Fetal monitoring Flashcards
why is it important to monitor babies?
To reduce the rate of stillbirths in pregnancy
To detect hypoxia to prevent hypoxic ischaemic encephalopathy during labour
When is fetal monitoring carried out broadly?
During pregnancy and labour
How has the prevalence of stillbirth changed over the last century?
Dramatically declined, but is now stable at 5/1000
How are low risk women cared for during pregnancy?
community midwife and sometimes GP input
How are high risk women cared for during pregnancy?
Hospital and community
High risk patients come to antenatal clinic
All patients attend antenatal clinic. T or F?
False
Only high risk women attend antenatal clinic
What are the categories of reasons why a patient may be considered high risk?
Maternal disease Maternal situation Fetal conditions Complications in previous pregnancy Complications in current pregnancy
What are the types of maternal disease that will put a pt at high risk?
Almost anything Diabetes Hypertension Epilepsy RA Asthma ITP (can be a chronic condition in adults, autoimmune reaction against platelets, causing thrombocytopenia)
What are the effects of diabetes in pregnancy
Baby in 1st trimester
- miscarriage
Baby in 2nd trimester
- miscarriage
- stillbirth
- congenital malformation - heart defects, syringomyelia, neural tube defects (spinabifida and anencephaly)
Baby in 3rd trimester
- stillbirth
- pre-term labour and delivery
- macrosomia
- polyhydramnios
- IUGR if placental insufficiency
Effects on mother
- postpartum haemorrhage
- perineal trauma
- hyperemesis gravidarum and ketoacidosis
- UTI
- hypoglycaemia
- progression of retinopathy
- preeclampsia
- type 1 - higher dose of insulin needed
Labour
- shoulder dystocia
- stillbirth
- postpar
Neonatal
- brachial plexus injury - Erb’s palsy
- hypoxic ischaemic encephalopathy
- respiratory distress syndrome
- cerebral palsy
- death
What are the effects of hypertension in pregnancy
Fetal
- IUGR
- IUD - intrauterine death
Maternal
- worsening hypertension
- preeclapsia and eclampsia
- placental abruption
- stroke
What are the effects of epilepsy in pregnancy
Fetus
- Sodium valproate can cause spina bifida (as well as cleft lip and palate, delayed developmental milestones)
Mother
- Recurrent or worsening fits - can get injured or die
Status epilepticus is more common in pregnancy
- constant dose adjustment due to haemodilution
What are the effects of rheumatoid arthritis in pregnancy
Fetal
- pre-term birth
- SGA - small for gestational age
- Methotrexate should be stopped AT LEAST 3 MONTHS before pregnancy - reduced folate causes neural tube defects, also can cause miscarriage, facial and skull defects, heart, ribs, spine, digits defects
Maternal
- RA can get worse in pregnancy or better
What are the effects of asthma in pregnancy
Fetus
- IUGR due to inadequate placental perfusion
- premature delivery - may need to reduce pressure on mother’s lungs
Mother
- exacerbation in 3rd trimester
What are the effects of ITP in pregnancy
Fetal
- baby may also have low platelets after delivery - need platelet count after birth
- avoid instrumental delivery
- avoid fetal sampling from head
Mother
- haemorrhage, can be spontaneous, can be cerebral haemorrhage
What are the complications of previous pregnancy that may put the mother at high risk?
Previous Caesarean section 3rd or 4th degree tear previous traumatic delivery previous Pre-eclampsia previous PPH Previous small baby or preterm birth previous stillbirth
What are the different degrees of tear?
1st degree - perineal tear
2nd degree - vaginal muscle tear
3rd degree - anal sphincter tear
4th degree - rectal tear
These are cummulative, so 4th degree tear contains all of the other tears too
What are the different degrees of tear?
1st degree - perineal tear
2nd degree - vaginal muscle tear
3rd degree - anal sphincter tear
4th degree - rectal tear
These are cumulative, so 4th degree tear contains all of the other tears too
What are the complications in the current pregnancy that can make a woman high risk?
pre eclapmpsia breech presentation gestational diabetes multiple pregnancy placental previa -
What are the different types of fetal monitoring?
USS
Intermittent auscultation - hand held doppler or Pinard stethoscope
CTG
What does an USS assess in pregnancy?
Everyone gets a:
- dating scan - between 11 weeks and 13+6
- anomaly scan - 20 weeks
If high risk only or if something happens eg reduced symphysis fundal height or reduced fetal movements:
1. Growth
- head circumference (HC)
- femur diaphysis length (FL)
- abdominal circumference (AC)
- these estimates are used to estimate fetal weight (EFW)
2. Liqour volume (amniotic fluid index)
3. Umbilical artery dopplers - assess the placenta
4. fetal heart pulsations
Abnormal parameters suggest placental insufficiency or foetal problems
When is a dating scan?
between 11 weeks and 13+6 from LMP
When is the anomaly (anatomy) scan?
