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From: liz@umcp-cs.UUCP
Newsgroups: net.women
Subject: amniocentesis
Message-ID: <2260@umcp-cs.UUCP>
Date: Tue, 30-Aug-83 22:29:38 EDT
Article-I.D.: umcp-cs.2260
Posted: Tue Aug 30 22:29:38 1983
Date-Received: Thu, 1-Sep-83 04:06:44 EDT
Organization: Univ. of Maryland, Computer Science Dept.
Lines: 63

AMNIOCENTESIS:  FACT & FICTION  (reprinted without permission from
NFP News, No. 3, Spring 1983, Center for Life, Providence Health
Foundation, Washington, DC)

Amniocentesis, a procedure in which a small amount of amniotic
fluid is removed from around the baby for analysis, has become
routine for certain pregnant women considered "high risk."  Among
these are women over 35 and those having a child with either Down's
Syndrome or a neural tube defect.

Parents in these categories are often traumatized by statistics
emphasizing the likelihood of having a handicapped child.  For
example, a woman at age 35 will be told she has three times the
chance of giving birth to a child with Down's Syndrome compared to
younger women.  The actual statistical likelihood of that occurring
is one case out of 360.  In other words, her chance of having a
child without Down's is greater than 99.7%.  A mother who already
has a child with a neural tube defect has a 3% chance of having
another with that same disorder.  In 97% of the cases, however,
her baby will be unaffected.

According to Dr. Hymie Gordon, a geneticist with the Mayo Clinic,
most women receive a greatly exaggerated picture of the likelihood
of birth disorders while the risks of amniocentesis are downplayed.
He cites a study done by a committee appointed by the Medical
Research Council (MRC) of Great Britain which is the only
independently-directed, case-controlled study on the hazards of
amniocentesis.

The results belie the popular presentation of amniocentesis as
without risks.  In this study women undergoing the procedure
experienced a greater than 5% rate of serious complictions in the
pregnancy compared to a control group.  Hazards included spontaneous
abortion, threatened abortion, antepartum hemorrhage (necessitating
C section), rupture of membranes, stillbirth, neonatal death,
respiratory distress, and musculoskeletal anomolies such as severe
clubfoot and congenital dislocation of the hip.

Contrast this with the less than 1% risk (even at age 40) of Down's
Syndrome or the slightly more than 2% chance of discovering a neural
tube defect (closed tube defects will not be detected by amniocentesis).

In addition to the physical hazards involved, the usefulness of
amniocentesis is also limited by technical problems such as failure
to obtain sufficient sample, contamination of the fluid, inability
to grow a culture for chromosome analysis, or error in results.
In a significant number of cases (Gordon believes over 5% although
no adequate statistics exist) repetition of the procedure is required
introducing additional risk to the mother and her unborn child.

Gordon finds that couples who clearly understand the statistics
and the relative risks involved in amniocentesis invariably decline
the procedure.

It should be noted that the hazards discussed here refer to
amniocentesis prior to 20 weeks when pre-natal tests for abnormalities
are done.  Amniocentesis performed late in pregnancy to determine
the maturity of the baby is a much safer procedure.

-- 
				-Liz Allen, U of Maryland, College Park MD
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