This article is based on the study of 52 cases of Turner's syndrome, born between 1980 and 1996 and recorded in the Registry of Congenital Anomalies in the Canton of Vaud. In most cases the cytogenetic analysis was based on maternal multiple-marker screening, sonography findings or maternal age. The most common chromosome abnormality is complete monosomy X. The rare cases of mosaic and the one case of isochromosome mainly involve livebirths. Morphological analysis of foetuses revealed hygroma colli (84%) and hydrops (63%), frequently associated with major cardiac malformations. The livebirths present growth retardation, pterygium colli and facial dysmorphic features, but rarely complex malformations. In the light of our data, the probability of survival to birth is 0.8% and the prevalence in all clinical pregnancies is 1.1%.