Dr Lindsey Hines

Lindsey A. Hines completed her PhD in Psychiatric Epidemiology (National Addiction Centre, King’s College London) and is a Sir Henry Wellcome Postdoctoral Fellow in Population Health Sciences at the University of Bristol, UK. Her research expertise is in the epidemiology of drug use, with a focus on the causes and consequences of use during adolescence. Her fellowship explores the pathways between early life experiences, frequent drug use in adolescence, and mental health problems in later life. By conducting complex causal inference analysis of large, longitudinal cohorts, she aims to produce work with practical utility for informing mental health intervention.

Cannabis and tobacco use prior to pregnancy, and relationship to subsequent offspring birth outcomes: a 20-year intergenerational prospective cohort study

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Prenatal tobacco and cannabis use are risk factors for adverse birth outcomes. However, little attention has been paid to the relationship between tobacco or cannabis use at ages prior to conception and birth outcomes.

In a prospective intergenerational cohort study, over 1000 offspring were born to 662 parents (aged 29 and over). The parent’s substance use had been prospectively measured from adolescence to young adulthood. Frequency of parental substance use between age 15 and 29 were assessed for association with offspring birth outcomes of pre-term birth, low birth weight, and foetal growth restriction.

Preconception parent daily cannabis use at age 15-17 was associated with four times the likelihood of offspring being born pre-term and low birth weight. After adjustment for other factors, offspring remained at increased likelihood of being born pre-term. Preconception parent daily tobacco use at age 29 was associated with twice the likelihood of offspring being born small for gestational age after adjustment other factors, but this relationship was attenuated by adjustment for antenatal tobacco/cannabis exposure.

Parent’s daily use of cannabis between age 15-17 may embed risk for offspring pre-term birth. Reducing this behaviour could reduce the risk of pre-term birth by 11%. Replication in larger, pooled intergenerational samples is essential to strengthen evidence.

National Health and Medical Research Council (Australia); The Wellcome Trust (UK); Australian Government.