Management of

Small For Gestational Age

RCOG,2013

Aboubakr Elnashar

Benha university Hospital, Egypt

Definitions

Prevention

I. Screening

II.Diagnosis

III.Investigations

IV.Surveillance

V.Delivery

Definitions SGA

EFW or AC <10th centile

EFW or AC <3rd centile: Severe

60%:

constitutionally small, with fetal growth appropriate

for maternal size and ethnicity.

FGR

Pathological restriction of the genetic growth

potential.

±Manifest evidence of fetal compromise:

abnormal Doppler studies, reduced liquor volume.

Not synonymous with SGA.

Some, but not all, FGR are SGA

Higher in severe SGA

LBW

An infant with a birth weight < 2500 g.

Population centiles:

Customised centiles:

Maternal: height, weight, parity and ethnic

group

Foetal: sex

better sensitivities for identifying FGR lower false-positive rates predictive of poor perinatal events (Grade B, RCOG 2013)

Prevention

1. Smoking cessation

2. Antithrombotic agents

Promising in high risk women.

insufficient evidence, especially concerning

serious adverse effects, to recommend its use.

3. Antiplatelet agents

Effective in preventing SGA in women at high risk

of preeclampsia

At or before 16 w

I. Screening 1. At booking for risk

factors

1 major risk factor:

serial US for

fetal size and

Um AD at 26-28 W

Fetal echogenic bowel

:Serial US

fetal size and

Um A D at 26-28 W

A low level (< 0.415 MoM) of the 1st trimester

marker PAPP–A should be considered a major

risk factor for SGA.

2nd trimester DS markers have limited

predictive accuracy for a SGA:

AFP: (> 2.5 MoM or < 0.25 MoM),

Elevated hCG (> 3.0 MoM) and

Inhibin A (≥ 2.0 MoM),

low unconjugated estriol (< 0.5 MoM) and the

combined triple test

3 minor risk factors:

Ut A D at 20-24 W:

Abnormal [PI]

>95th centile:

Serial US for fetal size

and Um A D at 26-28 w

Ut AD: Normal Ut AD:

Notch

Decreased diastolic flow

2. At each ANV from 24 W:

Serial SFH: <10th centile or static:

US of fetal size & UmAD at 28 w.

II. Diagnosis

AC or EFW < 10th centile

Reduced growth velocity:

AC or EFW at least 3 w apart

{minimize false–positive rates for diagnosing FGR}.

: serial assessment of fetal size and UA Doppler.

Transverse abdominal Triad

Deep portion of portal vein

(J sign)

Spine

Stomach

III. Investigations Severe SGA:

1. Detailed fetal anatomical survey and uterine

artery Doppler

2. Serological screening for CMV and toxoplasmosis

3. With structural anomalies: Karyotyping

High risk population:

Testing for syphilis and malaria .

IV. Surveillance 1. Umbilical artery Doppler

Every 14 days.

More frequent: severe SGA

Twice weekly: abnormal U A D

(PI or RI > +2 SDs above mean for ges age) and

end–diastolic velocities present

Daily: absent/reversed end–diastolic

Normal

Absent

Reversed

2. MCA Doppler

In preterm SGA:

limited accuracy: should not be used

In term SGA:

Normal UA Doppler, an abnormal MCA Doppler

(PI < 5th centile) has moderate predictive value for

acidosis at birth: used to time delivery.

IUGR Normal

A: The normal middle cerebral artery

flow pattern has relatively

little diastolic flow

B: With elevation of placental blood

flow resistance the changes in the

middle cerebral artery waveform may

be subtle, although the

cerebroplacental ratio may become

abnormal.

C: With progressive placental

dysfunction there may be an increase

in the diastolic velocity, resulting in a

decrease in the Doppler index (Brain

sparing

D: With marked brain sparing, the

systolic down slope of the waveform

becomes smoother so that the

waveform almost resembles that of

the umbilical artery. The associated

rise in the mean velocity results in a

marked decline in the

Doppler index.

3. Ductus venosus (DV) and umbilical vein (UV)

Doppler

Moderate predictive value: used in the preterm

SGA with abnormal UA Doppler and to time

delivery.

In the ductus venosus blood flow is always antegrade throughout the cardiac

cycle under normal circumstances.

Pulsatility is less pronounced in waveform patterns obtained at the inlet (A)

versus the outlet (B). With impaired cardiac forward function there is a decline

in forward flow during atrial systole (C). If progressive atrial forward flow may be

lost (D) or reversed (E, F).

4. CTG or

Amniotic fluid volume

not be used as the only form

Biophysical profile should not be used

V. Delivery Corticosteroids

Single course

Between

Vaginal delivery: 24+0 and 35+6 w

CS: 24+0 and 38+6 w.

Timing: Normal Um AD

-At 37 w

-At 34 W:

Static growth over 4 w

MCA PI < 5 centile

EDV present but PI or RI >2SD

-At 37 w

-At 34 W:

Static growth over 3 w

AREDV

-At 32 w

-Before 32w:

Abnormal DV Doppler

Mode

AREDV:

CS

Normal UA Doppler or

Abnormal UA PI but end–diastolic velocities

present:

IOL +

continuous FHR monitoring

CS

At booking: 1 major risk factor

or 3 minor risk factor

At each ANV: SFH <10 centile or

static

Reassess at 20 w

Abnormal D synd marker (minor)

F echogenic bowel (major)

Ut a Doppler at 20-24 w

3 minor R factors 1 major R factor

Normal Abnormal

Reassess F size and Um

A Doppler in 3rd T

Serial assessment of F size and um A

Doppler 26-28w

Thank you