Maternal age and cognitive and behavioural outcomes in middle childhood

Abstract

The relationships between maternal age and childhood cognitive and behavioural outcomes were analysed in a birth cohort of New Zealand children studied until the age of 13 years. Increasing maternal age was associated with increasing scores on tests of cognitive ability and achievement and with decreasing reports of conduct problems. The correlations between maternal age and childhood cognitive/behavioural outcomes ranged from 0.11 to 0.21 with a median value of 0.18. These associations were adjusted statistically for the effects of maternal social background at the time of birth and for childhood history subsequent to birth. This analysis suggested that the poorer outcomes for children born to younger mothers reflected the cumulative effects of two sets of factors which placed these children at a disadvantage. Firstly, the offspring of younger mothers tended to be born into relatively poorly educated, socially disadvantaged families and secondly, these children were exposed to less nurturant and more changeable home environments. The net effects of differences in social background at birth and childrearing environments subsequent to birth were sufficient to explain most of the apparent correlation between maternal age and childhood cognitive/behavioural outcomes.

Association of prenatal maternal or postnatal child environmental tobacco smoke exposure and neurodevelopmental and behavioral problems in children.

“…Furthermore, ETS exposure during childhood may be more hazardous to neurodevelopment than in utero exposure to maternal smoking. Postnatal ETS exposure has also been associated with behavioral problems in all three studies that specifically examined behavior problems in children (31,32,40) and adequately controlled for home environment and other potentially intervening factors; two of these three studies (32,40), however, showed larger associations between behavioral problems and prenatal exposure to maternal smoke than with postnatal child ETS exposure. There are only three studies that investigated the relationship of maternal ETS exposure during pregnancy (28,36,38) and general cognitive performance, two of which were on the same cohort.…”

Effect of passive smoking on thyroid function in infants

“…As no significant influence of parental smoking on the development and growth of the children was observed, study of the effects of passive smoking on thyroid function should be extended to older children, in order to evaluate whether a relation exists between altered thyroid function and behavioural problems observed in children exposed to passive smoking (21,22). The clinical picture observed in adolescents exposed to passive smoking could be due to direct stimulation of sympathetic nervous activity induced by nicotine, superimposed upon the smoking-induced increase in thyroid hormone secretion (8).…”

The Relationship between Low Family Income and Psychological Disturbance in Young Children: An Australian Longitudinal Study

“…Due to growing reports suggesting a functional link between cigarette smoking and child behavioural disorders [60,61], degree of maternal cigarette smoking (smoker) during the first trimester of pregnancy was assessed at the first clinic interview utilising a smoking index in which number of cigarettes nominated as smoked per day by subjects was multiplied by the number of days per week subjects said they typically smoked. Subjects were classified into one of three categories of prenatal cigarette use as either: (i) non-smokers (65.2% of subjects); (ii) some/ moderate smokers (27.5% of subjects); or (iii) heavy smokers (7.3% of subjects).…”