• 1 January 1981
    • journal article
    • research article
    • Vol. 58 (3), 282-285
Abstract
Estimates are made of the rates of all clinically significant cytogenetic abnormalities in live births by 1 yr maternal age intervals ranging from ages 15-49. Downs syndrome results from the most prevalent clinically significant cytogenetic abnormality, yet the rates of disorders associated with other cytogenetic abnormalities also increase with maternal age and significantly contribute to the overall rate at the older ages. The estimated rate of all clinically significant cytogenetic abnormalities rises from about 2/1000 (1/500) at the youngest maternal ages to about 2.6/1000 (1/270) at age 30, 5.6/1000 (1/180) at age 35, 15.8/1000 (1/60) at age 40, and 53.7/1000 (1/20) at age 45.