Renal ultrasonography not required in babies with isolated minor ear anomalies.

Aim: To determine whether infants with isolated minor anomalies of the external ear are at increased risk of renal malformations.

Methods: Consecutive infants with isolated minor anomalies of the external ear (preauricular skin tags, preauricular sinuses, ear pits, and misshapen pinnae) were offered renal ultrasonography by experienced sonographers over a 41 month period. The prevalence of renal anomalies in such infants was compared with that detected on routine fetal scanning during the same period.

Results: Ninety six of 13 136 liveborn infants (7.3/1000, 95% confidence interval (CI) 5.9 to 8.9) were noted to have isolated minor ear anomalies on routine neonatal examination, with preauricular skin tags being the most common (85%). Ninety one (95%) infants underwent renal sonography at a mean (SD) age of 40 (19.6) days. Only one infant (1.1%, 95% CI 0.03 to 5.9) had transient unilateral pyelectasia. During the same period, non-syndromic renal anomalies were found in 0.64% (95% CI 0.52 to 0.73) of infants, a prevalence no different from that of infants with minor ear anomalies (p = 0.44).

Conclusions: Routine renal imaging is not warranted in infants with such minor external ear anomalies unless accompanied by other systemic malformations.