Njm10/28/04

**Q** When should antenatal testing start after a previous IUFD? at 34
weeks? Or prior to the gestational age of the previous IUFD?

**A** Probably neither, unless you know the exact etiology of the prior
IUFD, but there is more. See below

Starting NSTs at the same gestational age, or slightly before the
gestational age of the previous IUFD, may be helpful if it was a known
recurring etiology. Unfortunately the cause of the previous IUFD is not
always clear in many cases.

Another common approach is to routinely start antenatal testing after a
previous IUFD at 34 weeks. That approach may be more practical,
especially if the IUFD was in the late second trimester, but better
management would be based on the exact etiology of the previous demise.
If one works from the exact previous etiology, then you could make a
more specific recommendation.

As you can see the vast majority are either not recurring etiologies, or
simply unexplained

<http://www.uptodateonline.com/application/image.asp?file=obst_pix/freque5.gif>

Fetal cause

<http://www.uptodateonline.com/application/image.asp?file=obst_pix/fetal_ca.gif>

Maternal cause

<http://www.uptodateonline.com/application/image.asp?file=obst_pix/matern2.gif>

Placental cause

<http://www.uptodateonline.com/application/image.asp?file=obst_pix/placen2.gif>

Gabbe (4th Ed.) recommends an approach which includes kick counts at 28
weeks, avoiding illicit drugs, and performing antenatal testing for
indications inter-current to the present pregnancy.

For example, if recurrent anti-phospholipid syndrome, then do NSTs
should be based on that diagnosis; if the patient had an IUFD because of
a non-recurrent congenital anomaly that has not recurred, then don't do
any NSTs at all unless otherwise indicated

**\*PROGNOSIS** --- The risk of recurrent fetal demise is not known, but
clearly depends upon the cause of the index death. For example, the risk
of Trisomy 21 (47,+21) in a subsequent fetus is approximately one
percent, whereas recurrent nonimmune hydrops from alpha-thalassemia is
likely in 25 percent of offspring.

There were no recurrences in one series of 92 deliveries after
stillbirth
\[[104](http://www.uptodateonline.com/application/abstract.asp?TR=pregcomp/8214&viewAbs=104&title=104)\].
By comparison, another study found an 8 percent rate of repeat
stillbirth, particularly among women with hypertension and diabetes
\[[105](http://www.uptodateonline.com/application/abstract.asp?TR=pregcomp/8214&viewAbs=105&title=105)\].
A third report in which 300 women with a previous history of stillbirth
were followed with antepartum fetal surveillance noted one unexplained
fetal death in a woman with two previous, unexplained fetal deaths
\[[106](http://www.uptodateonline.com/application/abstract.asp?TR=pregcomp/8214&viewAbs=106&title=106)\].
In most cases of fetal death in which the etiology is known, a
recurrence risk can be determined and sometimes prenatal diagnosis and
prevention are possible. Women with an unexplained fetal death can be
reassured that the risk of recurrence is low. An exception may be second
trimester fetal death, which appears to be associated with a higher risk
of recurrence than third trimester fetal loss
\[[107,108](http://www.uptodateonline.com/application/abstract.asp?TR=pregcomp/8214&viewAbs=107~108&title=107,108)\].

When uteroplacental insufficiency is the cause of the fetal demise,
there is a risk of recurrence, which may be manifested by other sequelae
of this process. For example, stillbirth in a previous pregnancy is also
associated with having a preterm birth or small for gestational age
infant in the subsequent pregnancy
\[[109,110](http://www.uptodateonline.com/application/abstract.asp?TR=pregcomp/8214&viewAbs=109~110&title=109,110)\].

<http://www.uptodateonline.com/application/topic.asp?file=pregcomp/8214&type=A&selectedTitle=1~53>

In summary, the best management for antenatal testing after an IUFD
would be based on the exact etiology of the previous demise. If one
makes a management plan based on the exact previous etiology, then you
could make a more specific recommendation. If the records do not clearly
state the cause of the previous IUFD, then one common approach is to
begin weekly NSTs at 34 weeks gestation.