Does maternal smoking during pregnancy predict the smoking patterns of young adult offspring? A birth cohort study.

Objective: To examine the association between maternal smoking during pregnancy and the development of smoking behaviour patterns among young adult offspring.

Method: Data were from the Mater-University of Queensland Study of Pregnancy (MUSP), a birth cohort of 7223 mothers and children enrolled in Brisbane, Australia, in 1981. The development of smoking behaviours (early or late onset, or combination of onset and prevalence patterns) among offspring at age 21 years with different patterns of maternal smoking (never smoked, smoked before or after pregnancy but not during pregnancy, or smoked during pregnancy) were compared. Maternal smoking information was derived from the prospectively collected data from the beginning of pregnancy until the child was 14 years of age. Analyses were restricted to the 3058 mothers and children whose smoking status was reported.

Results: The proportion of young adults who smoked regularly, either with early onset or late onset, was greater among those whose mothers had smoked during pregnancy compared with those whose mothers had never smoked. The smoking patterns among those adolescent offspring whose mothers stopped smoking during pregnancy, but who then smoked at other times during the child's life, were similar to those whose mothers had never smoked. This association was robust to adjustment for a variety of potential covariates.

Conclusions: The findings provide some evidence for a direct effect of maternal smoking in utero on the development of smoking behaviour patterns of offspring and provide yet another incentive to persuade pregnant women not to smoke.