Continuities in maternal substance use from early adolescence to parenthood: findings from the intergenerational cohort consortium.

BACKGROUND: This study assessed the extent to which women's preconception binge drinking, tobacco use and cannabis use, reported prospectively in adolescence and young adulthood, predicted use of these substances during pregnancy and at 1 year postpartum. METHODS: Data were pooled from two intergenerational cohort studies: the Australian Temperament Project Generation 3 Study (395 mothers, 691 pregnancies) and the Victorian Intergenerational Health Cohort Study (398 mothers, 609 pregnancies). Alcohol, tobacco and cannabis use were assessed in adolescence (13-18 years), young adulthood (19-29 years) and at ages 29-35 years for those transitioning to parenthood. Exposures were weekly or more frequent preconception binge drinking (5 + drinks in one session), tobacco use and cannabis use. Outcomes were any alcohol, tobacco and cannabis use prior to awareness of the pregnancy, after awareness of pregnancy (up to and including the third trimester pregnancy) and at 1 year postpartum. RESULTS: Frequent preconception binge drinking, tobacco use and cannabis use across both adolescence and young adulthood were strong predictors of continued use post-conception, before and after awareness of the pregnancy and at 1 year postpartum. Substance use limited to young adulthood also predicted continued use post-conception. CONCLUSIONS: Persistent alcohol, tobacco use and cannabis use that starts in adolescence has a strong continuity into parenthood. Reducing substance use in the perinatal period requires action well before pregnancy, commencing in adolescence and continuing into the years before conception and throughout the perinatal period.

Lifetime cannabis exposure and small airway function in a population-based cohort study.

Background and objective: The long-term effects of cannabis on small airway function remain unclear. We investigated associations between cannabis use and small airway function in a general population sample. Methods: Cannabis use was ascertained at multiple ages from age 18 to 45 years and quantified as joint-years among 895 participants in the Dunedin Multidisciplinary Health and Development Study. Small airway function at ages 38 and 45 years was measured using impulse oscillometry (IOS) before and after inhalation of salbutamol. Analyses used multiple linear regression adjusting for tobacco use, body mass index and height. Longitudinal analyses of cannabis use between 38 and 45 years also adjusted for IOS at age 38 years. Results: Associations between lifetime cannabis joint-years and IOS differed between men and women: in women, cannabis use was associated with pre-bronchodilator resistance at 5 Hz (R 5) and 20 Hz (R 20), reactance at 5 Hz, area of reactance and resonant frequency, and marginally associated with the difference between R 5 and R 20. Cannabis use was only statistically significantly associated with pre-bronchodilator resonant frequency in men. Cannabis use between the ages of 38 and 45 years was associated with a similar pattern of changes in IOS measures. After salbutamol, cannabis use was only statistically significantly associated with R 5 and R 20 among women and none of the IOS measures among men. Conclusions: Cannabis use is associated with small airway dysfunction at age 45 years, indicating an increase in peripheral airway resistance and reactance. These associations were greater and mostly only statistically significant among women. Associations were weaker and mostly nonsignificant after bronchodilator use, suggesting that cannabis-induced changes in small airways may be at least partially reversible.

Randomized controlled trial of a web-based primary care intervention for multiple health risk behaviors.

BACKGROUND: Physical inactivity, low fruit and vegetable intake, hazardous drinking, and smoking are leading risk factors for disease and injury. The aim of this study was to obtain estimates of efficacy in reducing the first three of these behaviors. METHOD: The design was a randomized controlled trial: 218 patients (17-24 years) attending a student health service at a New Zealand university in 2003 were assigned to: (A) web-based assessment and personalized feedback (n = 72); or (B) assessment only (n = 74); or (C) minimal contact (n = 72). Outcome measures were the proportion meeting recommendations for fruit and vegetable consumption, physical activity, and alcohol consumption 6 weeks later. RESULTS: Follow-up assessments were attained for 86% of participants, with no evidence of differential attrition. There were significant differences in the proportion meeting recommendations for fruit and vegetable consumption and physical activity in group A relative to C. Hazardous drinking prevalence did not vary significantly by group. CONCLUSIONS: Differences appear attributable to the intervention. The intervention could be routinely provided in primary care, and its efficacy could be assessed in a large randomized controlled trial.