Source: Adapted from C. A. Huether et al., Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and Metropolitan Atlanta, 1970-1989, Journal of Medical Genetics 35: 482-90 (1998). Figure 8.20B Maternal age and incidence of Down syndrome
-Which conclusion can best be drawn from this study?
A) Women of age 20 or younger never have a child with Down syndrome.
B) Women in this study who were 45 years old had three times the incidence of babies with Down syndrome as did 40-year-old women.
C) Many babies with Down syndrome die before birth.
D) For 40-year-old women around the world, ten births per thousand have Down syndrome.

Question

Source: Adapted from C. A. Huether et al., Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and Metropolitan Atlanta, 1970-1989, Journal of Medical Genetics 35: 482-90 (1998). Figure 8.20B Maternal age and incidence of Down syndrome
-Which conclusion can best be drawn from this study?
A) Women of age 20 or younger never have a child with Down syndrome. 
B) Women in this study who were 45 years old had three times the incidence of babies with Down syndrome as did 40-year-old women. 
C) Many babies with Down syndrome die before birth. 
D) For 40-year-old women around the world, ten births per thousand have Down syndrome.

Quizplus · Accepted Answer

According to the figure, 45-year-old women had a Down syndrome incidence rate of approximately 30 per 1,000 live births, while 40-year-old women had a rate of approximately 10 per 1,000 live births. Therefore, the incidence of Down syndrome among babies born to 45-year-old women in this study was three times higher than that of babies born to 40-year-old women. None of the other answer choices can be supported by the information in the figure.