Ear dysmorphism associated with cystic hygroma colli in second-trimester fetuses.

To investigate if fetuses with cystic hygroma colli have ear article dysmorphism, we studied 16 fetuses with cystic hygroma colli, all of which had 45,X karyotype, and 107 normal fetuses. All the specimens were second-trimester formalin-preserved human fetuses. The ear lengths and widths were measured and ear indices (length/width) calculated. There were no significant differences in the ear measurements of age-matched normal male and female fetuses (P > .05). Ear growth was less linear in the cystic hygroma colli group than in the normal fetuses; Pearson's coefficient .45 vs. .87 for ear length, and r = .77 vs. .88 for ear width. The mean (+/- SD) ear index of the normal fetuses was 1.56 +/- 0.22 compared to 2.10 +/- 0.36 of the cystic hygroma colli fetuses, P < .001. The ear dysmorphism (> 2 SD of gestational age norm) was observed in 6.3% (1/16) of the ear widths, 56.3% (9/16) of the ear lengths, and 62.5% (10/16) of the ear indices. We conclude that cystic hygroma colli fetuses with 45,X have unique ear auricle morphology.