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.

The Australian Temperament Project Generation 3 study: a population-based multigenerational prospective cohort study of socioemotional health and development.

PURPOSE: The Australian Temperament Project Generation 3 Study (ATPG3) was established to examine the extent to which offspring social and emotional development is shaped in the decades prior to conception, in parent and grandparent histories of psychosocial adjustment (eg, emotional regulation, relationship quality and prosociality) and maladjustment (eg, depressive symptoms, substance use and antisociality). PARTICIPANTS: The Australian Temperament Project (ATP) commenced in 1983 as a population representative survey of the social and emotional health of 2443 young Australians (Generation 2: 4-8 months old) and their parents (Generation 1). Since then, families have been followed from infancy to young adulthood (16 waves). Between 2012 and 2018, the cohort was screened biannually for pregnancies (Generation 3), with assessments conducted in the third trimester of pregnancy, and at 8 weeks and 1 year postpartum. FINDINGS TO DATE: A total of 1167 offspring (607 female) born to 703 Generation 2 parents (400 mothers) were recruited into the ATPG3 Study. Findings to date highlight: (1) strong continuities in depressive symptoms and substance use from adolescence through to becoming a parent; (2) a role for persistent preconception mental health problems in risk for parent-child bonding difficulties, as well as infant emotional reactivity and behaviour problems; (3) the importance of secure attachments in adolescence in reducing long-term risk for postpartum mental health problems; and (4) the protective nature of perceived social support, both preconception and postpartum, in strengthening relationship quality and social support during the COVID-19 pandemic. FUTURE PLANS: Assessments of ATPG3 families in preschool and middle childhood are currently funded and underway. We intend to maintain the offspring cohort through childhood, adolescence, young adulthood and into parenthood. Data will be used to map preconception determinants of emotional health, and enhance approaches to population monitoring and targeted intervention over the life course and across generations.

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

There is increasing evidence that the life-course origins of health and development begin before conception. We examined associations between timing and frequency of preconception cannabis and tobacco use and next generation preterm birth (PTB), low birth weight (LBW) and small for gestational age. 665 participants in a general population cohort were repeatedly assessed on tobacco and cannabis use between ages 14-29 years, before pregnancy. Associations were estimated using logistic regression. Preconception parent (either maternal or paternal) daily cannabis use age 15-17 was associated with sixfold increases in the odds of offspring PTB (aOR 6.65, 95% CI 1.92, 23.09), and offspring LBW (aOR 5.84, 95% CI 1.70-20.08), after adjusting for baseline sociodemographic factors, parent sex, offspring sex, family socioeconomic status, parent mental health at baseline, and concurrent tobacco use. There was little evidence of associations with preconception parental cannabis use at other ages or preconception parental tobacco use. Findings support the hypothesis that the early life origins of growth begin before conception and provide a compelling rationale for prevention of frequent use during adolescence. This is pertinent given liberalisation of cannabis policy.

The Victorian Intergenerational Health Cohort Study (VIHCS): Study design of a preconception cohort from parent adolescence to offspring childhood.

BACKGROUND: There is increasing evidence that parental determinants of offspring early life development begin well before pregnancy. OBJECTIVES: We established the Victorian Intergenerational Health Cohort Study (VIHCS) to examine the contributions of parental mental health, substance use, and socio-economic characteristics before pregnancy to child emotional, physical, social, and cognitive development. POPULATION: Men and women were recruited from the Victorian Adolescent Health Cohort (VAHCS), an existing cohort study beginning in 1992 that assessed a representative sample of 1943 secondary school students in Victoria, Australia, repeatedly from adolescence (wave 1, mean age 14 years) to adulthood (wave 10, mean age 35 years). METHODS: Victorian Adolescent Health Cohort participants with children born between 2006 and 2013 were recruited to VIHCS and invited to participate during trimester three, at 2 months postpartum, and 1 year postpartum. Parental mental health, substance use and socio-economic characteristics were assessed repeatedly throughout; infant characteristics were assessed postnatally and in infancy. Data will be supplemented by linkage to routine datasets. A further follow-up is underway as children reach 8 years of age. PRELIMINARY RESULTS: Of the 1307 infants born to VAHCS participants between 2006 and 2013, 1030 were recruited to VIHCS. At VIHCS study entry, 18% of recruited parents had preconception common mental disorder in adolescence and young adulthood, 18% smoked daily in adolescence and young adulthood, and 6% had not completed high school. Half of VIHCS infants were female (48%), 4% were from multiple births, and 7% were preterm (<37 weeks' gestation). CONCLUSIONS: Victorian Intergenerational Health Cohort Study is a prospective cohort of 1030 children with up to nine waves of preconception parental data and three waves of perinatal parental and infant data. These will allow examination of continuities of parental health and health risks from the decades before pregnancy to offspring childhood, and the contributions of exposures before pregnancy to offspring outcomes in childhood.

