Iselius L, Lindsten J
Hum Genet. 1986 Feb;72(2):133-9.
A continuous increase in the incidence of Down syndrome in Sweden was noted during 1979-1981. This increase mainly occurred among children of younger mothers and was more pronounced for the males than for the females. There was no evidence of a significant seasonal variation, increased frequency of prematurely born children, or decrease in the number of cases aborted after prenatal diagnosis. An analysis of the whole 15-year period indicates that the incidence of Down syndrome has increased slowly in both sexes, and that there might have been a superimposed cyclic variation limited to the males.
1979年至1981年期间，瑞典唐氏综合征的发病率持续上升。这种上升主要发生在年轻母亲所生的孩子中，且男性比女性更为明显。没有证据表明存在显著的季节性变化、早产儿童频率增加或产前诊断后流产病例数减少。对整个15年期间的分析表明，唐氏综合征的发病率在两性中均缓慢上升，并且可能存在仅限于男性的叠加周期性变化。
