A Morphometric Study of the Newborn Ear and an Analysis of Factors Related to Congenital Auricular Deformities.

Background: The incidence of neonatal ear deformities varies widely in the literature, and the incidence of those that correct spontaneously is largely unknown. To address these questions, the authors analyzed the auricles of 1500 newborns from the Pearl River Delta within the first 7 days of life and again at 30 days of age.

Methods: Using a combination of direct measurement and digital image measurement, the authors measured physiognomic ear length, physiognomic ear breadth, morphologic ear length, vertical distance between head and ear, and auriculocephalic angle of the newborns. The first measurement was within 1 week of birth, whereas the second measurement was performed for the same newborns 1 month after birth.

Results: Among 1500 newborns, 862 had various forms of auricular deformities. The incidence of neonatal auricular deformity in the Pearl River Delta area was 57.46 percent, and the self-healing rate was 31.55 percent by the 30-day follow-up. Seven factors were found to be statistically significant: mother's delivery situation, mother's hepatitis history, abnormal pregnancy, abnormal labor, cephalopelvic disproportion, premature rupture of membranes, and neonatal weight. Birth by cesarean delivery and mother with no abnormal pregnancy or no history of hepatitis were protective factors against the newborn's auricular deformity.

Conclusions: Newborns have a high incidence of auricular deformities, and different types of auricular deformities have distinct incidences. Auricular deformities are caused by the interactions of a number of factors. There were large differences in the self-healing rates of different types of auricular deformities.

Clinical Question/level Of Evidence: Risk, II.