Gender-specific effects of exposure to maternal prenatal smoking on gross motor skills and movement behaviors in 3-5 year-old children

Background Smoking during pregnancy has been associated with various health and behavioral problems in offspring throughout their lifespan. In addition, studies have shown that these health and behavioral problems following maternal prenatal smoking exposure (MPSE) are likely sex-dependent, i.e. the outcomes are divergent between male and female offspring. However, studies on whether MPSE affects gross motor skills in 3-5 year-old children in a sex-specific manner are lacking. The first aim of this project is to examine the effects of MPSE on gross motor skills in 3-5 year-old boys and girls. The second aim is to identify factors that are associated with gross motor skills in children with MPSE. Methods The data used in this project are from the 2012 National Youth Fitness Survey (NNYFS) conducted by the Centers for Disease and Prevention National Center for Health Statistics (NCHS). Out of the 368 children aged 3-5 surveyed by NCHS, 329 (N = 34 with MPSE) had locomotor skills standard score (LSSS), object control skills standard score (OCSSS), and gross motor quotient (GMQ) along with demographic data, body measurement data early childhood questionnaire data movement behavior questionnaire data and were selected for this study. Results Boys with MPSE had significantly lower LSSS, OCSSS, and GMQ compared to those without MPSE, while no significant differences in LSSS, OCSSSS, and GMQ for girls were detected, indicating a sex-specific effect of MPSE on GMQ in 3-5 year-old children. MPSE was associated with low ratio of family income to poverty (RFIP) in girls but not in boys, suggesting a sex-specific inverse relationship of MPSE with parity. MPSE was associated with having no physical activity outside of school for the past 7 days in boys but not in girls, watching TV for > 2 h in the past 30 days and having 2 or fewer days with physical activity at least 60 min in the past 7 days in girls but not in boys, suggest that MPSE is associated with movement behaviors that confer less physical activity in boys and more sedentary state in girls. Conclusion MPSE negatively impacts gross motor skills in 3-5 year-old boys.