1st Trimester Detection Of Trisomy 21
First, some history:
The formal story began in 1866, when a physician named John Langdon Down published an essay in England in which he described a set of children with common features who were distinct from other children with mental retardation. Down was superintendent of an asylum for children with mental retardation in Surrey, England when he made the first distinction between children who were cretins (later to be found to have hypothyroidism) and what he referred to as “Mongoloids.”
Down based this unfortunate name on his notion that these children looked like people from Mongolia, who were thought then to have an arrested development. This ethnic insult came under fire in the early 1960s from Asian genetic researchers, and the term was dropped from scientific use. Instead, the condition became called “Down’s syndrome.” In the 1970s, an American revision of scientific terms changed it simply to “Down syndrome,” while it still is called “Down’s” in the UK and some places in Europe.
In the first part of the twentieth century, there was much speculation of the cause of Down syndrome. The first people to speculate that it might be due to chromosomal abnormalities were Waardenburg and Bleyer in the 1930s. But it wasn’t until 1959 that Jerome Lejeune and Patricia Jacobs, working independently, first determined the cause to be trisomy (triplication) of the 21st chromosome. Cases of Down syndrome due to translocation and mosaicism […] were described over the next three years.
Now the Wash Post is reporting that new tests allow women an opportunity to find out in their first trimester if their child may potentially have “Trisomy 21 (Down syndrome.”
A first-trimester screening test can reliably identify fetuses likely to be born with Down syndrome, providing expectant women with that information much earlier in a pregnancy than current testing allows, according to a major study being released today.
The eagerly awaited study of more than 38,000 U.S. women — the largest ever conducted — found that the screening method, which combines a blood test with an ultrasound exam, can pinpoint many fetuses with the common genetic disorder 11 weeks after conception. That allows women to decide sooner whether to undergo the riskier follow-up testing needed to confirm the diagnosis.
“This is a big deal for women. It’s going to have a big impact on care for women, not just in the United States but throughout the world,” said Fergal D. Malone of the Royal College of Surgeons in Dublin, who led the study published in today’s issue of the New England Journal of Medicine.
And, of course, this has implications for abortion decisions:
Screening women before the second trimester allows those who might opt to terminate a pregnancy to make that decision when doctors say an abortion is safer and less traumatic. It also gives those who want to continue the pregnancy more time to prepare emotionally for their child’s condition, and provides earlier reassurance to those whose babies are healthy, avoiding weeks of anxiety, Malone and others said.
These are tough decisions, and technology isn’t making them any easier. It’s just making the time between conception and decision shorter.
What do you think?