Labor Flashcards
When to deliver CS if multiple pregnancy?
if the first twin is in the breech position, placenta previa, and pregnancy greater than three. If the twins are mono zygotic (not an absolute C/I).
intrapartum risks for multiple pregnancy
malpresentation, fetal hypoxia, cord prolapse, operative delivery, post-partum heamorrhage
rare: cord entanglement (MCMA) ]head entrapment, fetal exsanguination due to vasa praevia.
When are twins induced?
38 weeks gestation
What is the workup before induction of labour in a twin pregnancy?
- IV access and group and save
- set up the CTG- fetal monitoring (aviod hypoxia in the second twin)
- epidural consent
- get the labour in theatre
Management of labour in a twin delivery
- support mother
- monitor both fetuses (scalp probe and abdominally)
- after delivery of the first baby, the second twin is stabilised and VE preformed
- twin is delivered within 20 minutes of the first
- use oxytocin after the first twin
- breech extraction
causes of breech presentation
idiopathic preterm delivery previous breech presentation uterine abnormalities (fibriods) placenta pravia fetal abnormalities multiple pregnancy
complications of breech presentation
increased risk of hypoxia and trauma in labor.
when you can diagnose breech presentation
36 weeks and the lie can be palpated and presenting part is not hard and fetal heart is heard high up on the uterus.
External cephalic version
preformed at 36 wks in nulliparous and 37 wks in multiparous ones, success rate 50%
complications are pain, placental abruption and fetomaternal hemorrhage.
increasing the success of EC version
tocolysis- causes tachycardia
contraindications of ECV
CS already indicated, antpartum heamorrhage, fetal compromise, oligohydramnios, rheus immunisation, and pre-eclampsia.
ideal vaginal delivery for breech
fetus is not compromised, fetal weight is less then 4kg, spontaneous onset of labour, extended breech presentation, non-extended neck.
delivery technique breech
lovset’s manoevre
preterm labour
delivery less than 34 weeks
complications of preterm labour
cerebral palsy, blindness, deafness
risk factors for preterm delivery
previous preterm delivery or late miscariiage, multiple pregnamcy, LLETZ procedure or cervical surgery, uterine anomalies, medical conditions, pre-eclamplsia and IUGR.
Acute pre-term labour associated with?
cervical weakness- triad- increased vaginal discharge, mild abdominal pain, and bulging membranes. infection, inflammation and abruption.
What to ask in the history of preterm labour?
apin and contraction (onset, freq, duration, and severity
vaginal loss: SROM or PV bleed
obs history
examination in preterm labour
maternal pulse, temp, RR
uterine tenderness (infection, abruption)
fetal presentation
speculum blood discharge, liquor take swabs
gentle VE
investigations in preterm labour
FBC and CRP (raised in infection)
swabs and MSU
USS for fetal presentation and estimated fetal weight
fetal fibronectin or tranvaginal USS
management of preterm labour
Is it threatened or real labour
admit if high risk
inform the neonatal unit
arrange in utero transfer
check fetal presentation with USS
steroids 12 mg betametasone IM two doses 12 hours apart.
consider tocolysis- to prevent labour and delivery, but for greater than 24hrs.
liason with senior obs and peads (23-26wk) clear plan mode of delivery, monitoring in labour, and presence of specialist at delivery. give IV antibiotics, but only if labour is confirmed.
how to establish if it is real or threatened preterm labour
tranvaginal cervical length scan (greater than 15 mm unlikely)
fibronectin assay negative unlikely to labour).
Antenatal steroids which dose and why useful
betamatasone IM two doses 24 hrs apart
reduce the rates of resp. distress, intraventricular heamorrhage and neonatal death.
how to prevent preterm labour
treat bacterial vaginaosis, progesterone in high risk woman or woman with a short cervix surgical sutures (cerclage)
treatment of bacterial vaginosis
clindamycin
surgical sutures for treatment of preterm labour indications
- elective (prior loss due to cervical weakness)
- US indicated
- rescue procedure
transvaginal ultrasound of cervix for preterm labour
asymptomatic risk of delivering before 32 weeks is 4% if cervix is greater than 15mm long at 23 wks
if cervix is 5 mm 78% risk
symptomatic
less than 15mm risk of delivery within a week is 49%
if greater than 15mm risk is less than 1%
fetal fibronectin
not present normally in 22-36week
if positive more likely to deliver.
preterm prelabour rupture of the membranes etiology
complicates 1/3 of preterm deliveries
history of premature rupture of memebranes
ask about vaginal loss gush or constant trickle or dampness
features of chorioamnionitis
history: fever, malaise, abdominal pain, purulent offensive vaginal discharge.
