Babak Khoshnood ^1*, Catherine De Vigan ¹, Véronique Vodovar ¹, Gérard Bréart ¹, François Goffinet ¹, Béatrice Blondel ¹

¹ INSERM U149

^* To whom correspondence should be addressed. E-mail: khoshnood{at}vjf.inserm.fr.

	Abstract

Objectives. We assessed socioeconomic differences in probabilities of prenatal diagnoses of Down syndrome and continuation of pregnancies after such diagnoses, along with the effects of these differences on disparities in live-birth prevalences of Down syndrome.

Methods. Using population-based data derived from 1433 cases of Down syndrome and 3731 control births, we assessed age-adjusted effects of maternal occupation and geographic origin on prenatal diagnoses, as well as overall and live-birth odds, of Down syndrome.

Results. Maternal occupation and geographic origin had significant effects on the probability of a prenatal diagnosis of Down syndrome and on continuation of pregnancy after such a diagnosis. Women in lower-status occupational categories had a higher likelihood of delivering a live-born infant with Down syndrome. In comparison with women in the highest-status occupational category, the age-adjusted odds ratio for a Down syndrome live birth among women without an occupation was 2.4 (95% confidence interval [CI]=1.7, 3.3). By contrast, there were no disparities in age-adjusted overall likelihood of Down syndrome.

Conclusions. Socioeconomic differences in use of prenatal testing have created disparities in the live-birth prevalence of Down syndrome. Overall Down syndrome risk does not vary according to socioeconomic status.

Key Words: Epidemiology, Birth Outcomes, Pregnancy, Screening, Socioeconomic Factors