Prenatal Chromosome Analysis
Laboratory
Studies Request Form |
CPT Codes/Price
List (PDF)
Prenatal chromosome analysis is indicated in the following cases:
- Couples at increased
risk of having infants with abnormal chromosomes
- Advanced maternal
age - 35 years or older
- Previous child with
a chromosome disorder such as Down syndrome
- One member of the
couple is known to carry a chromosome rearrangement
- In certain cases,
relatives of a child with a chromosome disorder
- Multiple (two or
more) spontaneous abortions
- Couples at risk
for having children with X-linked disorders for which molecular
testing may not be available.
- Pregnancies at increased
risk of chromosome defects due to finding of fetal defects on
ultrasound.
- Pregnancies identified
by prenatal serum screening to be at increased risk for neural
tube defects or chromosome defects.
Amniotic Fluid
for Prenatal Chromosome Analysis
Specimen
requirements:
20 to 30 ml amniotic fluid collected in 2 to 3 sterile tubes.
The first few mls of fluid should be discarded as they increase
the likelihood of maternal cell contamination. The following
information should accompany the specimen: patient's name, physician's
name, date collected, EGA by ultrasound, LMP (if available),
maternal age, and indication for study. Sterile tubes and
mailers are available from the Greenwood Genetic Center.
Transport: Specimen should be kept at room temperature;
do not freeze or refrigerate. Specimen should be sent
by courier or overnight mail to arrive at the laboratory within
24 hours.
Analysis: A minimum of 15 cells representing at least
10 distinct colonies are counted and 5 cells are analyzed from
G-banded preparations. Hard copies of two karyotypes and 3 chromosome
spreads are retained for documentation.
Report: Results are called to the referring physician
in 7 to 10 days. The final report is mailed to the physician's
office. Patient consultation is available.
CPT Codes: 88235, 88269, 88280, 88285,
88291
Chorionic Villus Sampling [CVS] for Prenatal Chromosome
Analysis
Chorionic villus sampling is a method for first trimester prenatal
diagnosis of chromosome disorders. Chromosome analysis is performed
on a villus biopsy by harvest following a short-term culture.
CVS is performed earlier in pregnancy than amniocentesis. However,
in about 3% of cases, an ambiguous result may be obtained from
CVS, which necessitates follow-up amniocentesis for confirmation
or clarification. While CVS has the advantage of providing an
earlier result to the mother, the CVS procedure does not permit
analysis of alpha-fetoprotein. Therefore, if the indication
for study is increased risk of a neural tube defect, the amniocentesis
rather than CVS would be recommended.
Specimen requirements: 5-10 mg
of chorionic villi obtained in 10 ml of transport media. The
following information should accompany the specimen: patient's
name, physician's name, date collected, EGA by ultrasound, LMP
(if available), maternal age, and indication for study.
Sterile
tubes, transport media, and mailers are available from the Greenwood
Genetic Center.
Transport: Specimen should be kept at
room temperature; do not freeze or refrigerate. Specimen
should be sent by courier or overnight mail to arrive at the
laboratory within 24 hours.
Analysis: At least 15 cells representing
at least 10 distinct colonies are counted and 5 cells are completely
analyzed from G-banded preparations. Hard copies of two karyotypes
and 3 chromosome spreads are retained for documentation.
Report: Results are called to the
referring physician in 7 to 10 days. The final report is faxed
and mailed to the physician's office. Patient consultation
is available.
CPT Codes: 88235, 88267, 88280, 88285,
88291 |
