It is a procedure in which a
small amount of the amniotic fluid (about 20 cc) surrounding the fetus is
withdrawn for testing for chromosomes and genetic
This is done by inserting a very fine
needle through the mother’s abdomen into the uterus under ultrasound guidance.
The procedure is performed on an
outpatient basis and takes only a few minutes.
Most women do not experience any
pain and a local anesthetic is not necessary. The needle may cause some pain when
it penetrates the uterus, but the pain should not last long and should not hurt
more than an injection into any other part of the body.
After the fluid has been
withdrawn, the removal of the needle will cause no further discomfort. The fluid is then sent to the laboratory for analysis.
The majority of amniocentesis
are done for the detection of chromosomal disorders.
Chromosomes carry genes that
pass certain characteristics from parents to
their children. When there are too many or too few chromosomes or there is a
defect in a chromosome, birth defects can occur.
Down Syndrome is the most common
chromosomal disorder. It causes mental retardation and other health problems
such as heart defects. Other less common chromosomal disorders may lead
to serious handicaps and death.
Amniocentesis is usually performed between 16th to 20th
weeks of pregnancy.
Usually it takes about 2–3 weeks. If you wish, a
rapid test can provide a preliminary report in 3 working days (additional charge applies).
No. Amniocentesis can detect almost all known chromosomal disorders. However, birth defects not due
to chromosomal abnormalities cannot be detected through this test.
There may be other reasons that
apply uniquely to you. Both you and your
obstetrician should decide together if you need an Amniocentesis.
Amniocentesis is a safe, low risk procedure when done
by experienced medical experts. The risk of miscarriage following the test is
reported to be 0.3-0.5%