what are maternal indications for recommending continuous CTG monitoring?
- 1. previous CS
- 2. PET
- 3. DM
- 4. APH
- 5. other maternal medical disease
what are fettle indications for recommending continuous CTG monitoring?
- 1. IUGR
- 2. prematurity
- 3. oligohydramnios
- 4. abnormal doppler artery studies
- 5. multiple pregnancy
- 6. breech presentation
what are intrapartum indications for recommending continuous CTG monitoring?
- 1. meconium stained liquor
- 2. vaginal bleeding in labour
- 3. use of oxytocin
- 4. epidural analgesia
- 5. maternal pyrexia
- 6. post term pregnancy
- 7. prolonged ROM > 24 hours
- 8. induced labour
what should the normal baseline FHR be?
how is the baseline of a preterm different to term baby?
what is fetal tachycardia associated with?
- fetal infection
- fettle hypoxia - if in conjunction with other abnormalities
what does a steep sustained deterioration in FHR suggest?
acute fettle distress
what is normal variability in FHR?
> 5 bpm
what are exceptions to variability and how long do they last?
- fettle sleep
- less than 45 minutes
what does prolonged reduced variability, particularly with other abnormal features suggest?
what constitutes as an acceleration of FHR and what does it show with contractions show?
- increase in FHR from baseline by >15bpm and lasting 15s or more
what is a deceleration defined as?
- drop in FHR by > 15bpm from baseline
- lasting > 15 seconds
what is an early deceleration ? what does it it indicate?
- synchronous with a contraction as a normal response to head compression
- so usually benign
what is an late deceleration ? what does it it indicate?
- FHR begins to fall during the contraction and its trough is > 20seconds after the peak of the contraction, returns to baseline after the contraction
- suggests fettle hypoxia
what is a variable deceleration?
when the timing of the slowing of the FHR in relation to the contraction VARIES and can occur in isolation
what does variable deceleration classically reflect?
- cord compression
- which can ultimately cause hypoxia
if you suspect hypoxia eg due to late decelerations, what should be done to confirm it?
fettle blood sample: scalp pH
what is a sinusoidal pattern on CTG?
- regular OSCILLATION of the baseline,
- with ABSENT variability
how long does sinusoidal pattern last?
- at least 10 minutes
- amplitude: 5-15bpm above and below the baseline
what is a normal CTG?
- baseline normal
- variability are normal
- there are accelerations
- no decelerations
what is a SUSPICIOUS CTG?
- one feature is non-reassuring, the others are reassuring
- eg baseline to high or low
- variability too little or for too little time
- decals present: early or variable (not late as that is abnormal)
- no accels
what is a PATHOLOGICAL CTG?
- 2 or more features are non-reassuring
- or more than one is abnormal
what is the mean principle of monitoring during labour?
detect fettle hypoxia, so prevent acidosis and cell damage
what are causes of acute fettle hypoxia - 4
- 1. uterine HYPERSTIMULATION
- 2. placental ABRUPTION
- 3. cord COMPRESSION
- 4. sudden maternal HYPOTENSION eg insertion of regional anaesthesia
what thing during pregnancy is a risk factor for hypoxia during labour?
chronic uteroplacental insufficiency eg due to PET
apart from FHR, what is CTG useful for?
FREQUENCY of maternal uterine contractions
why is strength and length of each contraction not checked by CTG?
- depends on positioning of monitor on maternal abdomen
- thickness of maternal abdominal wall
what effect can epidural analgesia have on fetes?
fettle bradycardia due to maternal hypotension and less blood flow to uterus
if CTG is found to be pathological, what should the next Ix be?
fettle blood sampling
if FBS is abnormal, what is main aim?
name 3 contraindicaitons to FBS
- 1. maternal HIV, Hep B, Herpes simplex
- 2. fetal bleeding disorder: haemophilia or thrombocytopenia
- 3. prematurity < 34 weeks