Book of Medical Disorders in Pregnancy - Tintash

screen combining the maternal serum
assays may aid in increasing the
sensitivity and specificity of detection
for fetal abnormalities. The classic test is
the Òtriple screen for alpha fetoprotein
(MSAFP), beta-HCG, and estriol (uE3).
The "quadruple screen" adds inhibin A.
Condition MSAFP uE3 HCG
Neural
tube defect
Increased Normal Normal
Trisomy 21 Low Low Increased
Trisomy 18 Low Low Low
Molar
pregnancy
Multiple
gestation
Fetal death
(stillbirth)
Low Low
Gross examination:
Very
High
Increased Normal Increased
Increased Low Low
The most important procedure to
perform is simply to look at the fetus or
fetal parts. Obviously, examination of an
intact fetus is most useful, though
information can still be gained from
examination of fetal parts. The pattern of
gross abnormalities can often suggest a
possible chromosomal abnormality or a
syndrome. Abnormalities can often be
quite subtle, particularly the earlier the
gestational age. Consultations are obtained
with clinical geneticists to review
the findings. A description of the findings
is put into a report (surgical
pathology or autopsy). Examination of
the placenta is very important, because
the reason for the fetal loss may be a
placental problem.
Microscopic examination: Microscopic
findings are generally less useful than
198
gross examination for the fetus, but
microscopic examination of the placenta
is important. Microscopy can aid in
determination of gestational age (lung,
kidney maturity), presence of infection,
presence of neoplasia, or pre-sence of
"dysplasia" (abnormal organo-genesis).
Radiography: Standard anteriorposterior
and lateral radiographic views
are essential for analysis of the fetal
skeleton. Radiographs are useful for
comparison with prenatal ultrasound,
and help define anomalies when autopsy
consent is limited, or can help to
determine sites to be examined
microscopically.
Microbiologic culture: Culture can aid
in diagnosis or confirma-tion of
congenital infections. Examples of
congenital infection in-clude: T –
toxoplasmosis, O - other, such as Listeria
monocytogenes, group B stre-ptococcus,
syphilis, R – rubella C – cytomegalovirus,
H - herpes simplex or
human immunodeficiency virus (HIV)
cultures have to be appropriately obtained
with the proper media and sent
with the proper requisitions ("routine"
includes aerobic and anaerobic bacteria;
fungal and viral cultures must be
separately ordered). Viral cultures are
difficult and ex-pensive. Separate media
and collection procedures may be
necessary depending upon what virus is
being sought. Bac-terial contamination
can be a problem.
Karyotyping: Tissues must be obtained
as fresh as possible for culture and
without contamination. A useful
procedure is to wash the tissue samples
in sterile saline prior to placing them
into cell culture media. Tissues with the
best chance for growth are those with the