Firth H
Cambridge University Department of Medical Genetics, Addenbrooke's Hospital, U.K.
Prenat Diagn. 1997 Dec;17(13):1313-30.
Chorion villus sampling (CVS) is a widely used technique in first trimester prenatal diagnosis. In the early 1990s, two clusters of babies with limb defects following CVS were reported, raising the possibility of a causal association between early CVS and transverse limb deficiency. The evidence for this association is reviewed and shows a diminishing risk for transverse limb deficiency with advancing gestation. The risk of limb deficiency extends through the period of limb morphogenesis and slightly beyond; falling from levels 10-20-fold above background at nine weeks and below, to levels approaching (or only a few-fold above) background at 11 weeks and beyond.
绒毛取样（CVS）是孕早期产前诊断中广泛应用的一项技术。20世纪90年代初，有报告称两群接受绒毛取样后的婴儿出现肢体缺陷，这增加了早期绒毛取样与横向肢体缺损之间存在因果关联的可能性。本文对这种关联的证据进行了综述，结果显示随着孕周增加，横向肢体缺损的风险逐渐降低。肢体缺损的风险贯穿肢体形态发生期，并稍有超出；从孕9周及以下高于背景水平10至20倍，降至孕11周及以后接近背景水平（或仅高于背景水平几倍）。
