management of labour + delivery Flashcards
(37 cards)
what are the indications for and complications of c-section?
indications: Main categories are fetal compromise, repeat CS, failure to progress in labour, breech.
emergency within 30 mins “category 1” = abruption, cord prolapse, scar rupture, prolonged fetal brady, scalp pH <7.2,
urgent = failed progress+ abnormal CTG
scheduled= severe pre-eclampsi, IUGR with poor fetal function tests, failed induction of labour
elective= placenta previa (minor/ major), breech baby (Cephalic version should usually be attempted first before CS offered), women with uncontrolled HIV, mum has primary HSV in genital tract, twins with non-cephalic first twin presentation
what are complications of c section?
uterocervical laceration (5-10%)
blood loss > 1L (7-9%)
bladder laceration (0.5-0.8%)
blood transfusion (2-3%)
hysterectomy (0.2%)
DVT/ PE risk, accidental cut to baby + resp distress, infection.
complicartions in future pregnancies: increased risk of placenta percreta/ accreta, placenta previa.
What is the common type of c-section and why?
Pfannensteil incision 2 cm above Pubic Symphysis, horizontal cut to access lower segment of uterus. lower chance of adhesion formation, decreased blood loss bc less well perfused, lower incidence of scar dehiscence in later pregnancy. Good cosmetic outcome.
T/ J incision = lower segment but with a slight vertical section bc fetal malposition. If this has been done previously, c-section will need to be done for subsequent pregnancies.
Classical CS = vertical incision in upper segment of uterus but rarely performed. Done if prem <28weeker or placenta previa/ accreta to not disturb placenta in lower segment. If this is done, elective c section will need to be repeated due to risk of scar dehiscence.
what anaesthesia is used in c-section and in normal labour and what are their indications?
c-section: SPINAL safer and better outcomes for mum and neonate than GA. Hypotension is a common SE therefore ephedrine/ phenylephrine (bc spinal is symp blockade) is on hand + volume pre-load with colloid is set up to mitigate this + lateral tilt of bed.
what are the indications of established labour? Outline the stages of labour?
“Established Labour” = regular painful contractions accompanying dilatation + effacement of the cervix.
Other features (but not necessary for labour to have begun)- descent of presenting part e.g. head, rupture of membranes, “show” - cervical mucus plug +/- blood, ‘nesting’- desire to get home ready for baby, n/v/d.
Stage 1: Initiation of labour to full cervical dilatation (10cm)
- subdivided into latent + active (latent is from 0-3/4cm dilated + reg contractions (3-4/ 10 mins). [variable length]
Stage 2: Full cervical dilatation to delivery of the fetus [1-2hours]
Stage 3: Delivery of Fetus to delivery of Placenta + memb + control of bleeding. [physiologically 1 hour]
what is involved in the inital assessment of mum + baby?
mum’s obs: BP, urine, HR, temp
ask about pain + fetal movements
ask about length, strength + freq of contractions
ask about ROM (+ any colour to it- green meconium), bleeding, show.
palpate abdomen record LPP and engagement
auscultate fetal HR for 1 min immediately follow contraction.
offer vaginal exam if appears to be in established labour.
what are some maternal + fetal indications for transfer to obs-led care?
Mum: HR >120 twice at least 30m apart BP >160 SBP or >110 DBP once, or >140SBP >90DBP twice at least 30 mins apart Temp >38 once, or >37.5 twice at least 30 mins apart any vaginal blood loss except show ROM >24h before established labour significant meconium > pain than expected in contractions Baby: abnormal presentation e.g. cord transverse / oblique lie high 4-5/5 palpable head in nullip suspected fetal growth restrict/ macrosomia Fetal HR <110 or >160 deceleration heard on intermittent auscultation reduced fetal movements last 24h anhydramnios or polyhydramnios
What are normal Fetal values?
HR 110-160
scalp pH
what monitoring should be provided during labour?
In Stage 1, Fetal HR (if cephalic presentation, no twins, >37weeks and no problems): every 15 minutes for at least 1 minute immediately after contraction (so that any decelerations heard indicate pathology rather than a normal response to contraction). if any abnormality detected, they are moved onto continuous. In Stage 2, auscultate every 5 mins.
Maternal Pulse: hourly
4 hourly temp + BP (hourly if in bath + temp of bath)
Urine Output
half‑hourly documentation of the frequency of contractions
how does the head move during delivery?
