Morris J K, Mutton D E, Ide R, Alberman E, Bobrow M
Department of Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Medical College of St Bartholomew's Hospital, United Kingdom.
J Med Screen. 1994 Oct;1(4):233-7. doi: 10.1177/096914139400100410.
The national register of chromosomal anomalies that lead to Down's syndrome has enabled the monitoring of change in prenatal diagnosis for this condition, and the factors which affect the change. The proportion of cases of cytogenetically diagnosed Down's syndrome in England and Wales detected prenatally rose to 46% in 1991-2 from 31% in 1988-9, a 1.5-fold increase (95% confidence interval 1.3 to 1.7). The increase was confined to mothers under 40 years and was due to the introduction of screening by maternal serum analysis and ultrasound. Over a quarter of affected pregnancies in women aged 25-29 were detected prenatally in 1991-2 compared with less than 10% in 1988-9. Analysis of the data showed regional differences in prenatal diagnosis rates, and in the length of time elapsing between the diagnostic test and termination of an affected pregnancy. An inexplicable finding was that this period varied with the sex of the fetus, being on average a day longer for females than for males.
全国染色体异常导致唐氏综合征登记册有助于监测针对该病症的产前诊断变化情况以及影响这种变化的因素。在英格兰和威尔士，经细胞遗传学诊断的唐氏综合征病例中，产前检测出的比例从1988 - 1989年的31%升至1991 - 1992年的46%，增长了1.5倍（95%置信区间为1.3至1.7）。这一增长仅限于40岁以下的母亲，原因是引入了母体血清分析和超声筛查。1991 - 1992年，25至29岁女性中超过四分之一的受影响妊娠在产前被检测出来，而1988 - 1989年这一比例不到10%。数据分析显示，产前诊断率以及诊断测试与受影响妊娠终止之间的时间间隔存在地区差异。一个无法解释的发现是，这段时间因胎儿性别而异，女性平均比男性长一天。
