The Fetal Effects of Chorionic Villus Sampling

BACKGROUND: Physical examinations have been essential in the delineation of the spectrum of teratogenic effects of teratogens, such as valproate, isotretinoin and thalidomide, as well as chorionic villus sampling (CVS). CVS became an alternative to amniocentesis in the 1980s, because results were provided earlier in pregnancy. In 1991, a dramatic report of 5 CVS-exposed infants, out of 289 exposed, with severe limb and craniofacial defects raised the question of a significant risk, particularly when the procedure was carried out before 70 days of gestation. Some epidemiologic studies using data from birth defects registries showed an increase in the number of CVS-exposed infants with limb reduction defects and others did not. However, case reports of physical examination findings showed a wider range of abnormalities, including hypoplasia of two or three fingers or toes in CVS-exposed children as well as terminal transverse limb defects with nubbins. In addition, hemangiomas were found to be a common non-limb malformation in CVS-exposed children. METHODS: Presented here are the findings from a case-control study of 38 CVS-exposed and 41 unexposed, matched children. RESULTS AND CONCLUSIONS: The physical examinations identified a spectrum of abnormalities from terminal transverse limb defects with nubbins to hypoplastic, shortened or stiff fingers and toes with small or absent nails.