Questioning a statistics.

I saw a random fact quote in a magazine yesterday. (Is that opening as lazy as beginning with "I was sharing a taxi"?) I didn't double check it anywhere, but I have been thinking about it. It said "90% of pregnancies that test positive for Down Syndrome are aborted".

Really?! 90%? That seems really high, particularly for such a common birth defect. It's a deformity where the fetus is still viable, the families who include a down syndrome child report being happy, and while the defect results in lower IQ and cardiovascular problems, many affected persons do live out full productive lives.

The statistic as printed indicates that 90% of people who find out they're having a child with DS will choose to end it, with an implication that more women should be tested so that they have an opportunity to "opt out" so to speak. I don't think that's the whole story.

First, the tests are usually offered to older mothers (over 35 yrs). They're also more likely to be more affluent--women who delayed their families to develop their careers for example, or families that can afford to have the tests. They're usually extras--so insurance often won't cover the cost.

The tests also result in a high rate of false positives. So having one test will lead to an extra level of anxiety while the parents wait for the test confirmation.

Perhaps its only people who will choose to terminate that have the tests. After all, why go through the extra expense and anxiety if your choice is already made and your actions won't change?

The follow on question is: Where along the spectrum of pregnancy outcomes do people draw the line to terminate? Which lives are more valuable? Down Syndrome is something that can be justified either way. Clearly there are other defects where most people would agree to end the pregnancy--I hope that's somewhere on the non-viable end of the spectrum. There are places where the ethics become very cloudy--China for example, where reportedly the decision is made based on gender. Most of us in the US think that's abhorrent.

There are other traits that are might be cloudy even here--autism, mental illness, diabetes. There are traits that are desirable, and a few people might be willing to select for--athleticism, charisma, IQ, height. (No, I'm not joking--apparently there are a number of Little People who are selecting for dwarfism and a number of deaf people selecting for deafness so that their children will share the same types of life experiences.)

Where do you draw the line? Do we as a society want to allow people to select against birth defects? Conversely, should we allow families to select in favor of birth defects where the parents are already affected? Should we even try to set limits, or is it best to leave those decisions--all of those decisions--with the future parents?