Labour Flashcards
Labour defn?
painful uterine contractions accompany dilatation and effacement of cervix
how many stages does labour have?
3
First stage labour?
initiation to full cervix dilatation 10cm
second stage of labour
cervical dilatation to delivery of fetus
third stage of Labour?
delivery of placenta
what factors determine labour?
3 factors
Power - degree of force pushing fetus
passenger- fetus head diameter
passage - dimension of pelvis and resistance of soft tissue
Uterine contractions
45-60seconds every 2-4 minutes
pulling cervix up (effacement)
= dilatation
effacement?
thinning and shortening of cervix
The passage
bony pelvis
Pelvis inlet diameter
around 13 cm transverse
anteroposterior is 11cm
what is level of descent?
the landmark that is used is the ischial spines
this is measuring descent of head
level of descent of the head is known as the station in relation to ischial spines
what is station 0?
station 0 means head of fetus is at the ishcial spines
station -2 means?
head is 2cm above ischial spine level
anterior fontanelle
posterior?
bregma
occiput
what is vertex presentation?
maximal flexion of fetus head, head bowed
presenting diameter would be 9.5cm anterior fontanelle to below occiput
why must the fetus head rotate during delivery?
if sagital suture is transverse at point of entering pelvic inlet - fits best
but at outlet the sagittal suture must be vertical for head to fit to pass out
so rotation by 90degrees is needed to get this
delivering occiput-anterior
can you deliver occiput-posterior
yes but more complicated only 5%
you can’t deliver occipto transverse
oxytocin produced where?
posterior pituitary gland
aids stimulation of contractions
prostaglandins stimulate this and help reduce cervical resistance
First stage of labour is split into?
this stage involves rupture of membrane
latent stage: dilates to 4cm
active phase: 1cm/hr in nulliparous, 2cm/hr in multiparous (should not last longer than 16 hours?)
passive second stage
Dilatation of cervix to delivery of fetus
lasts till head reaches pelvic floor - rotation and flexion are done by now
can last a few minutes
active second stage
mother is pushing
pressure of head
40-20 mins
> 1 hour means spontanous labour won’t occur
placental delivery
lasts upto 15 mins
upto 500ml of blood loss is normal
10 steps of labour
- Descent
- Engagement – identified by abdominal palpation, foetal head is 3/5th palpable or less
- Neck flexion
- Internal rotation
- Crowning
- Extension of the presenting part
- Restitution
- External rotation
- Lateral flexion
- Delivery of the shoulders and foetal body
risk factors for foetal compromise?
maternal factors
previous C section
hypertension
PROM
vaginal blood loss
maternal sepsis/ chorioamniontis
GDM
hyperactive uterine activity
causes
imapct
fetal distress as placental blood flow is impaired
associated with abruption
prostaglandin use
too much oxytocin
tocolytics
suppress uterine contractions
most common tocolytics
magnesium sulfate
CCB - nifedipine
NSAIDS: indomethacin
b2 agonists : terbutaline / salbutamol (IV or subcut)
effects of tocolytics
CCB
block calcium channels
inhibits calcium ions
reducing contractility - smooth muscle relaxation
effects of magnesium sulfate
neuroprotective - useful in preterm brain
effect of nsaids on prostaglandins
inhibit COX enzyme (this typically stimulates prostaglandin production)
reduced prostagland levels
relaxation of uterine muscles
fetal distress defn
hypoxia that might result in fetal death / damage if not reversed or delivered
how is fetal distress measured?
<pH 7.2
fetal distress steps
intermittent auscultation of fetal heart
continoud CTG
Fetal blood sampling
delivery
when is Continous CTG indicated
fetal factors
fetal growth restriction
anhydramnios or polyhydramnios
advanced gestational age
small for gestational age
non cephalic presentation
what is polyhydramnios
what is a normal amount?
increased volume of amniotic fluid
comprises of fetal urine output
500ml
causes of polyhydramnios?
anything that prevents fetus from swallowing
(obstruction of oesophagus, neuro problems, atresia etc)
increased lung secretions like in CF
types of pain relief
medical
entonox (NO)
opiates
epidural
why is supine position avoided in pregnant women?
