This is a screenshot
00:06
of the title page
00:07
of the aforementioned paper.
00:10
It was published in 2013,
00:12
a review article.
00:13

00:16
And this is what we’re going
00:18
to talk about today in today’s
00:20
presentation.
00:21
In section one,
00:21
we deal with definitions
00:24
between SGA and IUGR–
00:25
that
00:26
is small for gestational age
00:28
and intrauterine growth
00:29
restriction.
00:31
In section two,
00:31
we talk about the screening
00:33
methods for these two conditions
00:34
and possible ways in which they
00:36
can be improved.
00:37
In section three,
00:38
we talk about the management
00:39
and section four, we round off
00:41
with a summary of the points
00:43
which we find could have been
00:44
better in this article.
00:45

00:49
SGA is defined as a field birth
00:51
weight of less than 10%
00:53
of the total population.
00:54
And that is confirmed
00:55
by ultrasound.
00:57
Other sources have advocated
00:58
the use of 5% or 3%.
01:01
But basically it is an arbitrary
01:03
cutoff point at the moment,
01:04
whereas IUGR,
01:06
Intrauterine growth restriction,
01:07
is basically any condition
01:09
any in-utero condition,
01:11
which restricts the growth
01:12
of the fetus
01:13
to its full predicted age.
01:15
The causes can be broadly
01:16
classified as maternal,
01:18
placental, or fetal.
01:19
And on the slide,
01:20
you’ll see some examples.
01:22
Current definitions tend to use
01:24
these terms
01:25
quite interchangeably and more
01:27
accurate
01:27
use would say that IUGR is part
01:32
of SGA
01:33
and this is the basis
01:34
for the author’s paper
01:36
in which he goes about trying
01:38
to challenge
01:38
these current definitions.
01:39

01:43
The author goes on to say
01:44
that the term should be distinct
01:46
and should define them
01:47
differently as such
01:48
because this definition does not
01:49
make a distinction among infants
01:51
who are constitutionally small,
01:53
growth restricted small,
01:54
and not small birth, growth
01:56
restricted relative
01:57
to their potential.
01:58
As an example, as many as 70%
02:00
of fetuses who way
02:01
below the 10th percentile
02:02
for gestational age are small
02:04
simply
02:05
because the constitutional
02:06
factors such as female, sex,
02:07
or maternal ethnicity, perry,
02:10
or BMI.
02:11
They are not at high risk
02:12
of perinatal mortality
02:13
and morbidity
02:14
but
02:15
under the current definitions,
02:16
they would be defined as IUGR.
02:19
One further point is that if you
02:22
go by the 10% criteria for small
02:24
for gestational age,
02:26
if you take it for,
02:28
let’s say, this country and then
02:29
you go to another country,
02:31
you might find
02:32
that
02:32
under the same classification
02:33
you could end up with 23%– one
02:35
of the papers that we cited.
02:38
So obviously there needs to be
02:42
few changes in definition.
02:44
Now on the diagram,
02:45
you’ll see three
02:48
different examples of how
02:49
a fetus could be classified.
02:51
The first example is the fetus
02:53
is not small, but it is growth
02:54
restricted.
02:55
For example, it
02:56
is possible for a fetus
02:56
to be growth restricted,
02:57
but not be in the less than 10%
02:59
of estimated fetal weight.
03:02
On the other hand, a fetus could
03:04
be just constitutionally small
03:06
because of, let’s say,
03:07
parental factors
03:08
or other factors,
03:09
such as sex or ethnicity.
03:13
Finally, you could always have
03:14
a fetus that is both growth
03:16
restricted and small
03:17
and the author says that this
03:19
calls for a need for better
03:21
definitions.
03:21

