GOSH revision Flashcards
normal variation in a CTG
5bpm or more
3 steps to assess contractions
- frequency (count number in 10 minute period)
- duration: how long do they last
- intensity (NOT from CTG - palpate the uterus)
5 causes of foetal tachycardia (>160)
- foetal hypoxia
- chorioamnionitis
- hyperthyroidism
- foetal/maternal anaemia
- foetal tachyarrhythmia
5 causes of foetal bradycardia (<100)
- prolonged cord compression
- cord prolapse
- epidural/spinal anaesthesia
- maternal seizure
- rapid foetal descent
what indicates severe hypoxia in a foetus
severe prolonged bradycardia (80bpm for >3 mins)
non-reassuring variability is
- <5bpm for 30-50 mins
- >25bpm for 15-25 mins
abnormal variability is
- <5bpm for >50 mins
- >25bpm for >25 mins
5 causes of reduced variability
- sleeping (<40 mins)
- foetal acidosis due to hypoxia - more likely if late decelerations
- drugs (opiates, benzos, methyldopa, mag sulphate)
- prematurity
- congenital heart abnormalities
typical vs atypical deceleration
typical = <60 seconds for <60bpm - typical ones also have shouldering (good - foetus is adapting to reduced blood flow and is not yet hypoxic)
atypical = >60 seconds OR >60bpm drop in HR
3 causes of late decelerations
- maternal hypotension
- pre-eclampsia
- uterine hyperstimulation
hypoxic and acidotic :(
what does a sinusoidal pattern indicate
severe foetal hypoxia/severe foetal anaemia/foetal or maternal haemorrhage
5 things to do if worried about CTG
- change maternal position to left lateral (increase CO)
- give fluids if dehydrated
- foetal scalp electrode - if increases HR = good
- foetal blood sample for pH testing
- delivery
when should foetal blood sample be done
if worried about CTG and delivery not imminent - must be >3cm dilated and should take 2 samples
pH normal = >7.25, <7.2 = v bad and needs delivery
difference between parity a and parity b
- parity a = number of pregnancies where foetus reaches 24 weeks (includes stillbirths)
- parity b = number of pregnancy losses before 24 weeks
advice given in the booking visit
- FA supplementation for 12 weeks
- food hygiene (no raw milk/cheese)
- stop smoking, alcohol,. drugs, do exercise, healthy diet
- antenatal screening advice
purpose of dating scan
- confirm viability of pregnancy
- ensure gestational age is correct and reduce need for IOL
- aid detection of lethal abnormalities
- detect multiple pregnancies and assess chorionicity
when is combined test carried out
11-13+6 weeks (at same time as dating scan)
3 results of combined test indicating Down’s syndrome
- thickened nuchal fold (>35mm) - scan
- raised hCG - blood test
- lowered PAPP-A - blood test
when and what does the quadruple test
14-17 weeks if too late to do combined test
- AFP
- hCG
- oestriol
- inhibin A
what is a positive result of combined/quadruple and what to do after
> 1/150 chance
CVS at 11-14 weeks
amniocentesis at 15 weeks
3 possible NIPT test results a woman could get
- positive = invasive test needed to confirm
- negative = v likely not
- inconclusive (4%) = test repeated
how is gestational age measured at 10-12 weeks at dating scan
if BEFORE 13 WEEKS = foetal CRL
after 13 weeks = biparietal diameter, head circumference, femur length
what can raised AFP indicate
- open NTD
- exomphalos
- posterior urethral valves
- GI obstruction
- teratomas
IUGR, preterm, placental abruption, 3rd trimester death
what is PAPP-A and what do low levels indicate
glycoprotein made by placenta - low levels in 1st trimester indicate:
- trisomy 13/18/21
- pre-eclampsia
- IUGR
- preterm delivery