If you could know whether your unborn child was going to be born with a genetic defect, would you want that information?Thatisthe basis of a quad test, offered to every pregnant woman, the first in a series of detection tools to determine if something is off with the fetus.
In part one of this three part series on genetic selection, 7News looks into how this test works and the conflict between nature and science.
When Melanie and Rick Sarro of Lake Charlesdecided to start a family later in life, they knew it carried a risk for pregnancy problems, but that did notdeter their plans. "We knew that we wanted to have children and that we were gonna have to not waste any time to do it," said Melanie.
Before the Sarros celebrated their third anniversary, Zachary was here and baby number two was on the way."The pregnancywent very smoothly, it was uneventful," said Rick, "so it was a joyous event for both of them."
Because of Melanie's age, 37, her doctor offered a standard quad test, something she did.
Dr. Marshall St. Amant is the Director of Maternal Fetal Medicine at Woman's Hospital in Baton Rouge and his team of physicians travels to Lake Charles a few times a week to treat local women with high risk pregnancies. He says asimple blood test canshow a woman's risk for genetic defects. "Itnever tells you for sure that the baby has a problem or does not have the problem you're looking for," he said, "it just says the risk is greater than or less than her predetermined risk by her age."
If the quad test does show that the mother is at risk of having a child with a genetic abnormality, then an amniocentesis is offered under the guidance of ultrasound technology with athin needle. "The fluid is removed over a period of a couple of minutes and then it's sent to a laboratory for a very specialized analysis,"said Dr. St. Amant.
Amniocentesis is the gold standard for diagnosing genetic disorders, analyzing every chromosome."It will identify any numerical abnormality of the chromosomes, being a whole extra copy of a chromosome. It will also identify broken chromosomes," said Dr.St. Amant.
Defects are reported on a caryotype with nearly 100 percent accuracy.
The most common findings are on chromosome 18, known as Edwards syndrome and on 21, Down syndrome."The patient would be offered the ability to continue the pregnancy," said Dr. St.Amant, "a secondary alternative would be the patient would be offered the ability to end the pregnancy."
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Genetic testing of a fetus offered for pregnant women