Macintosh M C, Wald N J, Chard T, Hansen J, Mikkelsen M, Therkelsen A J, Petersen G B, Lundsteen C
Academic Department of Reproductive Physiology, Obstetrics and Gynaecology, St. Bartholomew's Hospital Medical College, London, UK.
Br J Obstet Gynaecol. 1995 Oct;102(10):798-801. doi: 10.1111/j.1471-0528.1995.tb10845.x.
To estimate the fetal loss of Down's syndrome fetuses between the time of chorionic villus sampling (10 weeks gestation) and the time of amniocentesis (16 weeks gestation) and term in women aged 35 years and older.
The age specific prevalence rates in the first trimester of Down's syndrome were estimated using the Danish cytogenetic register in combination with results from four published studies. These were compared with the reported prevalence at the time of amniocentesis and at birth.
5927 singleton pregnancies undergoing chorionic villus sampling (71 cases of Down's syndrome and 5856 unaffected cases). This was combined with published data on a further 231 cases of Down's syndrome and 16,620 unaffected cases.
Age specific prevalences at the time of chorionic villus sampling. Proportion of pregnancies lost between the time of chorionic villus sampling and the time of amniocentesis and term.
Thirty-two percent of Down's syndrome pregnancies are lost between the time of chorionic villus sampling (10 weeks) and the time of amniocentesis (16 weeks) and 54% are lost by term.
The high fetal loss rates of Down's syndrome between the time of chorionic villus sampling and term introduce problems when evaluating first trimester screening tests with respect to their effective detection rates at term. A recommendation for quoting term risks is made.
评估35岁及以上孕妇中唐氏综合征胎儿在绒毛取样（妊娠10周）至羊膜穿刺术（妊娠16周）以及足月期间的胎儿丢失情况。
利用丹麦细胞遗传学登记册并结合四项已发表研究的结果，估算唐氏综合征孕早期的年龄特异性患病率。将这些数据与羊膜穿刺术时及出生时报告的患病率进行比较。
5927例接受绒毛取样的单胎妊娠（71例唐氏综合征病例和5856例未受影响病例）。这与另外231例唐氏综合征病例和16620例未受影响病例的已发表数据相结合。
绒毛取样时的年龄特异性患病率。绒毛取样至羊膜穿刺术及足月期间丢失的妊娠比例。
32%的唐氏综合征妊娠在绒毛取样（10周）至羊膜穿刺术（16周）期间丢失，54%在足月时丢失。
绒毛取样至足月期间唐氏综合征胎儿的高丢失率给评估孕早期筛查试验在足月时的有效检测率带来了问题。提出了引用足月风险的建议。
