Objective Our aim was to determine the effects of fetal exposure to propoxur and pyrethroids, on child neurodevelopment at 2 years of age. Patients and Methods Mothers were prospectively recruited during mid-pregnancy in Bulacan, Philippines where multiple pesticides including propoxur, cyfluthrin, chlorpyrifos, cypermethrin, pretilachlor, bioallethrin, malathion, diazinon and transfluthrin are used. To detect prenatal exposure to these pesticides, maternal hair and blood, infant’s hair, cord blood, and meconium were analyzed for the pesticides by gas chromatography/mass spectrometry. Infants were examined at 2 years of age with 95.1% follow up rate and their neurodevelopment outcome was assessed by the Griffiths Mental Developmental Scale (N=754). Results Meconium analysis was the most sensitive method to detect fetal exposure to pesticides and exposure was highest for propoxur (21.3%) and the grouped pyrethroids (2.5% - bioallethrin, transfluthrin, cyfluthrin and cypermethrin). Path analysis modeling was performed to determine the effects of fetal exposure to propoxur and pyrethroids on the child’s neurodevelopment at 24 months of age while controlling for confounders. Only singletons and those with complete data for the path analysis were included (N=696). Using a path analysis model, there was a significant negative (β= −0.14, p<0.001) relationship between prenatal pesticide exposure to propoxur and motor development at 2 years of age after controlling for confounders, e.g., infant gender, socioeconomic status, maternal intelligence, home stimulation (HOME), postnatal exposure to propoxur and blood lead level at 2 years of age. Conclusion At 2 years of age, prenatal exposure to propoxur was associated with poorer motor development in children.

Background There is a need to assess neurobehavioral performance of children in developing countries using standardized developmental tools. Methods The Griffiths Mental Development Scales was evaluated in the Philippines by comparing the performance of 742 Filipino children longitudinally at 6, 12 and 24 months old to those of their British counterparts. Results The mean general and subquotient scores of Filipino children were all within average for age. Comparison with British children showed that except for performance subscales, Filipino children had significantly higher developmental subquotients at 6 months old. As the Filipino infants grew older, their developmental subquotients in all subscales were significantly lower, except for personal and social skills at 24 months old. The genetic predisposition as evidenced by modest maternal scores on the Wechsler Intelligence Scales and lack of familiarity with test materials are factors that may influence the developmental patterns of Filipino children. Conclusion Although the performance of the Filipino children in the Griffiths test were within average with age, their performance on developmental subquotients at later ages of 12 and 24 months were significantly lower than British children and may have been influenced by differences in ethnicity, cultural traditions and limited environmental resources.