Prenatal screening and the assessment of risk: the view from the other side.

Since the introduction, in 1984, of maternal serum screening for fetal aneuploidy, obstetrical practitioners and their patients have learned to cope with the challenges and limitations of risk estimation. In the instance where the "odds" are not entirely reassuring, the hazards of invasive, yet definitive, testing are weighed against the costs of uncertainty. Non-invasive prenatal screening has improved dramatically over the past 20 years, with early administration, high sensitivity, and low false positive rates as the benchmarks. With a wide array of tests at her disposal, the woman who chooses to undergo prenatal screening for aneuploidy presumably does so in the context of counselling and consent, and with the assurance that the tests offered, having evolved through the rigours of large-scale clinical trials, are as good as they can possibly be. Or does she? The following is a highly personal account of one woman's experience with prenatal screening, in particular, with the "Pandora's box" of ultrasonic soft markers for aneuploidy. The author challenges the experts in the field to ensure that all "advancements" meet the standards described above.