title: Chorion villus sampling and limb deficiency--cause or coincidence?
abstract: 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.
authors.affiliation: Cambridge University Department of Medical Genetics, Addenbrooke's Hospital, U.K.
authors.forename: H
authors.initials: H
authors.lastname: Firth
mesh_terms: D015193:Chorionic Villi Sampling / Q000009:adverse effects*; D005121:Extremities / Q000196:embryology; D005260:Female; D005865:Gestational Age; D006801:Humans; D017880:Limb Deformities, Congenital / Q000453:epidemiology / Q000209:etiology*; D011247:Pregnancy