Among 289 pregnancies in which chorion villus sampling (CVS) was carried out at 56-66 days' gestation, 5 babies with severe limb abnormalities were subsequently identified. 4 had oromandibular-limb hypogenesis syndromes, and the other had a terminal transverse limb reduction defect. This high incidence raises the possibility that CVS was an aetiological factor for these developmental anomalies.