Exposure to secondhand smoke (SHS) can affect fetal brain development as well as subsequent neurodevelopment. This study aimed to determine the association between prenatal and postnatal SHS exposure with children's neurodevelopment at 2years of age. Among 107 mother-child pairs from a Malaysia prospective cohort, prenatal and postnatal SHS exposure was determined based on maternal and child hair nicotine concentrations. Multiple linear regressions were used to determine the association between prenatal and postnatal levels of nicotine in maternal and children's' hair with children's neurodevelopment. After adjustment for confounders, prenatal nicotine concentration levels were negatively associated with communication (β=-2.059; p=0.015) and fine motor skills (β=-2.120; p=0.002) while postnatal nicotine concentration levels were inversely associated with fine motors (β=-0.124; p=0.004) and problem solving skills (β=-0.117; p=0.013). In conclusion, this study suggests that early life exposure to SHS may affect children's neurodevelopment.

Objectives The objectives of this study are to determine parental and children's hair nicotine levels, their relationships as well as to investigate the association of smoking status of the fathers with mothers' and children's hair nicotine. Methods A cross-sectional study design was conducted among 124 families who were participants of the Universiti Sains Malaysia Pregnancy Cohort Study. Both parents with their 2 years old children joined this study. A total of 92 hair samples of fathers, 124 hair samples of mothers and 111 hair samples of children were collected and analyzed by gas chromatography-mass spectrometry. Results Of total, 52.4 % of the fathers reported smoking. None of the mothers were smokers. Hair nicotine levels of fathers were found to be significantly correlated with mothers (r = 0.233, p = 0.026) and children (r = 0.508, p \ 0.001). Children living with smoking fathers had significantly higher median hair nicotine level compared to the children of non-smoking fathers (6.08 vs 0.22 ng/mg, p = 0.046). However, this association was not seen in the mothers. Quantile regression showed significant association between fathers' and children's hair nicotine. Conclusion There is a positive relationship between fathers' hair nicotine with mother's and children's hair nicotine. Living with smoking fathers can contribute to higher hair nicotine levels in children but not in mothers.

Along with the increasing overweight and obesity trends among adults and children globally, numerous studies have suggested a strong association between maternal overweight and obesity among their offspring. We sought to report the prevalence and associated factors of intergenerational overweight and obesity among mother–child pairs in Malaysia from 2006 to 2015. Data were analysed from three waves of the Malaysian National Health and Morbidity Survey, a population-based cross-sectional study conducted in 2006, 2011 and 2015. A mother and the youngest child from each household formed ‘mother–child pairs’ and were grouped according to their body mass index categories. A multivariable logistic regression model was performed to determine the factors associated with overweight mother/overweight child pairs (OWM/OWC), with normal weight mother/normal weight child pairs (NWM/NWC) as the reference group. The prevalence of OWM/OWC increased from 15.3% to 21.7%, while the prevalence of NWM/NWC decreased from 28.4% to 23.8% between 2006 and 2015. Older maternal age and having primary and secondary education levels were positively associated with OWM/OWC. Conversely, older child age, Chinese ethnicity, large household size and low-income households were inversely associated with OWM/OWC. In conclusion, intergenerational weight gain is a worrisome trend in Malaysia. These findings may help in guiding priority setting for obesity prevention strategies in Malaysia.

The transmission in intergenerational overweight and obesity (OW/OB) from mothers to their offspring has been widely explored in numerous studies. This phenomenon of OW/OB is a greater concern globally in particular among low-income households. However, studies conducted to determine the factors associated with OW/OB among mother-child pairs in low-income families are very scarce especially in Malaysia. Therefore, this study aimed to determine the prevalence trend and associated factors of overweight mothers and children in low-income households using the National Health and Morbidity Survey data between the years 2006 to 2015. In each low-income household, mother and child were identified and grouped as mother-child pairs based on their body mass index categories. Multivariable logistic regression was conducted to determine the factors associated with overweight mother/overweight child pairs (OWM/OWC) in low-income households. The reference group determined in the analysis was normal weight mother/normal weight child pairs (NWM/NWC). Within a decade, the transmission of OWM/OWC mother-child pairs in the low-income households has increased by 9.0%, while the prevalence of NWM/NWC decreased by 6.9%. In low-income households, older mothers and children aged between 10 to 14 years were significantly associated with OWM/OWC, while a larger household size and being as Chinese were less likely to become OWM/OWC. In conclusion, intergenerational obesity in mother and their offspring is showing an alarming trend among the lowest socio-economic group in Malaysia.