Sleep-Disordered Breathing and Clinical Presentation in Infants with Congenital Laryngomalacia: A Polysomnographic Study

<b>Background/Objectives:</b> Congenital laryngomalacia (LM) is the most common cause of stridor in infants, presenting with a clinical spectrum that ranges from benign, self-limiting symptoms to severe airway obstruction. This study aimed to objectively characterize the type and severity of sleep-disordered breathing in infants with LM using polysomnography (PSG) and to correlate findings with LM subtypes, clinical presentation, and type of surgical intervention. <b>Methods:</b> A cohort of 42 infants diagnosed with LM (Type I: <i>n</i> = 14, Type II: <i>n</i> = 18, Type III: <i>n</i> = 10) underwent overnight PSG before surgical treatment. The Apnea-Hypopnea Index (AHI), Oxygen Desaturation Index (ODI), minimum and mean SpO₂, and heart rate were recorded. Clinical features (stridor, feeding difficulties, respiratory effort) and type of surgery (supraglottoplasty [S] or supraglottoplasty with epiglottopexy [S + E]) were analyzed across LM subtypes. <b>Results:</b> Baseline AHI was significantly higher in LM Type III (25.41 ± 6.95 events/h) compared with Type II (12.50 ± 5.05) and Type I (2.84 ± 1.96; <i>p</i> < 0.001). After surgery, AHI decreased to 1.76 ± 1.56 in Type III and 0.97 ± 0.70 in Type II. ODI showed a similar trend (Type III: 9.87 ± 5.99 before vs. 0.78 ± 0.69 after surgery; <i>p</i> < 0.001). Minimum SpO₂ increased from 69.50 ± 7.76% to 93.60 ± 1.82% in Type III (<i>p</i> < 0.001). Feeding difficulties were observed in 100% of Type III patients, compared with 83.3% of Type II and 42.9% of Type I patients. The distribution of apnea type differed significantly across groups (<i>p</i> < 0.001), with mixed obstructive-central apnea predominating in Type III. <b>Conclusions:</b> Polysomnography is an effective and objective tool for assessing LM severity and guiding surgical qualification. Increasing LM severity is associated with more pronounced PSG abnormalities, greater clinical burden, and a higher likelihood of requiring advanced surgical correction.