03:25
Finally, the author goes on
03:26
to summarize his suggestions,
03:28
like how you see on the page
03:30
here.
03:31
The main thing is he still
03:33
decides to stick with just two
03:35
definitions
03:36
for this current problem
03:37
that we have.
03:40
So then he gives examples of how
03:42
these definitions can still
03:43
work.
03:43
For example CMV can still
03:45
be relatively easy classified
03:47
as IUGR still.
03:49
He admits that there will be
03:50
difficulty with some definition,
03:52
such as aneuploid fetus.
03:56
You might think that it might be
03:57
easily classified as SGA,
03:59
but the problem is aneuploid
04:01
fetuses are also correlated
04:03
with dis-functional placentas.
04:05
You could say that that is
04:06
because of the aneuploidia
04:07
itself and therefore you could
04:09
classify it as IUGR.
04:10
So the question is, do you
04:12
classify it as just SGA
04:14
by itself or do you classify it
04:16
in the middle right
04:17
there as SGA superimposed IUGR.
04:21
And this is one of the critiques
04:23
that we have of this paper,
04:24
is
04:24
that
04:24
under the current definitions
04:25
you do run into a lot
04:26
of problems.
04:27
And the main thing is things
04:29
which are even harder
04:31
to classify,
04:31
such as fetal alcohol syndrome.
04:33

04:36
It can’t easily be classified
04:38
under the current definitions
04:39
that we have.
04:40
And we’re surprised
04:41
because there are
04:42
other classification systems
04:45
currently in use.
04:46
And we’d like to propose one
04:48
which is probably better
04:49
than the current suggestions
04:53
by the author.
04:53

04:57
Rather than looking at just
04:59
the size of a fetus
05:00
or its possible causes,
05:01
we feel that there might be
05:04
better definitions in existence.
05:07
For example, one which looks
05:09
at also how likely the fetus
05:12
will benefit from ante natal
05:14
intervention
05:14
and whether or not
05:16
their outcomes are modifiable.
05:19
By doing this, we can avoid
05:21
subjecting fetuses
05:22
to unnecessary interventions.
05:26
So the diagram to your right,
05:27
you see that of all this year’s
05:28
fetuses,
05:29
40% are healthy small fetuses,
05:32
meaning that they are
05:32
constitutionally small,
05:34
as well as 20% of SGA fetuses
05:38
are intrinsically small, which
05:39
means either they have CMV
05:42
infections, fetal alcohol
05:44
syndrome, or a neuploidy.
05:47
By classifying it like this,
05:50
we are taking a more
05:51
clinical approach
05:52
and we’re saying
05:53
that these fetuses do not need
05:56
intervention.
05:58
And we feel that this is
05:59
a better approach to OB/GYN
06:02
practice.
06:05
And finally the 40%,
06:07
the darker 40% that you see
06:08
there,
06:09
which is growth restricted
06:12
SGA, now we’ve identified them
06:15
as possibly benefiting
06:17
from intervention and therefore
06:19
we are no longer concerned
06:21
whether or not FAS should be
06:23
classified as SGA or IUGR.
06:26
We are just sure that it is not
06:27
likely to benefit
06:28
from intervention
06:29
and we will not intervene.
06:31

06:34
Moving on, we will now talk
06:35
about current issues
06:38
in screening methods.
06:40
For example, we talk about how
06:42
to screen for fetal growth
06:44
abnormalities,
06:45
the current practices,
06:47
the accuracy of final height
06:48
measurements
06:49
and ultrasound and finally
06:50
the challenges in terms
06:51
of antenatal testing, doppler
06:53
ultrasound,
06:54
and timing of delivery.
06:55

06:57
For the remainder
06:58
of this presentation
07:00
SGA will be referred
07:01
to as those fetuses which we do
07:07
not feel
07:08
would benefit from intervention
07:09
while IUGR are those that will
07:11
be, for the sake of simplicity.
07:14
Now moving on, the author’s
07:15
suggestions to improve
07:18
the screening methods
07:19
are quite effective.
07:21
You see on your screen,
07:22
there are
07:22
several different factors which
07:24
play a part in an SGA or IUGR
07:26
fetus, things
07:27
such as maternal age, height,
07:29
weight, paternal height
07:32
and weight,
07:32
race, ethnicity, so on, so
07:34
forth.
07:35
These all play a part
07:36
in determining whether or not
07:38
a fetus is classified as SGA
07:40
or IUGR.
07:41
Now the author makes
07:43
a strong point in saying
07:44
that if we are able to account
07:46
for these factors,
07:48
then we are better
07:49
able to arrive at growth curves
07:51
which are more
07:51
predictive
07:53
of percentile estimates.
07:56
And by doing so,
07:57
we will be able to tell
08:00
whether or not intervention is
08:01
likely to benefit outcome.
08:03

