00:01
Now, we will discuss
Antenatal Testing.
00:06
So the purpose of antenatal testing
is to ensure fetal well-being.
00:10
And when we say, reassure us
or ensure fetal well-being,
we mean that there are no signs
of fetal asphyxia.
00:18
So let's first talk about
the non-stress test.
00:22
So the non-stress test
is performed
by doing the
external fetal monitoring
to look at the fetal heart rate.
00:29
We then determine if
the fetal heart rate is reactive,
which means fetal well-being
is reassured,
or is it non-reactive,
meaning there's additional
testing needed to be done
to assure fetal well-being.
00:42
Reactive.
And this is very important
means that there
is two accelerations
of greater than
15 beats per minute,
lasting at least 15 seconds
over a 20 minute time period.
00:53
So again, you're looking at a
20 minute time period
on the external fetal monitor,
and you're looking to find
two accelerations
of greater than
15 beats per minute,
each lasting for at least
15 seconds.
01:06
So the next type of antenal testing
is the biophysical profile.
01:11
Now with the biophysical profile,
you're looking at
five different categories
expecting to see certain things
in this category.
01:19
Patients are given a two
if the fetus performs the maneuvers
that we're looking for,
and a zero if they do not
perform the maneuvers.
01:28
Again, you have 30 minutes
to observe it.
01:30
So we're looking at fetal movement.
01:33
We're looking at fetal tone,
fetal breathing,
the amniotic fluid,
and again,
the non-stress test.
01:40
So with the fetal movement,
we're looking to see
three gross movements
within that 30 minute time period.
01:47
Fetal tone is looking for
fine movements,
like the hands moving the fingers
opening and closing the palm.
01:53
Fetal breathing,
we're looking for
sustained breathing
for 30 seconds
over that 30 minute time period.
01:59
Amniotic fluid volume,
really, we're just looking at the
maximum vertical pocket
and we want that to be
at least two centimeters.
02:06
And then we've already discussed
the non-stress test.
02:10
So if we have a score of eight,
that is reassuring.
02:12
That means that
that fetus is doing well
and there's no signs of
fetal asphyxia.
02:17
If there's a score of six,
this is considered equivocal.
02:21
So it doesn't mean
that we are reassured
but it also doesn't mean that
the baby is concerning for asphyxia.
02:27
However, if the patient is term,
meaning 37-weeks,
that means we need to deliver
that fetus.
02:34
At a score of four,
it is a little bit concerned this
for asphyxia
and we do need to deliver
at that point.
02:41
So the biophysical profile
can be used
when the non-stress test
is not reactive
as a confirmation
that the baby is doing okay.
02:51
So the next antenatal testing that
we use is a contraction stress test.
02:56
So with the contraction stress test,
we induce contractions,
and that can either be
through nipple stimulation,
or it can be induced
by given pitocin.
03:05
And we're looking to see
that a patient has contractions
over a 10-minute timeframe.
03:11
Now, this test,
we do not want to be positive.
03:14
So it's a little different
than the non-stress test.
03:17
If the test is positive,
that means
that more than
50% of the contractions
are associated
with a late deceleration.
03:25
The test is equivocal when
there's intimate late decelerations
but less than 50%.
03:31
And the test is negative
when there's less than
50% of the contractions
associated with late decelerations.
03:37
Again, for the
contraction stress test,
we want a negative result
to reassure us that the fetus
can tolerate labor.
03:45
Pay attention to this slide
because this is high yield.
03:50
And then the final test
is the Umbilical artery doppler.
03:53
Now this is a test is performed
by doing an ultrasound
looking at the doppler
of the umbilical artery.
04:00
And we do this when we are suspected
in fetal growth restriction.
04:04
Now our results can show
a normal S/D
Systolic/diastolic ratio
or it can show absent
or even worse
it can show reversal flow.
04:14
If it is, if there were flow
is absent or reversal
then that indicates that there is
an increased resistance
in the placenta.
04:23
So let's look at a question.
04:25
A 27-year-old
gravida 1 para 0 female
at 28 weeks and
3 days of gestation
with a history of
chronic hypertension
presents for an antenatal visit.
04:35
She has had no issues
this pregnancy.
04:38
All antenatal testing has been
within normal limits.
04:41
She takes labetalol for her
chronic hypertension.
04:44
On physical exam,
her blood pressure is 140/95.
04:47
The fetal heart rate is
150 beats per minute,
And the fundal height for the mom
is 23 centimeters.
04:56
Now when we think about that,
23 centimeters
at 28 weeks gestation
that sounds a little small
to me.
05:04
So the next best step
in her management is...
05:07
A. A fetal ultrasound.
05:09
B. Fetal doppler
of the umbilical artery.
05:11
C. Contractions stress test.
05:13
or D. Biophysical profile.
05:17
So in this case,
we first want to do
a fetal ultrasound.
05:20
Now, there's lots of reasons why
the fundal height may be small.
05:23
It could be because there's
decreased amniotic fluid.
05:26
It could be because
the baby is small,
or it could be our measurements
are not that great.
05:30
So we want to confirm that
the measurement is small
first by fetal ultrasound.
05:34
If the fetus is indeed small,
then the fetus will warrant
a fetal Doppler
of the umbilical artery.
05:40
But the next best step
in her management
is to perform the fetal ultrasound.