Children's gifts

The ALSPAC study team has followed around 14 000 children and their parents from before birth. The children are now around 13–14 years old. Throughout this time, detailed information has been gathered about their health and lifestyle. The cohort's size, and the range of information gathered, means that many health-related associations can be explored.

Exposure to mercury is known to affect childhood cognitive development and early motor skills. There have been fears that thimerosal – a mercury-containing preservative used in some children's vaccines – might harm young children. Use of ALSPAC data, however, revealed no link between exposure to thimerosal and poor cognitive performance. [Heron J et al. Pediatrics 2004;114(3):577–83.].

In another ALSPAC analysis, depression in fathers was associated with adverse emotional and behavioural outcomes in children aged 3.5 years, and an increased risk of conduct problems in boys. Paternal depression thus seems to have a specific and lasting effect on children's early development. [ Ramchandani P et al. Lancet 2005;365(9478):2201–5.]

Up to a third of people carry Neisseria meningitidis, but rates of invasive meningococcal disease are fairly low – possibly because of naturally acquired protective immunity. In ALSPAC children, salivary IgA levels against a range of meningococcal antigens increased with age, suggesting that IgA is important in host defence against meningococci. [Horton RE et al. Epidemiol Infect 2005;133(5):883–9.]

Bone mass in later life is related to birth weight, suggesting that the environment in the womb influences later bone development. In ALSPAC families, several aspects of maternal diet in pregnancy were linked to children's bone mass and other measures at age nine, suggesting that maternal diet is programming bone development in childhood (although the effect sizes are small). [Tobias JH et al. Osteoporos Int 2005 (in press).]

Paracetamol use in late pregnancy has been linked to an increased risk of early wheezing in offspring. Further work on the ALSPAC cohort confirmed that use of paracetamol, but not aspirin, in late pregnancy was associated with asthma. If the association is causal, as much as 7 per cent of childhood asthma could be put down to paracetamol exposure. [ Shaheen SO et al. Clin Exp Allergy 2005;35(1):18–25.]

ALSPAC is jointly funded by the Wellcome Trust and the Medical Research Council.