"What will be, will be"

Choosing not to undergo prenatal testing can be equally agonizing. "We felt that it would be more stressful for us to worry about something that may or may not happen at the end of nine months, so we didn't want to have the tests," explains Amy Gerborg of Alpharetta, Georgia. "I had a high-risk pregnancy that required me to have an ultrasound every month for the first trimester, then every other week, and then every week, so I already had enough to worry about without adding the stress of those tests."

Amanda Stiebel of St. Louis, Missouri, also had plenty to worry about. "At our 20-week ultrasound, they told us that our son had an enlarged brain ventricle, and that it might mean retardation of some sort. They wanted us to have an amniocentesis to rule out Down syndrome," recalls Stiebel, then a first-time mom-to-be. "After we finished crying, my husband and I decided that even if he were mentally disabled, we would love him and give him as good a life as possible, so the risks of an amnio weren't necessary. We did opt to have monthly ultrasounds and an MRI, however. By the eighth month, they announced that he had grown out of (or into) his ventricle and would be fine. Now, he's a perfect 1-year-old and we're glad we didn't risk losing him over a minor abnormality that turned out to be nothing."

For some women, screening tests are a concern because they may have a "false positive" or other uncertain result, says Jacky Halliday, a genetic counselor with the Prenatal Diagnosis Center at Women and Infants' Hospital in Providence, Rhode Island. Dee Rockman of Flint, Michigan, experienced a false positive herself. During her first pregnancy, all the test results came back fine. But with her second child, the maternal serum screen indicated her baby might have a serious chromosome disorder, Trisomy 18, which is often fatal. "I didn't think a thing of having the test, so it was a real shock when the nurse said, 'I'm sorry, we're going to have to get you in to see a neonatologist,'" Rockman remembers. The doctor performed an ultrasound that showed that the fetus did not have the physical symptoms of the disorder, "but he said if I wanted to be 100 percent sure I needed to have an amniocentesis." Rockman went ahead with the amnio and, fortunately, her daughter was fine. Though the end result was a relief, the experience was traumatic for Rockman.

Most people are used to "yes" and "no" answers, explains Halliday, but screening tests like the one Rockman had only indicate the possibility of a condition, leaving some moms-to-be with the difficult decision of whether or not to confirm that possibility with further (and maybe riskier) tests.