labour Flashcards
reasons to induce
PROM, post dates, maternal health problem, FGR
absolute contraindications to induction
Classical C section scar, transverse lie, active herpes, vasa praecia
how much vaginal prostaglandins are given in IoL
1 dose over 24 hours
how does a membrane sweep work
rub finger against fetal membrane and aim to release natural prostaglandins
complications of IoL
failure, uterine hyperstimulation, cord prolapse, pain, increase rate of further intervention
when is vaginal delivery allowed with HIV
when viral load <50 at 36 weeks
(and then baby is given AVT when born)
indications for CTG monitoring
-induction
-conditions like HTN / preeclampsia / GDM
-smoking
-vaginal blood loss
-previous C section
-IUGR
-malposiiton
how to interpret CTG
DR
Contractions
Baseline Rate (110-160)
Accelerations (>15bpm for >15s)
Variability (5-25)
Decelerations
Overall impression
cause for baseline bradycardia on CTG
-maternal beta blockers
-prolonged cord compression
cause for baseline tachycardia on CTG
-maternal infection
-prematurity
causes for reduced variability on CTG
fetal sleeping (this should not last for more than 40 minutes), fetal acidosis, drugs like benzes
why do you get decelerations on CTG
fetal response to hypoxic stress to preserve myocardial oxygenation
what should decelerations be if they are seen on CTG
early or variable (meaning they don’t relate to the contractions but should have shoulders of decelerations)
what does a late deceleration indicate
that there is no recovery after contraction (shows placental insufficiency)
what does a sinusoidal patter show on CTG
severe fetal hypoxia, severe fetal anaemia, maternal haemorrhage
a deceleration for how long is ABNORMAL
3 minutes
if the CTG is non resassuring, what might be done
FBS to look for acidosis and lactate
what are the 3 categories for overall impression on CTG
-reassurig.
-non reassuring
-abnormal
RF for breech baby
-prematurity
-congenital abnormality
-uterine malformation like fibroids
-polyhydraminos
success of VBAC
70%
risk of scar rupture in VBAC
1/200
requisites for VBAC
one/two previous CS, birth in hospital, no previous uterine rupture
stepwise Mx of shoulder dystocia
1) mcroberts manoeuvre (+suprapubic pressure)
2) woodscrew
3) zavanelli / symphysiotomy
what can a ventouse delivery cause
cephalohaematoma
does a ventouse/forceps cause a create risk to mum
forceps
contraindications to assisted vaginal delivery
breech, incompletely dilated cervix, true cephalon-pelvic distortion
Cat 1 section should be done in
30 mins
Cat 2 section should be done in
75 mins
Cat 3 section
scheduled as early delivery required but not urgent eg breech, IUGR, failed induction
when is an elective C section done
39 weeks to prevent TTN
why is metoclopramide used in C section
prevent aspiration of gastric contents
what layers are cut through in a C section
skin
Subcut
Fascia (superficiale and deep)
rectus sheath
rectus muscle
Parietal peritoneum
Visceral peritoneum
uterus
indication for a classical C section scar
structural abnormalities of the uterus
where does a second vs a third degree tear need to be repaired
second degree in ward (anal sphincter in tact)
third degree in theatre
fourth degree in theatre (and need post op laxatives and abx as the rectal mucosa involved)
what are the borders of the pelvic inlet?
iliopectineal line, pubic symphysis, sacral promontory
what are the borders of the pelvic outlet
ischial tuberosity, tip of coccyx, pubic arch
why does the head rotate in labour
the transverse diameter is widest at the pelvis inlet, but the AP diameter becomes widest at the outlet
what are the cardinal movements of labour
1) descent and flexion (head descends in the ROT or LOT - left occiput transverse)
2) internal rotation to the occiput anterior position
3) extension of the presenting part
4) external rotation restitution
5) deliver of shoulders by downward traction to deliver the anterior should and then upwards traction
can a baby deliver in the occiput posterior position
yes but may be more painful, will get an early urge to push and may need forceps
what is engagement
when the largest diameter of the fetal head fits into the largest diameter of the maternal pelvis
what is the active vs physiological mx of the third stage of labour
active - IM oxytocin given, cord is clamped after 1-5 minutes and the placenta pulled out after it has separated
physiological - cord is clamped and cut once it has stopped pulsing and the women then pushes the placenta out with contractions
how is a mums progress in labour monitored
on a partogram (use HR, cervical dilation, station, contractions, blood pressure, drugs used
side effects of pethidine or diamorphine (IM or IV)
cause drowsiness, nausea, vomiting
why do NSAIDs have to be avoided in pregnancy
premature closure of the PDA and resistant pulmonary hypertension in the newborn
