IM) is preferred over other uterotonic drugs because it is effective 2-3 minutes after injection, has minimal side effects and can be used in all women.
• Administer a prophylactic oxytocic agent to the woman with the birth of the anterior shoulder, or within one to two minutes of the birth of the baby
• Clamp and cut the umbilical cord close within 2-3 minutes of administration of the oxytocic.
Note: It is important to delay this action until after the oxytocic has been administered.
• Immediately after cord clamping place one hand on the uterine fundus and await the onset of a strong uterine contraction. This is likely to occur within 2-3 minutes after oxytocic administration
what are the clinical features that may indicate onset of labour?
Clinical evidence of the onset of labour includes:
- Basic prerequisite: painful contractions at intervals of less than 10 minutes
- Highly suggestive: spontaneous, bloody show or rupture of membranes
- Objective proof: full effacement of the cervix- particularly in primigravidas
what is the risk of letting ‘nature take its course’ in a postdates pregnancy rather than induction?
increased chance of stillbirth due to placental insufficiency > 40 weeks
what are the contraindications to an internal vaginal examination during the antenatal/intrapartum period?
rupture of membranes
placenta praevia
what scoring system do we use which may help guide induction of labour
Bishops score of the cervix-
Vaginal digital examination to determine degree of cervical dilation.
If bishops score is less than 6, prostaglandin gel or balloon catheter may be used to ripen the cervix.
if bishops score > 6, amniotomy and oxytocin infusion can commence
what are some tocolytics we can use in the intrapartum period to delay labour?
nifedipine
salbutamol
terbutaline
what is the risk of using prostaglandins in induction?
The principle concern with prostaglandin administration is the risk of excessive uterine muscular activity. The clinical consequences are twofold. First, there is a reduction in uteroplacental blood flow with every uterine contraction. If the sufficiently intensive contractions are excessively frequent (> 5 in 10 minutes) or of excessive duration (> approximately 70 seconds), placental oxygenation will fall and the fetus will become first hypoxic and then acidotic. Excessively frequent contractions is termed uterine tachysystole. Where this results in fetal compromise, it is termed uterine hyperstimulation.
The other consequence of excessive uterine muscular activity is the possibility of excessive thinning of the lower uterine segment as the upper segment contracts (and retracts) vigorously around the fetus. This can result in uterine rupture, most commonly from a tear within the lower uterine segment. A less than full thickness tear can result in a uterine vein being torn, with intrauterine pressure forcing amniotic fluid into the maternal blood stream.
what are some contraindications to vaginal breech delivery?
Cord presentation
• Fetal growth restriction or macrosomia
• Any presentation other than frank or complete breech
• Extension of the fetal head
• Clinically inadequate maternal pelvis
• Fetal anomaly incompatible with vaginal delivery
what are the contraindications for external cephalic version for breech baby?
- where caesarean delivery is required
- antepartum haemorrhage within the last 7 days
- abnormal cardiotocography
- major uterine anomaly
- ruptured membranes
- multiple pregnancy (except delivery of second twin).
when do we perform ECV for breech baby?
> 37 weeks
what are the contraindications for trial of labour?
The following conditions are highlighted as being associated with an increased risk of uterine rupture
or unsuccessful TOL:
- Previous classical or vertical lower uterine segment incision
- More than one previous caesarean section
- Less than 18 months since the previous caesarean section
- BMI >40
- Fetal weight > 4 kg.
what are the contraindications for VBAC?
Two or more previous C/S
• Previous classical, inverted T or J incision
• Previous uterine rupture
• Myomectomy that breached uterine cavity
• Medical or obstetric reason for a repeat C/S
how might we clinically determine whether a pregnant woman is going into labour at term?
- Is there show? –> if Y then likely
- What is the station of the baby? –> if low then likely
- Any contractions? –> If Y and of high intensity (4 in 10 mins, 60s duration) then likely
- Ruptured membranes? If Y and near term, then likely
what is the routine monitoring for the labouring mother in a LOW risk, normal pregnancy?
Temperature every 4 hours, BP/Pulse every hour, RR every 4 hours, VE (if no contraindications) every 4 hours
what is the routine monitoring for fetal wellbeing during a low risk normal labour?
intermittent auscultation of the fetal heart beat every 15-30mins in 1st stage labour, or during/after every contraction in 2nd stage labour
when is cord blood sample sent off post delivery of baby?
After the baby is born, cord blood is only sent off if rhesus-negative mother and at risk of rhesus antibody formation.
when do we give syntometrine vs oxytocin and then ergometrine during labour?
syntometrine IM is given to women at risk of PPH such as previous PPH, risk factors for uterine atony etc
oxytocin infusion and then ergometrine are used in active management of acute PPH in a stepwise fashion if no contraindications to ergometrine
