Pattern analysis for ultrasound anomalies in fetuses with normal karyotype.

Two hundred cases of double or multiple anomalies (up to five in the same fetus) out of 828 karyotypically normal fetuses with at least one ultrasound finding were enrolled in the present study. One hundred and sixty patterns belonging to 200 fetuses were found. Then, we included in the final analysis only those double or triple patterns of anomalies with frequency more then 1. Thus, 123 cases and 83 patterns were analyzed. A double pattern was intended as any combination of ultrasound findings present in the same fetus. Exact Chi-square test was used to evaluate the specificity of the association of the most frequent patterns. The association of patterns was expressed as ratio between observed and expected frequency (O/E) ratio. Pattern analysis was used as statistical tool to calculate the number of possible associations of ultrasound finding. Anomalies of fluid distribution, as well as Central Nervous System malformations, and facial malformations were among the most significant associations. Among the triple patterns, Cleft Lip + Cleft Palate + Holoprosencephaly showed the highest degree of association. Antenatal diagnosis of ultrasound finding can benefits by considering the present results.