Racial-ethnic differences in prenatal diagnostic test use and outcomes: Preferences, socioeconomics, or patient knowledge?

Objective: To determine whether use of chorionic villus sampling and amniocentesis varies by racial-ethnic group and, if so, whether this variation is reflected in the prevalence of Down syndrome-affected births to women age 35 and older, the ages at which prenatal diagnosis is offered currently. Methods: Medical charts of 238 women 35 years of age and older presenting for care at the University of California at San Francisco by 20 gestational weeks in 1993 and 1994 were reviewed to assess prenatal diagnostic test use. The prevalence of Down syndrome-affected births in California during 1983-1991 was obtained from the Birth Defects Monitoring Program. Results: Latinas and African-American women were much less likely to undergo prenatal diagnosis than were whites and Asians. Odds ratios (OR) and 95% confidence intervals (CI), with white women serving as the reference group, were as follows: Asians 1.16 (0.57-2.36), Latinas 0.19 (0.08-0.43), and African-Americans 0.19 (0.07-0.49). Trends persisted, at diminished magnitude, after adjustment for socioeconomic characteristics: OR for Asians 1.77 (0.78-3.98), Latinas 0.28 (0.09-0.83), and African-Americans 0.33 (0.10-1.10). Non-white women age 35 and older were significantly more likely than white women to give birth to a Down syndrome-affected infant: risk ratios for Asians 1.81 (1.61-2.03), Latinas 3.00 (2.74-3.28), and African-Americans 1.86 (1.63-2.11). Conclusion: Racial-ethnic differences exist in prenatal diagnostic test use and associated outcomes in women age 35 and older. Socioeconomic factors are partially responsible; patient education and preferences may play a role.