exam:
maternal pyrexia and tachy
uterine tenderness
fetal tachycardia
speculum offensive discharge yellow or brown
investigations for premature rupture of the membranes
FBC, CRP (raised WCC and CRP- infection) high and low vaginal swabs MSU USS for fetal presentation EFW and liquor volume
management of premature rupture of the membranes
if evidence of chorioamnionitis 1. steroids 2. deliver whatever gestation if no evidence 1. admit and inform NICU 2. steriods 3. erythromycin
what antibiotic should be avoided in treating premature rupture of the membranes?
co-amoxiclav
what is the prognosis of surviving premature rupture of the membranes?
less than 20= few
greater than 22 up to 50%
what are the fetal risks for PPROM?
prematurity
infection
pulmonary hypoplasia
limb contractures
definition of prolonged pregnancy and incidence
pregnancy that exceeds 42 weeks from LMP, 10%
fetal risk of prolonged pregnancy
perinatal mortality (intrapartum deaths 4x as common and early neonatal death 3x common)
other risks:
meconium aspiration
oligiohydramnios
macrosomia, shoulder dystocia, erbs palsy
cephalhaematoma
fetal distress in labour
nenatal- hypothermia, hypoglycemia, polycythaemia, and growth restriction
fetal postmaturity syndrome
management of a prolonged pregnancy
confirm EDD
offer a stretch and sweep at 41 weeks
offer induction of labour between 41 and 42 wks reducing perinatal mortality, reduces the risk of CS, ensure fetal surveillance.
fetla monitoring- USS assessment of growth and amniotic fluid. daily CTGS after 42weeks,
RF that would be an indication to induce early
pre-eclampsia, diabetes, antepartum heamorrhage
what is labour?
Labour is the process by which the foetus is delivered after the 24th of gestation.
what is the onset of labour?
at the point by which the uterine contractions become regular and cervical effacement and cervical dilatation becomes progressive.
what is labour characterised by?
onset of contractions which increase in duration, frequency, and strength over time
cervical effacement and dilatation
rupture of membranes with leakage of amniotic fluid
decent of presenting part through the birthing canal
birth of the baby
delivery of the placenta
What is the birthing sequence?
engagement and decent: head enters the pelvis in the occipital transverse position and then flexes its head.
internal rotation to occipitalanterior: occurs at the level of the ischial spines
Crowning: the head extends, descending the perineum until delivered
Restitution: the head rotates so the occiput is in line with the fetal spine.
external rotation: the shoulders rotate when they reach the level of the lavatory muscles until the biacromal diameter is anteroposterior
delivery of the anterior shoulder
delivery of the posterior shoulder
The first stage of labour latent phase
the period taken for the cervix to completely efface and dilate up to 3 cm
1st stage of labour active phase
from 3 cm to full dilatation (10cm)
failure to progress in first stage of labour
there is less than 2 cm dilatation after 4 hours
slowing in progress in parous woman
causes of failure to progress in the first stage of labour
inefficient uterine activity
malpositions, malpresentation, or large passenger
inadequate pelvis
a combination of the above
poor progress in the 1st stage assessment
review the history- is there any diabetes? look at previous scans?
was there an abnormal lie, palpate the abdomen, frequency and duration of the contractions
review fetal condition= heart rate, colour and quantity of fluid
review maternal condition- hydration status
vaginal assessment- cervical effacement, dilation, caput, moulding, position, and station of the head
poor progress in the 1st stage of labour = management
amniotomy (artificial rupture of the membranes) reassess in 2hr
amniotomy plus oxytocin infusion and reassess in 2 hr (nulliparous)
lower segment CS if fetal distress
monitoring in labour
FHR every 30 minutes contractions every 30 minutes maternal pulse checked hourly BP and temp checked 4 hrly VE every 4 hr to check progress maternal urine tested 4 hrly for ketones and protein
Labour 2nd stage definition
the time from full cervical dilation until the baby is born
labour second stage, how much time is allowed for passive decent before active pushing is commenced?
1 hr
How long should the second stage of labour last for nulliparous woman and multiparous woman?
nulliparous- 3h
multi- 2 hr
describe a normal 2nd stage of labour
the active stage commences when the mother starts using her abdominal muscles with the valsalva manoeuvre to bear down
woman choose different positions to deliver in squatting, standing, or supine.
as the head comes down it descends the perineum and anus, control the rate of delivery of the head
with the next contraction gentle traction guides the head towards the perineum until the anterior shoulder is delivered under the suprapubic arch.
gentle traction upwards and anteriorly helps deliver the posterior shoulder
cord double clamped and cut delaying clamping leads to higher hemt levels in the infant
APGAR score
delay in the second stage of labour management
nulliparous- suspect if not in the hour of active pushing
2 hr- call obstetrician
multiparous women- requires review by obstetrician after one hour of active pushing.
