PREFERENCES OF PREGNANT-WOMEN FOR AMNIOCENTESIS OR CHORIONIC VILLUS SAMPLING FOR PRENATAL TESTING - COMPARISON OF PATIENTS CHOICES AND THOSE OF A DECISION-ANALYTIC MODEL

Decision analytic models have suggested that the choice of amniocentes is or chorionic villus sampling for prenatal genetic testing is a util ity-driven decision. We compared preferences for prenatal testing amon g 156 pregnant women who had chosen either amniocentesis (n = 82) or c horionic villus sampling (n = 74) for the indication of maternal age. We also compared their choices with those of a decision-analytic model based on their preferences, and age-specific rates of spontaneous abo rtion and chromosomal abnormalities. Preferences were assessed using w ritten scenarios describing potential outcomes of prenatal testing, an d were recorded on linear rating scales. The differences in preference ratings for first- vs second-trimester prenatal diagnosis of a normal child (4.2 vs -1.6, p = 0.0004), and for first- vs second-trimester a bortion of an abnormal fetus (4.4 vs - 1.6, p = 0.01), were significan tly greater among women choosing chorionic villus sampling than among women choosing amniocentesis. There were no significant differences be tween chorionic villus sampling and amniocentesis patients in their pr eference ratings for test-related miscarriage, disconfirmed results at pregnancy termination, or maternal morbidity from therapeutic abortio n. After adjusting for demographic and obstetric factors, the differen ce in preferences for early vs late prenatal diagnosis was an independ ent predictor of the choice of chorionic villus sampling in a multivar iate model. Among women whose decision analyses selected amniocentesis , 56.8% had chosen amniocentesis, and among women whose analyses selec ted chorionic villus sampling, 63.2% had chosen chorionic villus sampl ing (p = 0.05). We conclude that the preferences of pregnant women for the outcomes of prenatal testing were associated with their choice of amniocentesis or chorionic villus sampling. In addition, the choice o f prenatal test made by the majority of women was concordant with that of a decision-analytic model that incorporated their preferences. Nev ertheless, because many women made choices that were discordant with t heir decision-analytic results, further research into the bases for th eir choices is warranted.