LifeLink: Genetic Testing

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December 2005

Genetic testing, whereby tests are performed in utero to determine the health of the child, is now included as standard in prenatal care. Unborn children are screened in the womb for Down’s Syndrome, cystic fibrosis, susceptibility to some types of breast cancer, fragile X syndrome, Huntington’s disease, Duchenne muscular dystrophy, and various types of degeneration of the brainstem, spinal cord and peripheral nerves. However, these discoveries raise the question of what happens after a family finds that their child does have one of these debilitating diseases. Are we seeking this information so that we can treat our unborn children more effectively (with, for example, prenatal surgery to correct spina bifida), or do we intend to abort our children before they even have a chance to grow? Often, the physicians and prenatal care team pressure the parents to abort when a severe health problem is discovered in utero.

Common Prenatal Tests

Chorionic Villus Sampling (CVS)
Suggested between 10 and 13 weeks of gestation, this test is an alternative to amniocentesis because it can be performed earlier in the pregnancy. Chorionic villi are tiny finger-like units that make up the placenta; they have the same chromosomes and genetic makeup as the baby. This test removes some of the chorionic villi and tests them for chromosomal abnormalities. One of every 100 procedures results in a miscarriage.

Amniocentesis
Suggested between 15 and 20 weeks of gestation, this procedure uses a needle to penetrate the amniotic sac, drawing amniotic fluid for testing. Amniocentesis serves to detect Down’s syndrome, spina bifida, anencephaly, and inherited metabolic disorders. One of every 200-400 procedures results in a miscarriage. The baby is also at risk for being harmed by the needle as it enters the amniotic sac.

Maternal Blood Screening/Multiple Marker Screening
Suggested between weeks 15 and 20, this screening measures levels of alpha-fetoprotein (AFP), estriol, human chorionic gonadotropin (HCG), and sometimes inhibin A in the mother’s blood. These markers help determine risk for Down’s syndrome. This screening test determines risk only and does not diagnose a condition.

Ultrasound
Ultrasounds were once used only in high-risk pregnancies but have become part of routine prenatal care. The standard ultrasound is generally performed between weeks 16 and 20, while a targeted ultrasound (meant to follow up on a specific concern) will often be performed later. In this test, sound waves are bounced off the baby’s bones and tissue to create an image of the baby. Skeletal or structural defects such as spina bifida and anencephaly, Down’s syndrome, congenital heart defects, gastrointestinal and kidney malformations, and cleft lip or palate can be recognized through ultrasound.

Some New Genetic Testing

A recent study conducted on 38,000 American women reveals that Down’s Syndrome can now be detected at just 11 weeks after conception. This new test is slightly more accurate than the current quadruple test offered at 16 weeks gestation. It does, still, have about a 5% false positive rate.

Unfortunately, many families who find that they have a child who is “imperfect” choose to end that baby’s life through abortion. Eighty to ninety percent of parents who find that their child has Down’s Syndrome choose to abort that child. The parent’s subjective view of their child’s quality of life, often coupled with pressure from the medical community, becomes the determining factor for whether or not that child is allowed to live.

Other genetic tests can now even screen unborn babies for low intelligence. This test can identify a range of genetic defects that generally lead to learning difficulties. Currently, this test is used only outside of the womb, screening the DNA of embryonic children before implantation during in vitro fertilization. The "less than perfect" embryonic children are simply discarded.

Some experts are concerned that such testing echoes Aldous Huxley's Brave New World, in which epsilon babies were bred in hatcheries for menial tasks, while alphas lived a life of luxury. "There is an urgent need for regulation of what constitutes legitimate use of this type of genetic diagnosis," said Richard Nicholson, the editor of the Bulletin of Medical Ethics. "This is a significant step towards eugenics."