Foetal Growth, compromise and surveillance Flashcards

1
Q

what is the definition for a baby that is ‘small for gestational age’

A

weight <10th centile for gestation (2.7kg if term)

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2
Q

what is the definition of IUGR

A

reduction of genetically determined weight in utero due to placental dysfunction

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3
Q

what is the difference between small for gestational age and IUGR

A

SGA is a statistical thing (<10th centile) whereas IUGR is more personal to the foetus’ genetic potential, for example a baby may be born as 3kg (>10th centile) but was supposed to grow to 4kg, therefore being growth restricted but not small for gestational age

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4
Q

what is the defnition for foetal compromise

A

Chronic condition describing a situation where the optimum situation for growth and neurological development is not achieved in utero

Usually due to a poor nutrient transfer through the placenta

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5
Q

what are some causes of foetal compromise

A

IUGR

Prolonged pregnancy

Gestational diabetes

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6
Q

when doing a maternal uterine doppler what is the normal/abnormal reading and what does an abnormal reading mean

A

low resistance flow = normal

abnormal waveform is bad and flow reversal is worst

abnormal readings indicate potential complications in the 3rd trimester - IUGR, placental abruption, preeclampsia

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7
Q

what gestational age is a maternal uterine doppler reading most sensitive

A

20-23 weeks

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8
Q

what are methods of foetal growth surveillance

A

USS

Doppler

CTG

Kick chart

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9
Q

what are the advantages of using USS to determine between constitutional growth delay and IUGR

A

Allows identification of the pattern of smallness – abdomen stops enlarging before head so abdominal circumference growth reduction rate >30% is indicative of IUGR

Serial scans show not only the rate of growth, but also allows more customisation for the foetuses personal growth compared to the gestational averages

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10
Q

how is flow resistance classified in maternal uterine artery dopplers

A

High-end diastolic flow

Absent end-diastolic flow

Reversed end-diastolic flow

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11
Q

what kind of pregnancies is maternal uterine doppler most useful for when detecting growth restriction

A

high risk pregnancies as it detects abnormalities before CTG

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12
Q

what gestational age does maternal uterine doppler become less effective on its own

A

34 weeks

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13
Q

what are abnormal features on a CTG

A

Heart rate outside of 110-160

decelerations in heart rate

decreased variability (<5 bpm)

absent accelerations

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14
Q

what gestational age can CTGs be used

A

26 weeks

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15
Q

what does reduced foetal movement indicate

A

imminent foetal death

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16
Q

what are causes of constitutional reduction in size

A

Low maternal height and weight

Nulliparity

Asian ethnic group

Female foetal gender

17
Q

what are pathological causes for reduced foetal size

A

Pre-existing maternal disease

Maternal complications

Multiple pregnancy

Smoking

Drug usage

Infections – CMV

Extreme exercise

Malnutrition

Congenital abnormalities

18
Q

what are complications for a foetus being small for gestational age

A

Stillbirth – 50% of unclassified still births are SGA/IUGR

Foetal distress

NICU admission

Long term handicap

Preterm delivery more common

Risk of pre-eclampsia is higher

19
Q

how do you formally diagnose small for gestational age/IUGR and what are the next investigations

A

IUGR
Reduction of growth of symphyseal fundal height on serial measurement
USS detected >30% reduction in abdominal growth velocity + doppler umbilical artery flow reversal/absent flow
If <34 weeks check BP and urine for pre-eclampsia as it commonly co-exists with IUGR
Oligohydramnios is also often seen

SGA 
Found on USS  
Investigations to determine cause  
Repeated Anomaly scan  
CMV testing 
Chromosomal abnormality testing
20
Q

how do you manage a foetus that is small for gestational age

A

Growth is checked with 2-3 weekly USS scans

If 0-2nd centile weight – delivery at 37 weeks

If 3-9th centile – wait until 40/41 weeks to allow labour to be spontaneous

21
Q

how do you manage a foetus with IUGR

A

<34 weeks
Aim is to prevent in utero demise and protect neurological function
Needs to be >500g and >25-26 weeks for intervention
Abnormal dopplers = twice-weekly monitoring
Admit + give steroids if AEDF
>32 weeks = C-section
<32 weeks = daily CTGs, only deliver if abnormality found
Delivery <34 weeks = immediate maternal magnesium sulphate

34-37 weeks
Deferred delivery if no abnormal doppler
Delivery may be via induction or C-section if CTG is abnormal

> 37 weeks
Delivery is induction or C-section if abnormal CTGs

22
Q

what’s the definition of a stillbirth

A

delivery after 24 weeks with no signs of life

23
Q

what is the risk of stillbirth if a patient has already had one

A

1 in 40-66 (3-5x from 1 in 200)

24
Q

what are causes of foetal stillbirth

A
IUGR 
Smoking 
Multiple pregnancy  
Unknown – often due to mechanism behind IUGR 
Foetal chromosomal abnormalities  
Pregnancy related maternal disease  
Infection  
Placental abruption  
Intrapartum hypoxia 

Rare
Foetal exsanguination (severe loss of blood)
Fatty liver
Cholestasis

25
Q

what is the definition of a prolonged pregnancy

A

> 42 weeks

26
Q

what is prolonged pregnancy more common in

A

Previous prolonged pregnancy

Nulliparous women

27
Q

what % of pregnancies reach 42 weeks

A

6%

28
Q

what are complications of prolonged pregnancy

A

Meconium passage

Foetal distress

Neonatal illness

Encephalopathy

29
Q

what is the management of potential prolonged pregnancy

A

balance risk of obstetric management vs the risks of prolonged birth

41-42 weeks induction is preferred

A cervical sweep is usually performed at 40-41 weeks