[31] Small for Gestational Age Flashcards Preview

A - MSRA Obstetrics [16] > [31] Small for Gestational Age > Flashcards

Flashcards in [31] Small for Gestational Age Deck (47)
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1
Q

What is meant by small for gestational age (SGA)?

A

An infant with a birth weight <10th centile for its gestational age

2
Q

What is severe SGA?

A

Birth weight <3rd centile

3
Q

What is fetal SGA?

A

An EFW or abdominal circumference <10th centile

4
Q

What is severe fetal SGA?

A

EFW or AC <3rd centile

5
Q

What is fetal growth restriction?

A

When a pathological process has restricted genetic growth potential

6
Q

How can fetal growth restriction present?

A

Fetal compromise, including reduced liquor volume or abnormal Doppler studies

7
Q

What is low birth weight?

A

An infant born with birth weight <2500g

8
Q

What can the pathophysiology of SGA be divided into?

A
  • Constitutionally small
  • Placenta mediated growth restriction
  • Non-placenta mediated growth restriction
9
Q

What % of SGA foetuses/infants are constitutionally small?

A

50-70%

10
Q

How are constitutionally small foetuses identified?

A

Small size at all stages, but growth following the centiles

11
Q

What is the pathology in constitutionally small foetuses?

A

No pathology is present

12
Q

What are the contributing factors for constitutionally small foetuses?

A
  • Ethnicity
  • Sex
  • Parental height
13
Q

How is placental mediated growth restriction identified?

A

Growth is normal initially, but slows in utero

14
Q

What are the maternal factors that can result in placental insufficiency?

A
  • Low pre-pregnancy weight
  • Substance abuse
  • Autoimmune disease
  • Renal disease
  • Diabetes
  • Chronic hypertension
15
Q

What can cause non-placenta mediated growth restriction?

A
  • Chromosomal or structural abnormality
  • Error in metabolism
  • Fetal infection
16
Q

When should women be assessed for risk factors for SGA?

A

At booking, and again in 20 weeks

17
Q

What are the major risk factors for SGA?

A
  • Maternal age >40
  • Smoker 11 or more per day
  • Previous SGA baby
  • Maternal/paternal SGA
  • Previous stillbirth
  • Cocaine use
  • Daily vigorous exercise
  • Maternal disease
  • Heavy bleeding
  • Low PAPP-A
18
Q

What maternal disease is a risk factor for SGA?

A
  • Chronic hypertension
  • Renal impairment
  • Diabetes with vascular disease
  • Anti-phospholipid syndrome
19
Q

What is PAPP-A?

A

Pregnancy associated plasma protein

20
Q

What are the minor risk factors for SGA?

A
  • Maternal age 35 or over
  • Smoker 1-10/day
  • Nulliparity
  • BMI <20 or 25-34.9
  • IVF singleton
  • Previous pre-eclampsia
  • Pregnancy interval <6 or >60 months
  • Low fruit intake pre-pregnancy
21
Q

What is the role of ultrasound in SGA?

A

It is used for the diagnosis and surveillance of a SGA fetus

22
Q

What ultrasound biometrics can be used in the assessment of fetal size?

A
  • EFW

- AC

23
Q

What is done with ultrasound biometrics to help determine fetal growth?

A

They are plotted on customised centile charts

24
Q

What do customised centile charts take into account?

A
  • Maternal characteristics
  • Gestational age
  • Sex
25
Q

What maternal characteristics are taken into account on customised centile charts?

A
  • Height
  • Weight
  • Ethnicity
  • Parity
26
Q

What ratio is important when assessing SGA?

A

Head circumference to AC

27
Q

Why is the head circumference to AC ratio important in SGA?

A

A symmetrically small fetus is more likely to be constitutionally small, whereas an asymmetrically small fetus is more likely to be caused by placental insufficiency

28
Q

What other ultrasound finding might be present in placental insufficiency?

A

Reduced amniotic fluid volume

29
Q

Why might there be a reduced amniotic fluid volume with placental insufficiency?

A

Placental insufficiency can result in impaired kidney function, which can cause reduced amniotic fluid volume

30
Q

What investigations may be appropriate in SGA?

A
  • Detailed fetal anatomical survey
  • Uterine artery Doppler
  • Karyotyping
  • Screening for infections
31
Q

What infections should be screened for in SGA?

A
  • CMV
  • Toxoplasmosis
  • Syphilis
  • Malaria
32
Q

How can SGA be prevented?

A
  • Modification of risk factors

- Anti-platelet agents

33
Q

Give 2 examples of how risk factors can be modified to prevent SGA?

A
  • Promoting smoking cessation

- Optimising maternal disease

34
Q

In whom might anti-platelet agents be effective at preventing SGA?

A

Women at high risk of pre-eclampsia

35
Q

When should anti-platelet agents be started in women at high risk of pre-eclampsia?

A

On or before 16 weeks of pregnancy

36
Q

What is the primary surveillance tool in a SGA fetus?

A

Uterine artery doppler

37
Q

What should be done if the uterine artery doppler is normal in a SGA fetus?

A

Repeat every 14 days

38
Q

What should be done if the uterine artery doppler is abnormal in SGA fetus?

A

Repeat more frequently, or consider delivery

39
Q

What other tests may be useful in the surveillance of a SGA fetus?

A
  • Symphysis fundal height (SFH)
  • Middle cerebral artery (MCA) Doppler
  • Ductus venosus doppler
  • Cardiotocography
  • Amniotic fluid volume
40
Q

What should be given in SGA if delivery is being considered between 24 and 35+6 weeks gestation?

A

A single course of antenatal steroids

41
Q

What should be done if the fetus is <37 weeks and there is absent/reverse end-diastolic flow on Doppler?

A

Offer C-section

42
Q

What should be done if the fetus is SGA and 37 weeks?

A

Offer induction

43
Q

What is induction for SGA fetus associated with?

A

High rate of C-section

44
Q

What is required when inducing someone for SGA fetus?

A

Continuous fetal heart rate monitoring from onset of contractions

45
Q

What are the neonatal complications of SGA?

A
  • Birth asphyxia
  • Meconium aspiration
  • Hypothermia
  • Hypo or hyperglycamia
  • Polycythaemia
  • Retinopathy of prematurity
  • Persistent pulmonary hypertension
  • Pulmonary haemorrhage
  • Necrotising enterocolitis
46
Q

What are the long-term complications of SGA?

A
  • Cerebral palsy
  • Type 2 diabetes
  • Obesity
  • Hypertension
  • Precocious puberty
  • Behavioural problems
  • Depression
  • Alzheimer’s
  • Cancer
47
Q

What cancers are more common in people that were SGA at birth?

A
  • Breast
  • Ovarian
  • Colon
  • Lung
  • Blood

Decks in A - MSRA Obstetrics [16] Class (61):