08:06
We’d also like to add
08:07
that the recent literature is
08:08
in agreement with the author’s
08:10
viewpoints.
08:11
There have been several studies
08:13
trying to incorporate all
08:15
these different predictive
08:17
values into some sort
08:19
of algorithm.
08:21
The idea is one day we’ll
08:22
be able to enter all
08:23
the patients particulars
08:25
into a computer, and it will be
08:27
able to say whether or not
08:29
the fetus is indeed SGA or IUGR.
08:32

08:36
I will not discuss
08:37
about the management
08:38
of SGA/IUGR.
08:39
I
08:40
If SGA/IUGR is suspected,
08:42
the author suggested performing
08:44
antenatal testing, which
08:46
includes non-stress tests
08:48
and biophysical profile.
08:50
The biophysical profile in turn
08:51
includes fetal movement, tone,
08:54
breathing, AFI, and fetal heart
08:56
rate.
08:57
In addition, the author also
08:59
suggests performing
09:00
serial ultrasound growth scans
09:02
as a form
09:03
of fetal and anatomic survey,
09:06
as well as doppler blood flow
09:07
studies
09:08
to assess the amount of blood
09:09
flow to the fetus.
09:11
These suggestions are in line
09:13
with the current literature.
09:14
However when we did a literature
09:16
search, there are studies that
09:18
also support fetal karyotyping
09:20
to screen for karyotypes types
09:22
such as Trisome 21 and 18,
09:24
which may lead
09:25
to anatomical defect
09:26
in the fetus and has SGA/IUGR.
09:31
In addition, another study
09:32
suggested performing
09:33
maternal serum examination
09:35
for infection
09:36
such as corneal immunitis.
09:37

09:42
As part of antepartum
09:44
management, other literatures
09:45
have suggested repeating
09:46
ultrasounds one to two times
09:48
a week if normal,
09:49
but more frequently if result is
09:51
abnormal.
09:52
Another studies suggests
09:53
that glucocorticoids be given
09:55
to the mother for preterm
09:56
gestations
09:57
to aid in fetal maturity.
09:59
And of course, should the cause
10:01
of SGA be found, treatment
10:03
should be given to the mother
10:04
immediately.
10:05
For example, control
10:06
of hypertension in the mother,
10:09
and treatment of CMV
10:10
with antiviral hyperimmuno
10:12
globulin therapy.
10:14

10:17
There is, however,
10:18
an important question that
10:19
remained
10:20
elusive to obstetricians
10:21
even to today.
10:23
The key question is, how will
10:25
the neonate do
10:26
at a current gestation age
10:27
versus what is the ongoing risk
10:29
over the next week and outcome
10:31
if he achieves another week
10:32
of gestation.
10:33
There is however
10:34
little consensus
10:35
about the optimal time
10:36
of delivery of the fetus.
10:38
This is partly
10:39
due to the insufficient evidence
10:41
from randomized control trial.
10:42

10:45
If we guess to the delivery
10:47
timing of fetus
10:47
in the setting of SGA,
10:50
the author did however mention
10:51
some determinants that could
10:52
assist obstetricians into making
10:54
a delivery decision.
10:56
For example, the author
10:57
suggested doppler ultrasound
10:58
scanning, particularly looking
11:00
at the umbilical artery
11:01
as a determinant
11:02
for the decision
11:03
to deliver a fetus.
11:05
As you can see from the chart
11:06
here, should the ultrasound scan
11:09
show normal blood flow,
11:11
the author suggested
11:12
ongoing fetal assessment
11:14
one to two times per week
11:15
and expected management
11:17
to achieve fetal maturity.
11:19
However if there is
11:20
abnormal blood flow,
11:21
such as reverse end-diastolic
11:22
blood flow, the author suggested
11:25
delivery
11:25
at any viable gestation age.
11:28
If the abnormal blood flow is
11:30
in the form of increased
11:32
systolic or diastolic ratio
11:34
or absent diastolic blood flow
11:36
and the fetus is at least 24
11:38
to 25 weeks gestational age,
11:41
the author suggested
11:42
expectant measurement in view
11:43
of high risk and more
11:45
frequent evaluation
11:46
is indicated.
11:49
If the gestation age is more
11:50
than 25 weeks, the author
11:52
suggested weighing the risk
11:53
and benefits of delivering
11:55
the fetus.
11:56

