ML Tang

Abstract

Objective: To investigate the relationship between environmental tobacco smoke (ETS) exposure during prenatal and early childhood period and developmental delay among Hong Kong Chinese toddlers. Methods: A case-control study was carried out on 392 children with newly diagnosed developmental delay and 393 controls with normal development. A self-administered questionnaire was used to collect household smoking history. The main outcome measures were the adjusted odds ratios for developmental delay in different ETS exposures during prenatal and postnatal period. Results: Before adjustment, household ETS appeared to be associated with elevated rates of developmental delay among toddlers, before and after birth (crude ORs = 1.53 [95%CI 1.13-2.07] & 1.44 [95%CI 1.06-1.96] respectively). The main contribution was from paternal smoking (crude ORs = 1.73 [95%CI 1.24-2.42] & 1.90 [95%CI 1.34-2.68] respectively). However, these associations became non-significant statistically when the child's gender and socioeconomic factors of the family were adjusted (adjusted ORs = 1.18 [95%CI 0.86-1.63] & 1.23 [95%CI 0.88-1.73] respectively). Conclusion: There is some evidence of an association between environmental tobacco smoke in both prenatal and early childhood period and developmental delay among Hong Kong Chinese toddlers. However, this association appears to be confounded by gender of the child and socioeconomic factors. However, since home is the most significant ETS exposure location for toddlers, educational efforts for family members about reducing their children's ETS exposure are essential.