Warning signs for identifying neurodevelopmental disorders: a systematic literature review

OBJECTIVE: To synthesize the most consistent warning signs ("red flags") for NDDs: autism spectrum disorder, cerebral palsy, intellectual disability, language development disorder, coordination developmental disorder, attention deficit hyperactivity disorder, and global developmental delay. DATA SOURCE: Review in PubMed/Medline, Cochrane Library, SciELO, CAPES, and BVS, 2003-2025. Methodological quality was assessed with NOS, CASP, and AMSTAR. DATA SUMMARY: 54 studies were included. The most consistent early signs were grouped by NPMD domains: Motor: delay to sit ≥ 9 m, absence of independent walking 18 m, absence of pincer grasp 10 m, and asymmetrical motor patterns 12 m; Language: absence of babbling at 9-12 m, lack of words until 15-18 m, and absence of two-word combination 24 m; Social: absence of social smile, poor eye contact, deficits in shared attention and communicative gestures; Cognitive and behavioral: regression of skills, repetitive behaviors, absence of symbolic play, and irritability or inattention; Others: atypical sensory responses, sleep disturbances, and feeding difficulties. Instruments such as M-CHAT-R/F, ASQ, Bayley, and HINE increased the accuracy of screening and reduced referral delays. CONCLUSION: Early recognition of warning signs for NPMD disorder associated with complementary examinations and formal assessment should be integrated into routine pediatric care.