Pregnant women go through a barrage of tests early on in a pregnancy. Tests are run for blood type, gestational diabetes, anemia, STDs, cervical cancer, and immunity to a whole host of diseases.
Fetuses also go through a number of tests, some optional, some not, as a pregnancy progresses. These include tests for chromosomal disorders, birth defects like Spina bifida and Anencephaly, and Down's Syndrome, amongst many others, including the more innocuous ultrasound or amniocentisis to find out the baby's sex.
As our medical technology and expertise has advanced with time, so have the tests. New tests are added to the list as new problems arise (for instance, thirty years ago there was no AIDS test for expectant mothers, but now there is) and new options in birthing and anesthesia are continually coming in and out of vogue.
Reminds me of a great bumper sticker I saw recently:
"If the fetus you save is gay, will you still fight for its rights?"
What if a devout Christian conservative who is very serious about battling the "homosexual agenda" could test for the gay gene while pregnant? What do you do when you know you are going to give birth to a child you will never really be able to love? Or would your entire philosophy on sexual orientation change? Or would your entire philosophy on abortion change? Or would you give your baby up for adoption, unable to bear the site of your very own gay child?
Would you be able to "hate the sin, not the sinner?"
Welcome to the big gray area of the future. It might never happen, but once upon a time, our ancestors believed that the world was flat, that the sun revolved around the earth, that if a person thrown in a lake sank instead of floating that person was clearly not guilty of practicing witchcraft... Not so long ago, no one thought twice about lighting up when pregnant, drinking and driving, unconventional weapons on airplanes, etc...
The world changes very quickly these days. Food for thought.