Gravid (heavy) uterus compresses main blood vessels > CO reduced> hypotension = fetal distress
what is aortacaval compression?
supine lay in a gravid women causing reduced CO and hypotension leading to fetal distress
fever of 38 degrees in labour?
risk of neonatal illness (? chorioamnionitis)
>37.5 bad
cultures of vaginal, urine and blood taken
paracetamol given IV abx
cTG monitoring
Bishop score of 8?
Favourable cervix likely to progress spontanously
Bishop score of <6?
induction needed
offer vaginal prostaglandin
bishop score of 7?
ARM followed by IV oxytocin
prostaglandin E role in IoL
gel/slow release into psoterior vaginal fornix
activates prostaglandin e2
soften cervix and dilates blood vessel
amniotomy?
amnihook (instrument used) ruptures waters then you give oxytocin within 2 hours
natural inductions?
membrane sweep
releases physiological prostaglandins
offered at 40 weeks for nulliparous
41 multiparous
indications for IoL
Fetal causes:
prolonged pregnancy
IUGR
anterpartum haemorrhage
prelabour term rupture of membranes
indications for IoL
materno-fetal causes
pre-eclampsia
maternal diabetes
previous caesarian
maternal request
breech
fetal macrosomia
contraindications for IoL
acute fetal compromsie CTG/lie
placenta praevia!!!
prostaglandin e2 gel?
Prostin®
prostaglandin e2 pessary?
propess
what is cervical ripening balloon?
catheter inserted into cervix which can mechanical induce labour
safe for baby
less risk of uterine hyperstimulation
define risk for CTG
maternal factors?
previous c-section
pre-eclampsia
antepartum haemorrhage
post term pregnancy
rolonged rupture of membrane >24 hours
significant maternal disease
what is delay in first stage?
<1cm per 2 hours
how to manage delay?
ARM review in 2 hours
oxytocin
types of delay?
primary dysfunctional labour
secondary arrest of labour (progressed well then stopped)
prolonged latent phase
cervical dystocia
what is delay in second stage?
Nulliparous women
from active second (cervix dilated to 10cm)
3 hours with epidural
2 without epidural
what is crowning?
when head no longer recededs between contractions
immediate care of neonate?
when do you need to start continuous CTG monitoring?
contractions?
contractions last longer than 2 mins
5 or more contractions in 10 minutes
when do you need to start continuous CTG monitoring?
infection risk factors
maternal pyrexia
chorioamnionitis
sepsis
when do you need to start continuous CTG monitoring?
relating to maternal obs
pulse over 120 bpm on 2 occasions more than 30 mins apart
severe hypertension >160/110
hypertension 140/90
protein 2+ and raised bp>140/90
fresh vaginal bleed
abnormal pain
blood stained liqour
when do you need to start continuous CTG monitoring?
other
insertion of regional anaesthetic
use of oxytocin
immediate care of newborn
when is apgar score calculated?
what is a normal score?
1 minute
5 minute
> 7 is good
what apgar score is most worrying?
0-3
when is vit K given?
why?
immediately
to prevent vit K dependent bleeding
apgar score
appearnace
pulse
grimace
activity
respiration
APGAR heart rate?
what scores 2
> 100 beats/min scores 2
APGAR score heart rate what scores 1?
<100 bpm
SCore 0 for APGAR
HR: absent
RR: absent
muscle tone: flaccid
reflex: none
colour: plae/blue
apgar score what scores 1?
<100bpm HR
gasp/irregular : Respiratory effort
flexion of limbs : muscle tone
grimace : reflex irritability
body pink , extremities blue : colour
what scores 2 on apgar?
