Determinants of delayed early childhood development among children under three years of age in South West Shewa Zone, Ethiopia: a case–control study

Developmental delay is characterized by a child’s inability to reach key developmental milestones within the expected age range. The first three years of life represent a critical period for brain growth and development, establishing the foundation for long-term health, cognitive function, and overall well-being. Delays in achieving developmental milestones can significantly hinder a child’s potential, with broader implications for communities and society. Hence, this study aimed to identify the determinants of developmental delay among children under three years of age attending public hospitals in South West Shewa Zone, Ethiopia. An institution-based unmatched case‒control study was conducted among 309 (103 cases and 206 controls) children. This study was conducted from November 1, 2024, to February 28, 2025. Cases were children diagnosed with developmental delay based on a clinical developmental assessment. Controls were children without delay, confirmed by age-appropriate milestone achievement on clinical evaluation. Eligible cases and controls were selected using systematic random sampling, and interviewer-administered questionnaires were used to collect the data. The collected data were entered into EpiData and analyzed using SPSS software. Binary logistic regression analyses were conducted, and statistically significant associations were determined on the basis of the AOR, with a 95% CI and a p value of < 0.05. This study revealed that children living in rural areas (AOR = 3.04; 95% CI: 1.645–5.625), those from large families( ≥ 5 members) (AOR = 2.5; 95% CI: 1.23–4.35), preterm births (< 37 weeks) (AOR = 4.00; 95% CI: 1.93–8.27), children with a history of illness in the past six months (AOR = 3.34; 95% CI: 1.76–6.29), and obstetric complications during labor (AOR = 2; 95% CI: 1.05–4.01) were significantly associated with childhood developmental delay. This study identified place of residence, family size, gestational age at birth, a child’s history of illness in the past six months, and maternal obstetric complications during labor as significant factors associated with childhood developmental delay. Hence, targeted developmental screening should be prioritized for children born preterm, those with a history of recent illness, and those whose mothers experienced obstetric complications. In addition, rural families and large households require extra support for early childhood stimulation and nutrition.