Published by Oxford University Press on behalf of the International Epidemiological Association © The Author 2009; all rights reserved.
Editorial |
Unravelling prenatal influences: the case of smoking in pregnancy
MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK.
E-mail: Barbara.Maughan@iop.kcl.ac.uk
| The first 150 words of the full text of this article appear below. |
The adverse health outcomes of maternal smoking in pregnancy are long-established: prenatal smoking retards fetal growth, depresses infant birthweight and is associated with increased risks of pregnancy loss.1 More recently, epidemiological evidence has also linked prenatal smoking with children's behavioural outcomes, and with impairments in their memory and learning. A quite extensive body of findings now documents increased risks of aggression, conduct problems and hyperactivity in the offspring of mothers who smoked while pregnant.2 Links with children's cognitive functioning are evident early in development, but may diminish with age. Associations with behavioural difficulties appear more long lasting, with some studies pointing to heightened risks of aggression and criminality persisting well into adult life.2
Do these observational findings reflect a causal influence? Identifying the causal status of environmental risk factors poses major challenges in many areas of epidemiological research;3 when those risks occur prenatally, the challenges can be especially acute.4 Three