Assessing fetal welfare Flashcards
Frequency of auscultation
Low risk - Active phase every 15-30 minutes
- Second stage every 5 minutes (or after every contraction)
High risk - Active phase every 15 minutes
- Second stage every 5 minutes (or after contraction)
What other moments in labour do you need to do intermittent ausculatation?
After VE
After SROM/ARM
After administration of meds
Abnormal uterus activity
Where is fetal heart best heard
anterior shoulder
How to do IA
Listen for long time when first done
When listening in listen for 1 minute
Get maternal pulse at same time
When should IA in low risk women be converted to CEFM
thick mec (consider for thin)
abnormality of IA
Bleeding
Synto
Womens reuest
Pyrexia
Maternal indications for continuous CTG
Maternal morbidity: diabetes/pre-eclampsia/HTN/hypothyroidism/anaemia
High BMI
Previous CS
APH
Fetal indications for CEFM
Multiple pregnancy
IUGR/SGA
Oligohydramnios
Polyhydramnios
Rh isoimmunisation
Abnormal dopplers
Gestation >42 weeks
Prematurity <37 weeks
Breech
Labour indications for CEFM
Pyrexia - 2x measurements >37.5 or one >38.0
Thick mec (consider for thin)
Abnormal uterine contractions
Blood stained liquour
Syntocinon
Epidural
Abnormal IA
Induced/augmented labour
PROM >24h
Prolonged labour
What is tachysystole
> 5 contractions in 10 minutes
What is hypertonus
contracteions >2 min or <60 seconds between
How do you assess a change in baseline fetal heart rate
needs to be 10 minutes or more
What is mild bradycardia associated with
post-dates and OP babies
What does persistent fetal tachy >180 suggest
chorio
What about a transient tachycardia after an acute hypoxic episode
Physiological response due to catecholamine release
What effect can steroids have on the CTG
Reduced variability for 24h
What is the significance of shouldering
may indicate partial cord compression. Reassuring sign in comparison to is they disppear.
Why is there decellerations in second stage
head compression causing vagal stimulation –> parasympathetic.
What if there are accelerations in second stage
MAKE SURE NOT MATERNAL
What are early decellerations
Occur with head compression usually during SLEEP cycle.
Mirror and finish by the time contraction is over
They are benign if all other features of CTG are normal.
Only occur when woman is 4-8cm dilated as beyond this the head compression is more significant
Seldom go below 100bpm. Do not decrease more than 60 from baseline
Factors that make variables complicated
rising baseline
smooth over shoot after decel
slow to get back to baseline
rop >60 bpm
reduced variability
loss of shouldering
Define late decelleration
Begins after the onset of contraction. Madir is at least 20 seconds after peak of contraction and ends after the end of contraction
Pathophysiology of late decellerations
In healthy babies that are centrally oxygenated a contraction will limit the gas exchange within the intervillous space - but the babies have been able to spare the important organs so heart rate can go back up no problem. They have some back up O2 because the placenta is giving them loads of O2 in between contractions.
In inhealthy babies that are already hypoxic, the HR drops after the contraction has started because the baby has no O2. This is because there is utero-placental insufficiency. It is only when the contraction stops that the baby can get some more O2 and gradually raise the heartrate.
Contraindications to FBS
Maternal infection - chorio/HIV/hepB
Fetal compromise significant on CTG
Face presentation
<34 weeks
Fetal bleeding disorders