11:59
The author also suggested
12:00
amniotic fluid index
12:02
as a determinant
12:03
for the delivery timing.
12:05
Although the AFI is
12:06
a crude measurement of mid
12:08
to long term placental function,
12:09
the author suggests earlier
12:10
delivery of fetus,
12:12
if oligohydramnios in a setting
12:14
of suspect IUGR.
12:16
In addition, there is also
12:17
a study that the auto quoted
12:18
that suggested
12:19
that every extra week
12:20
of intrauterine maturation
12:22
for the fetus
12:23
put twice the risk
12:24
of stillbirth.
12:25
Therefore, the recent benefit
12:27
of delaying delivery
12:28
may be complicated
12:29
with an increased risk
12:30
of stillbirth,
12:31
and this is an important factor
12:33
for all obstetricians
12:34
to take note.
12:34

12:37
This is a list
12:38
of relevant literatures
12:39
that we found on Pat Net.
12:41
Basically, there are
12:41
many different studies that
12:43
attempted to scrutinize
12:44
the different factors that may
12:45
improve the outcome of the fetus
12:47
in the setting of SGA.
12:49
For example, there was a study
12:51
that suggested
12:52
every single intrauterine day
12:54
improved the survival of fetus
12:55
by 1% to 2%
12:57
between the gestational age
12:58
of 26 to 29 weeks.
13:00
However, the issue is that there
13:02
is no breakthrough study that
13:04
has sufficient evidence to guide
13:05
the delivery of SGA fetus.
13:08
This is perhaps attributed
13:09
to the difficulty of performing
13:10
randomized controlled trial
13:11
in this area.
13:12

13:15
We did however manage to find
13:17
an author that tried to use
13:18
several parameters
13:19
such as abdominal,
13:20
circumference, growth rate,
13:22
biophysical profiling
13:24
to classify the severity
13:26
of IMGR.
13:27
In this study,
13:28
Harman and Baschat basically
13:30
used parameters as mentioned
13:31
earlier to stratify fetus
13:33
in IUGR setting into five
13:35
different gradings for which
13:36
each grading had a suggested
13:38
course of action to be taken.
13:40
For example, scenario one
13:42
is the least severe
13:43
and therefore expected
13:44
management is advice, where
13:46
as scenario five is the most
13:47
severe
13:48
and has delivery as soon
13:49
as possible is advised.
13:51
We feel that perhaps such a
13:53
graduated approach to IUGR
13:55
may be helpful to assist
13:57
obstetricians in judging
13:58
this issue.
13:58

14:01
Finally, I would like to provide
14:03
a summary of critique
14:04
for this article.
14:05
The author did point
14:06
out several important points.
14:08
For example, he recognized
14:09
the importance to differentiate
14:11
between SGA and IUGR,
14:12
and also proposed delineation
14:14
and better academic definitions
14:16
between SGA and IUGR.
14:18
In addition, he also attempted
14:20
to normalize measurements based
14:21
on multiple factors
14:22
such as parents height, weight,
14:24
ethnicity to remove confounding
14:26
variables in the diagnosis
14:27
of IUGR.
14:29
However, there are areas where
14:31
the author failed to discuss as
14:32
well.
14:33
For example, although he did
14:34
mention key management steps
14:35
of SGA, he omitted discussion
14:38
on categorization, profiles,
14:40
and graduated management steps
14:42
based on BPP and doppler
14:44
ultrasound,
14:45
as well as antepartum management
14:47
measures.
14:48
In addition, although he did
14:50
discuss the dilemma
14:50
between prematurity
14:51
and stillbirth,
14:53
he did not suggest
14:53
a clear framework on handling
14:55
the issue, thusly he did you not
14:57
mention
14:58
about the important randomized
14:59
trials that has been done so far
15:01
and the inconclusive results
15:02
from these trials.