3rd stage of labour definition
the duration of time from the delivery of the baby to the delivery of the placenta.
active management of the third stage of labour
- use of uterotonics
- clamping and cutting of the cord
- controlled cord traction
benefits of active management of the third stage of labour
decrease the rates of PPH, blood loss, postnatal anaemia, length of third stage, and need for blood transfusion.
adverse effects of active mgx of third stage
nausea and vomiting
headache
physiological management of the 3rd stage of labour
no oxytocin or syntometrin given
cord is allowed to stop pulsing before it is cut
the placenta is delivered by maternal effort alone
when should physiological mgx be changed to active mgx in third stage of labour?
heamorrhage
failure to deliver placenta in 1hr
maternal desire to shorten 3rd stage
description of an actively managed third stage
oxytocin 10IU IM given as the anterior shoulder of the child is born
dish placed at the introitus to collect the placenta and any blood loss the left hand is placed at the uterine fundus
as the uterus contracts the placenta separates
the cord will lengthen and there is a trickle of fresh blood
controlled cord traction applied while supporting the fundus (brant-andrew technique)
induction of labour aetiology
10-20% of labours induced
chance of receiving a vaginal birth after 34 weeks is less than 35 %
obstetric indications for the induction of labour
uteroplacental insufficiency prolonged pregnancy (41-42wks) oligo or a hydranmios abnormal uterine artery doppler non reassuring CTG PROM severe pre-eclampsia or eclampsia after maternal stabilisation IUD unexplained antepartum heamorrhage chorioamnioitis
medical indications for induction of labour
severe hypertension
uncontrolled DM
renal disease with deteriorating renal function
malignancy
what is cervical ripening? What is the mechanical mechanism to bring this about?
one of the Bishops score of the cervixm the mechanism of which is separation of the membranes from the cervix leading to the local release of prostaglandins.
A common method to bring this about is artificial separation.
This needs to accommodate a finger and 30% will go into spontaneous labour in less than 7 days
What are the pharmacological methods of cervical ripening?
prostaglandin (dinoprostone) - given into the posterior fornix
oxytocin infusion: shown to increase prostaglandin levels use after membranes have ruptured.
Describe the Bishops score
Position of the cervix- anterior axial anterior
length of the cervix
consistancy of the cervix
dilatation of the cervix
station of the presenting part in relation to the ischial spine
methods of inducing labour
amniotomy
if then no regular painful contraction after 2 hrs then oxytocin infusion should be commenced
starting oxytocin at the time of amniotomy shown to decrease th risks of maternal and fetal sepsis
prostaglandins for the induction fo labour
first do a CTG 30 minutes before
VE after 6 hr if the cervix is not favourable another dose can be administered. Oxytocin should NOT be be started until 6 hrs later due to the risk of uterine hyperstimulation
synthetic oxytocin for the induction of labour
start at a low dose
doubled every 30minutes to achieve optimal contractions
continuous CTG monitoring
infusion pumps monitored to avoid the risk of uterine hyperstimulation.
risks and complications of the induction of labour
prematurity
cord prolapse
SE: pain and discomfort, uterine hyperstimulation, fetal distress, uterine rupture
prostaglandins can can other smooth muscle stimulation= vomiting, diarrhoea, and bronchconstriction, hyperthermia
CS due to failed induction
interuterine infection with prolonged induction.
check the U&E can cause dilutional hyponatremia.
induction of labour with previous CS risk
the risk of of scar dehiscence
fetal surveillance in labour: overview
10% of CP is due to intrapartum hypoxia
the ability to withstand stress is due to fetal reserve
what is involved in fetal monitoring?
intermittent auscultation every 15 min 1 stage and every 5 minutes in the second stage
continuous CTG
antenatal risk factors that make electronic fetal monitoring that much more important
Maternal - significant medical conditions DM, previous CS, pre-eclampsia, prelabour rupture of the membranes longer than 24 hours
Fetal= IUGR, oligohydramous, abnormal doppler velocity meconium stained liquor
intrapartum risks that require EFM
oxytocin augmentation epidural analgesia intrapartum vaginal bleed pyrexia over 37.5 C fresh meconium liquor prolonged labour and abnormal FHM
what is cardiotocography?