> 100beats per minute : HR
regular strong cry : respiratory effort
well flexed/ active : muscle tone
cry/ cough : reflex irritability
pink :colour
causes of PPH?
tone - atony most common
tissue - retained products
trauma - (laceration)
thrombin - coagulopathy
how to manage meconium aspiration?
no history of GBS?
observation recommended
41 week old delivery has asymmetrical patchy opacities on chest x-ray
mother had a temp of 38 at delivery
what is this?
how to manage?
what else can be offered ?
meconium aspiration
sign of infection so IV ampicillin and gentamicin
CPAP and/or oxygen therapy
boluses of surfactant
inotropes
what is prelabour term rupture of membrane also known as?
premature rupture of membrane
so baby at term 37 weeks but waters break before uterine activity has started
what two signs in PROM indicate immediate IoL?
presence of meconium
positive group b strep results (from vaginal swab?)
PROM management?
admit
speculum
(vaginal swab sent for infection)
4 hr temp
24hr foetal monitoring
how long can you give expectnat management for PROM (from when membranes rupture)?
24 hours 60& will deliver sponatanously
what is preterm prelabour rupture of membrane?
before 37 weeks rupture of membrane without uterine activity
here you want to prevent and protect foetus because it is not fully developed
particularly before 34 weeks
diagnostic Investigation for PPROM / PROM?
speculum (amniotic fluid pooling is diagnostic)
look at os (open/closed)
pooling
then test IGFBP-1 / PAMG-1
if >30 weeks contractions are present and Os is closed whatd o you do?
why?
what does this tell you?
TVUSS for cervical length
<15mm likely to preterm labour
>15mm unlinkely to be preterm labour
can you offer tocolysis for P-PROM?
no due to increased risk of infection
Mx of P-PROM
admit (at least until 28 weeks then depends but seen 2/3x weekly)
sterile speculum exam
offer Abx: erythromycin (2nd line penicillin)
offer maternal corticosteroids (IM betametasone 24mg)
offer IV magnesium sulfate (if birth expected in 24 hours)
when in p-prom do you immediately offer IoL?
> 34 weeks
group b strep signs
what is abx given in pprom?
1st line erythromycin QDS 250mg
2nd line penicillin
dose of magnesium sulfate and why is it given in PPROM?
IV
neuroprotection of foetus especially if <30 weeks
effects after 30 weeks are unclear
corticosteroid in PPROM?
IM betametasone 24mg / in 2 doses 12 hours apart
assists with lung maturation (if less than 34 weeks
risk factor for pprom /prom?
smoking
sti
previous hx
multiple pregnancy
PROM
risk of infection to neonate?
how many women will go into labour by 24 hours
complication?
1% compared to 0.5% of intact
60%
attempt to induce at 24 hours
risk of ascending infection
complication of pprom?
maternal: sepsis, cord abruption
foetal: chorioamnionitis, cord prolapse, pulmonary hypoplasia, death
preterm labour can be classified into?
PTL : 32-37
very PTL: 28-32 weeks
Extremely PTL: <28
causes of preterm labour?
infection
overdistention of abdomen?
polyhydramnios
multiple pregnancy
predicting preterm labour
how many factors?
how many do you need to be offered prophylaxis?
previous Hx of spontanous birth <34 weeks
mid trimester loss (>16 weeks )
cervical length <25mm on USS
if 2 then defo offer
if 1 then sugggest
prevention of pre term labour
mx?
vaginal progesterone started 16-24 and continue till 34 weeks
cervical cerclage
contraindications to rescue cervical cerclage?
bleeding
infection
uterine
contractions
mx of preterm labour?
admit
offer maternal steroids
offer tocolytics
Iv magnesium sulphate
aim for delivery 37 weeks
tocolytic use in preterm labour?
1st line nifedipine (CCB)
2nd line atosiban oxytocin receptor antagonist
dose of magnesium sulphate?
4g over 5-15 mins IV infusion of 1g/hour
continue till birth or 24 hours
antidote to mgso4
10ml 10% calcium gluconate over 10mins (and stop magnesium
sulphate infusion
complications of pre term birth?
RDS > retinopathy of prematurity
necrotising enterocolistis
intraventricular haemorrhage
periventricular leukomalacia
