Current Evidence of the Effect of Breastfeeding on Ear Molding Outcomes: A Scoping Review

OBJECTIVE: To provide an overview on auricular molding and to investigate whether breastfeeding is associated with greater cartilage malleability or improved perinatal auricular molding outcomes. DATA SOURCES: Embase, MEDLINE, and CENTRAL databases. METHODS: Three databases were comprehensively searched for treatment of congenital auricular malformations or deformations with auricular molding. Extracted data included study design, patient demographics and auricular anomalies, interventions and outcomes measures, and references to the effect of estrogen and breastfeeding on cartilage malleability and ear molding. RESULTS: Out of 1018 unique articles, 67 were included in this review. The articles included a total of 3645 patients and 5384 ears, of which helical rim abnormality (20.6%), lop/lidding/cup ear (20.2%), and prominent ear (11.1%) were the most represented. Of the 67 articles referencing estrogen levels, 49 supported the claim that estrogen increases auricular cartilage malleability. Fifteen articles (22.4%) referenced the effect of breastfeeding on infant circulating estrogen levels and molding outcomes, while 8 (53.3%) of those articles supported the claim. Notably, only 4 primary sources were referenced regarding the effect of breastfeeding among all reviewed literature. CONCLUSIONS: There is insufficient evidence to suggest that breastfeeding leads to increased circulating estrogen levels in infants, increased auricular cartilage malleability, or improved ear molding outcomes. The direct impact of hyaluronic acid on the mechanical properties of auricular cartilage in vivo remains unclear.