- enters the pelvic inlet in occipito-transverse position (occiput turned towards the lateral pelvis) bc transverse diameter is bigger than AP
- descends further into pelvis and head flexes onto chest
- rotation 90 degrees to occipital anterior, occiput facing pubic symphysis, face facing sacrum bc AP diameter is bigger than transverse
- further descent
- extension to deliver baby pops head up as though coming up from beneath water
- “restitution” where baby rotates back 90 degrees to occipito transverse position to allow shoulders passage
what are the terms used to describe baby’s orientation etc in mum?
lie: transverse, longitudinal, oblique
presentation: part of fetus occupying lower segment of pelvis ie cephalic or breech (butt first)
position: of back of head in relation to pelvis, occipito- anterior, -posterior, - transverse
attitude: degree of flexion of baby’s head.
what causes the physiological initiation of labour?
Progesterone inhibits labour by causing uterine quiescence (prod by placenta), preventing PG + oxytocin release. Levels of P drop as labour approaches.
Prostaglandin reduces cervical resistance (causing dilatation + effacement) and increases oxytocin release. PGs cause uterine contractions.
oxytocin is released from post pituitary gland. Maintain contractions of uterus + useful for delivery of placenta (+ prevent post partum haemorrhage) + stim. milk ejection.
Contractions cause sign reduced blood delivery to the foetus and the space between these enable baby to recover from this hypoxic stress.
how can labour be delayed? What else should be given if fetus is preterm?
Tocolytics.
Steroids.
ADD TO
what are the three important factors determining success of normal birth?
Power: Regular strong contractions of mother’s uterus
Passenger: Correct position, adequately flexed, not too large
Passage: adequate size + shape
describe the shape of the pelvis at different depths.
Inlet: transverse diameter > AP diameter
Middle: circle
Outlet: AP diameter > transverse diameter
what is the obstetric conjugate?
distance from pubic symphysis to the sacral promontory, usually ~ 10cm
what are the ischial spines helpful for during delivery?
locating the pudendal nerve
a reference point for measuring the “station” of the presenting part. Above the spine = - figure, below is + figure to indicate how close mum is to deliver
what is the definition of shoulder dystocia?
following the passage of the fetal head under the pubic symphysis during vaginal delivery, the anterior shoulder attempts to follow. Shoulder dystocia means the (anterior usually) shoulder impacts on the pubic symphysis or sacral promontory. This delivery will require additional obstetric manoeuvres to deliver the fetus after the head has delivered and gentle traction has failed.
What are the complications (mum + baby) of shoulder dystocia? What are the RF for shoulder dystocia?
Mum: post-partum haemorrhage (11%), perineal tear 3-4 degree (4%)
Baby: Brachial plexus injury,
Maternal DM (best evidence for), Other RF:
macrosomia, maternal BMI >30, induction of labour, previous shoulder dystocia, prolonged stage 1/2 labour, assisted vaginal delivery, oxytocin augmentation.
Maternal DM benefit of inducing labour to reduce the risk of shoulder dystocia.
what is the relevance of the pubic arch in deliverY? Where is it located?
It denotes the upside down v shape below the p. symphysis and if it is too narrow It makes vaginal delivery difficult/ imposs. Arch narrowness can be determined by examining how many finger breadths can be passed under the arch (should be at least 3).
what does active management of stage 3 involve?
oxytocin (syntocinon) is given to shorten phase reducing blood loss. (syntometrine used to be given but gives lots of nausea + cannot be used in HT).
What are the basics of interpreting CTG’s?
DR C BRAVADO
Determine the Risk: preterm? previous obs problems, any issues e.g. DM
C: Contractions - length, strength, timing >5/ 10 mins bad
Br: Baseline rate - line of best fit (HR) does this fit baby? TERM normal 120-160, Abnormal <100 or >180. Preterm expect higher baseline HR bc less developed parasympathetic system.
A: Accelerations indicate somatic system intact (increase from baseline rate of >15bpm or >15seconds)
Va: Variability- if baseline is very reactive this is healthy.
Loss of variability early sign of problem. Due to lack of para + symp action therefore not regulating HR well and no longer compensating for hypoxia. Usually HR increases bc parasympathetic is overriden by sympathetic. This precedes big increase HR and then drop off before death.
D: Decelerations - at least 15bpm, lasting for at least 15 seconds. Can be early, variable or late.
O: Overall conclusions?
What are normal responses in fetuses to contractions?
rapid drop in HR before returning to normal rate (deceleration), this is a physiol rxn to stress to allow ventricles to fill adequately and to reduce O2 consumption.
This is normal at the start of contractions, associated with head compression, raised ICP, reflex vagal nerve stimulation (BaroR sense increased BP) causing bradycardia.
Produce normal “early” decelerations that are a mirror image of the contractions of the uterus, returning to baseline as contraction finishes.
what indicates a healthy fetus on CTG?
Somatic activities (increase HR) - ie accelerations/ upward deflections. If a fetus is unwell, it will decrease movements to conserve energy – early sign of a problem.
Variability in HR shows that the parasympathetic + sympathetic are both working and balancing each other out.
Remember fetus preserves the heart before the head!
