Duration of breastfeeding and psychomotor development in 1-year-old children – Polish Mother and Child Cohort Study

Objectives The objective of this study was to evaluate the association between breastfeeding duration and child neurodevelopment based on the Polish Mother and Child Cohort Study. Material and Methods The current analysis included 501 mother–child pairs. The analysis evaluating the association between the length of breastfeeding and child neurodevelopment considered the following variables: maternal age and body mass index, weight gain during pregnancy, parental level of education, marital status, socioeconomic status, child gender, birthweight, type of delivery, preterm delivery, pre- and postnatal exposure to tobacco constituents and child day care attendance. Psychomotor development was assessed in 1-year-olds on the Bayley Scales of Infant and Toddler Development . Results The length of breastfeeding correlated positively with maternal age at delivery (ρ = 0.13), maternal and paternal level of education (ρ = 0.2 and ρ = 0.14 respectively), birthweight (ρ = 0.1) and marital status (ρ = 0.16) (p < 0.05). A negative correlation between the length of breastfeeding and maternal smoking status during the first year after delivery (ρ = –0.19) and weight gain during pregnancy (r = –0.1) was observed (p < 0.05). The association between the duration of breastfeeding and child development was not statistically significant in the model with the inclusion of confounding variables. A significant association between language development and maternal level of education (p = 0.004), gender of the child (p = 0.0007) and maternal weight gain during pregnancy (p = 0.01) was found. A negative association between cognitive development and maternal salivary cotinine during pregnancy (p = 0.03) and a negative association between motor development and maternal smoking status during the first year after delivery (p = 0.007) were also found. Conclusions This study found no significant association between the duration of breastfeeding and child development after adjustment for confounders. Int J Occup Med Environ Health. 2019;32(2):175–8