Preferences of women facing a prenatal diagnostic choice: long-term outcomes matter most.

Women aged 35 or older who wish to undergo prenatal diagnosis for chromosomal disorders are typically offered a choice between chorionic villus sampling or amniocentesis. These two tests are performed at different times and impose differing miscarriage risks. In deciding which test to use, therefore, women need to consider both short-term consequences (e.g. timing of pregnancy loss, should it occur) and long-term consequences (e.g. whether a pregnancy loss is followed by a future birth). We examined how women seeking prenatal diagnostic services value the outcomes of testing. We conducted a cross-sectional study of 72 women seeking genetic counselling at the University of California at San Francisco or Kaiser San Francisco. We measured preferences for outcomes (utilities) of prenatal diagnosis using the standard gamble metric. We also assessed demographics and attitudes via questionnaire. We observed no differences in mean utilities assigned to first- versus second-trimester pregnancy losses with similar long-term sequelae. Utilities for losses followed by future birth, however, were significantly higher than utilities for losses without future birth (range 0.91 to 0.93 versus 0.84 to 0.86, p<0.05 for all comparisons). In addition, we observed substantial variation in utilities across women. Long-term outcomes matter most to these women. In presenting prenatal diagnostic options to their patients, clinicians should include discussion of outcomes such as the likelihood of future birth in the event of a pregnancy loss. Furthermore, the substantial variation in utilities we observed suggests that future prenatal testing policies should account for the preferences of the individual woman.