baseline rate: mean FHR exclusion of accelerations and declarations
baseline variability: bandwidth of baseline variability between 5-25 is normal and below is reduced, raised above 25 is saltatory (nerve conduction) acceleration and deceleration (plus or minus 15 beats for more than 15 seconds.
cause of decreased baseline variability
fetal hypoxia fetal sleep cycle fetal malformation admin of drugs methyldopa, Mg SO4, tranquillisers, GA severe prematurity, fetal heart block, and fetal anomalies
fetal bradycardia
less than 110 bpm if below 100 think hypoxia
fetal tachycardia and association
160-180 bpm
maternal pyrexia, tachycardia, prematurity, and fetal acidosis
greater than 180 leads to suspect pathology
early deceleration
peak of deceleration occurs at the same time of the peak of contraction- head compression seen in 2nd stage only
late deceleration
have at least 15 second time lag between contractions may suggest acidosis if tachycardic and reduced baseline variability.
with progressive hypoxia the declarations become deeper and wider with rising baseline variability.
reassuring CTG reading
110-160
non-reassuring CTG
100-109
161-180 early declarations being present for 50% of the contractions for greater then 90 min
abnormal CTG
less than 100 or greater than 180
atypical variable declarations
pathological CTG
2 or more non-reassuring features of one or more abnormal features
maternal factors that contribute to an abnormal CTG
position: put on left lateral hypotension vaginal examination emptying bladder or bowels vomiting vasovagal episodes siting and topping up regional anaesthesia
normal fetal blood sampling results
normal PH greater than 7.25 repeat FBS if CTG is abnormal
this is used to improve the specificity go CTG in the detection of fetal hypoxia
borderline FBS
7.21-7.24 repeat within 30m uf the CTG remains pathological
abnormal FBS
Ph less than 7.2 immediate delivery!!!
mg in meconium stained liquor
associated with increased risk of perinatal mortality and morbidity
if preterm rare and associatedwith infection and chorioamnionitis
meconium aspiration syndrome
causes mechanical bloackage of the airway
acts as ac a chemical irritant causing pneumonitis
and alveolar colapse
can dele lot into secondary infection
management of meconium aspiration
grade 1 light: meconium lightly staining
grade 2 dark thick green
grade 3 think and opaque
operative vaginal delivery indications
maternal exhaustion, prolonged 2nd stage medical indications for avoiding valsalva manoeuvre- cardiac disease, HTN crisis, cerebral vascular malformation
fetal compromise and after coming head of the breech.
complications of operative vaginal delivery
forceps trauma roational forceps - spiral tears facial nerve palsy skull fracture, intracranial heamorrhage venouse assocated with scalp lacerations cephloheamtoma retinal heamorrhage
How does the vacuum extraction work and what are the complications?
works on creating negative pressure
C.I in less than 34 week gestation
compare the forceps to the vacuum
ventouse is safer for the mother, but forceps are safer for the baby.
Criteria before doing an operative vaginal delivery?
F= fully dilated cervix
O- obstruction excluded (head less than 1/5 palpable abdominally)
R- ruptured membranes and review procedure
C=consent and catheterise
Explain the procedure, epidural, and examination the genital tract
P= check presentation and position of head
S= station of the presenting part
risk factors for failed vaginal delivery
BMI greater then 30
EFW greater than 4000 g
OP position
midcavity delivery
episiotomy considered in
complicated vaginal delivery
breech, shoulder dystocia, forceps, and ventouse
if there is extensive lower genital tract trauma
when there is fetal distress.
episiotomy types
medio lateral episiotomy
complications of the episiotomy
bleeding, haematoma, pain, infection, scarring, and dyspareunia
classification of peritoneal tears
1 st degree trauma to the skin only 2- injury to perineum involving the perineal muscles 3- involves the anal sphincter a- less than 50% EAS b- greater than 50% EAS c- internal anal sphincter 4th degree is the rectal tear
third and fourth degree tears- factors associated with increased risk of anal sphincter trauma
forceps delivery, nulliparity, shoulder dystocia, second stage greater than 1hr, OP postition, midline episiotomy, birth weight greater than 4 kg, epidural anaesthesia, induction fo labour.
vaginal delivery after CS who can get it?
woman who have only one LCSC without a prior history of uterine rupture and not having a classical cs scar. he preg is in a cephalic postion at greater than 37 weeks who have a singe ton pregnancy. Tey also ca’t have a major CI like placenta previa.
With a VBAC greaterst risk
if they try a vaingal delivery and it doesn’t work and they have to go in for a CS
the absolute risk to babcy is low and pretty much the same as any other nullparous woman.
The elective repeat CS risk
there is a small increase in the risk of placenta previa and acreeta in furture preg.
