Vocal Fold Immobility due to Birth Trauma: A Systematic Review and Pooled Analysis.

Objectives To describe the present understanding of birth trauma-related vocal fold immobility and quantitatively compare it with idiopathic congenital vocal fold immobility to explore whether it is a discrete entity. Data Sources PubMed, Ovid, and Cochrane databases. Review Methods English-language, observational, or experimental studies involving infants with idiopathic congenital or birth trauma-related vocal fold immobility were included. Data from these studies were pooled with our institution's vocal fold immobility database, with the resultant idiopathic congenital and birth trauma cohorts compared regarding patterns and outcomes of immobility. Results The search returned 288 articles, with 24 meeting inclusion criteria. Of studies reviewing all-cause immobility, 8 of 9 (88.9%) identified birth trauma as an etiology, although birth trauma definitions and proposed mechanisms of immobility varied. The study subjects, combined with our institution's database, yielded 188 idiopathic congenital and 113 birth trauma cases. Compared with idiopathic congenital cases, birth trauma cases had a higher proportion of unilateral immobility (72 of 113 [63.7%] vs 52 of 188 [27.7%], P < .001) and rate of resolution (41 of 51 [80.4%] vs 91 of 159 [57.2%], P = .003). Resolution occurred in 24 of 26 (91.3%) unilateral and 17 of 25 (68.0%) bilateral birth trauma cases and in 30 of 40 (75.0%) unilateral and 59 of 109 (54.1%) bilateral idiopathic congenital cases ( P = .11 and .20, respectively). Conclusion While the definition and mechanism of birth trauma-related vocal fold immobility warrant further investigation, these findings suggest that it is distinct from idiopathic congenital vocal fold immobility, with a unique presentation and potentially more favorable outcomes. This can inform counseling and management for infants with otherwise unexplained immobility but known birth trauma.