Pre-auricular tags and pits in the newborn: The role of renal ultrasonography

Objective: To determine the role of renal ultrasonography in the evaluation of healthy newborn infants with isolated pre-auricular tags and pits. Study design: During the 4 years of prospective study, 108 of 17,286 infants were born with isolated pre-auricular tags or pits (6.2 per 1000 live births): 92 were assessed for urinary tract abnormalities by performing renal ultrasonography at 1 to 3 months of age. The study group was compared with a control group of 95 consecutive healthy infants without pre-auricular tags or pits born during the same period who underwent renal ultrasonography on the second day of life. Results: The study and control groups were comparable in birth weight, gestational age, and sex ratio. Renal ultrasonography was abnormal only in 2 infants with pre-auricular tags (2.2%); both had mild left pyelectasis. The prevalence did not differ significantly from that in the control group, in which 3 infants had mild pyelectasis (3.1%, P = 1.0) and 1 infant had a renal calculus. The prevalence of renal abnormalities in infants with isolated pre-auricular tags or pits in our study (2.2%) was also comparable to the prevalence in the general population (all abnormalities 0.2%-8.1%; significant abnormalities 0.2%-1.4%). Conclusions: We conclude that renal ultrasonography is not indicated in the routine evaluation of the newborn infant with isolated pre-auricular tags or pits.