Impact of Consanguineous Marriage on Hearing Loss and Subsequent Speech and Language Delay in Under-Five Children: A Focused Case–Control Analysis

Abstract

Background: Parental consanguinity remains prevalent in South India due to socio-cultural practices. Although its association with congenital anomalies is established, its quantitative relationship with childhood hearing impairment and subsequent speech and language delay (SLD) requires regional evaluation. Objectives: The objective of the study was to quantify the association between parental consanguinity, hearing loss, and developmental speech/language delay among children under 5 years. Materials and Methods: A hospital-based case–control study was conducted in the Pediatric outpatient department in collaboration with ENT at Aarupadai Veedu Medical College and Hospital, Puducherry. Forty age- and gender-matched children were enrolled: 20 with parental consanguinity (Cases) and 20 without (Controls). Language development was assessed using the Language Evaluation Scale Trivandrum for children aged 1–3 years and the Trivandrum Developmental Screening Chart for those aged 3–5 years. Objective hearing assessment included Otoacoustic Emissions and Brainstem Auditory Evoked Responses. Results: SLD was identified in 14 (70.0%) Cases compared with 4 (20.0%) Controls (odds ratio [OR] 9.33, 95% confidence interval [CI]: 2.11–41.22; P = 0.0016). Hearing impairment was detected in 10 (50.0%) Cases versus 2 (10.0%) Controls (OR 9.00, 95% CI: 1.54–52.48; P = 0.0064). Expressive language delay was the predominant phenotype. Conclusion: Parental consanguinity was strongly associated with childhood hearing impairment and speech/language delay. These findings support integrating neonatal hearing screening and early language surveillance into primary healthcare, particularly in populations with prevalent consanguineous marriage practices.