20 weeks
What do you measure in a dating scan?
fetal heart pulsation
crown-rump length
weeks gestation measurement
placenta - any bleeding or normal
What do you measure in the anatomy (anomaly) scan?
fetal heart pulsations
placental localisation
liqour volume
Anatomy of: - intracranium - heart - stomach - bowel - kidneys - bladder - make sure ureters are not visible - MSK - spine: longitudinal, saggital, transverse; 2 upper and lower limbs hand and feet, femur, tibia, fibula angle of foot, club foot face, cleft lip profile of baby (side of face)
What parameters does a customised growth chart take into account and what does it plot?
maternal: age, ethnicity, height, weight, parity
Previous foetal weight
Plots the symphyseal-fundal height, should stay roughly within the same centile throughout - any deviation, organise a scan
What monitoring will low risk patients get intrapartum (during labour)?
intermittent monitoring - doppler or Pinard
Listen for 1 minute after a contraction and repeat after 15 mins
What monitoring will high risk patients get intrapartum (during labour)?
Continuous monitoring with CTG
What is the normal HR of a baby
110-150bpm
More premature = higher HR
More mature = lower HR
What does a CTG measure?
Heart rate
Uterine contractions
What is the disadv of using doppler to measure HR instead of the Pinard stethoscope?
The doppler may pick up the mum’s HR and
What is the disadv of using doppler to measure HR instead of the Pinard stethoscope?
The doppler may pick up the mum’s HR and double it or can double the fetal HR
What are the advantages of using a Pinard stethoscope over CTG?
inexpensive
non-invasive
midwife can use it at home
What are the disadvantages of using a Pinard stethoscope over CTG?
variability and decelerations cannot be detected
long-term monitoring not possible
if the mother moves, you can’t hear very well with the Pinard
What are the advantages of CTG?
provides info about foetal HR AND contractions
long-term monitoring is possible
can determine variability
What are the disadvantages of CTG?
no improved outcome for low risk pregnancies - so just use it for high risk
fetal exposure to US (left handedness)
No morphological assessment of heart
ambulatory monitoring may not be possible
When do we use CTG?
Only in high risk women
Used antenatally and intrapartum
What is the normal variability?
5-25 bpm - remember that the foetal HR should vary and not stay constant
The squiggles should be crossing over the height of 1 small box
What are the aspects of assessment when using a CTG?
Dr C Bravado
Dr = Define risk
- hypertension, multiple pregnancy, diabetes, pre-eclampsia, ruptured membranes, previous stillbirth etc
C = Contractions
3-4 per 10 minutes
Bra = Baseline rate
Should be between 110-150 bpm
V = Variability
Should be 5-25 bpm
A = Accelerations
Should be at least 2 accelerations in 30 mins
D = Decelerations
No decelerations are the norm
o Early decelerations o Variable decelerations o Late decelerations
O = Overall assessment
- normal
- suspicious
- pathological
What are early decelerations, what do they mean and what would you do about them?
- not concerning
- Peak of contraction corresponds with trough of deceleration
- due to compression of the head during a uterine contraction, starts and recovers at the same time as the uterine contractions, shape is the same as the contraction - just monitor the woman
What are variable decelerations, what do they mean and what would you do about them?
- not normal
- vary in shape and timing
- due to cord compression, timing varies from the time of the contraction and the shape is different from that of the contraction, also just needs monitoring
What are late decelerations, what do they mean and what would you do about them?
- not normal,
- deceleration after contraction
- placental problem - suggests hypoxia, even after the contraction the baby’s HR has not recovered, the late deceleration, continues after the contraction has finished, identify the cause, would take fetal blood sampling if persisting, if very acidotic would deliver - so is a worrying sign
What are the normal amount of contractions and their length?
3-4 per 10 minutes
40-60 seconds
What is the normal baseline heart rate?
110-150 bpm
What is normal variability?
5-25 bpm
What is the normal amount of accelerations?
Should be at least 2 accelerations in 30 mins
How many decelerations is normal?
None, though can have early declerations in labour, but need to monitor
What does a umbilical artery doppler do?
Measures the resistance in the fetal circulation
What does an abnormal umbilical artery doppler mean?
Placental insufficiency and likely acidosis
Which means high resistance to blood flow
Which may lead to IUGR or IUD
What does an abnormal CTG mean?
Hypoxia
What are the main 4 features measured in the CTG?
Baseline rate
Variability
Accelerations
Decelerations
What is a normal CTG
All 4 features normal
What is a suspicious CTG
1 non-reassuring CTG sign
What is a pathological CTG
2 or more non-reassuring features
or
1 or more abnormal features
How would you classify the findings of a CTG?
Reassuring
Non-reassuring
Abnormal
How would you classify your overall assessment of a CTG?
Normal
Suspicious
Pathological