20-year outcomes in adolescents who self-harm: a population-based cohort study.

BACKGROUND: Little is known about the long-term psychosocial outcomes associated with self-harm during adolescence. We aimed to determine whether adolescents who self-harm are at increased risk of adverse psychosocial outcomes in the fourth decade of life, using data from the Victorian Adolescent Health Cohort Study. METHODS: We recruited a stratified, random sample of 1943 adolescents from 44 schools across the state of Victoria, Australia. The study started on Aug 20, 1992, and finished on March 4, 2014. We obtained data relating to self-harm from questionnaires and telephone interviews at eight waves of follow-up, commencing at mean age 15·9 years (SD 0·5; waves 3-6 during adolescence, 6 months apart) and ending at mean age 35·1 years (SD 0·6; wave 10). The outcome measures at age 35 years were social disadvantage (divorced or separated, not in a relationship, not earning money, receipt of government welfare, and experiencing financial hardship), common mental disorders such as depression and anxiety, and substance use. We assessed the associations between self-harm during adolescence and the outcome measures at 35 years (wave 10) using logistic regression models, with progressive adjustment: (1) adjustment for sex and age; (2) further adjustment for background social factors; (3) additional adjustment for common mental disorder in adolescence; and (4) final additional adjustment for adolescent antisocial behaviour and substance use measures. FINDINGS: From the total cohort of 1943 participants, 1802 participants were assessed for self-harm during adolescence (between waves 3 and 6). Of these, 1671 were included in the analysis sample. 135 (8%) reported having self-harmed at least once during adolescence. At 35 years (wave 10), mental health problems, daily tobacco smoking, illicit drug use, and dependence were all more common in participants who had reported self-harm during the adolescent phase of the study (n=135) than in those who had not (n=1536): for social disadvantage odds ratios [ORs] ranged from 1·34 (95% CI 1·25-1·43) for unemployment to 1·88 (1·78-1·98) for financial hardship; for mental health they ranged from 1·61 (1·51-1·72) for depression to 1·92 (1·79-2·04) for anxiety; for illicit drug use they ranged from 1·36 (1·25-1·49) for any amphetamine use to 3·39 (3·12-3·67) for weekly cannabis use; for dependence syndrome they were 1·72 (1·57-1·87) for nicotine dependence, 2·67 (2·38-2·99) for cannabis dependence, and 1·74 (1·62-1·86) for any dependence; and the OR for daily smoking was 2·00 (1·89-2·12). Adjustment for socio-demographic factors made little difference to these associations but a further adjustment for adolescent common mental disorders substantially attenuated most associations, with the exception of daily tobacco smoking (adjusted OR 1·74, 95% CI 1·08-2·81), any illicit drug use (1·72, 1·07-2·79) and weekly cannabis use (3·18, 1·58-6·42). Further adjustment for adolescent risky substance use and antisocial behaviour attenuated the remaining associations, with the exception of weekly cannabis use at age 35 years, which remained independently associated with self-harm during adolescence (2·27, 1·09-4·69). INTERPRETATION: Adolescents who self-harm are more likely to experience a wide range of psychosocial problems later in life. With the notable exception of heavy cannabis use, these problems appear to be largely accounted for by concurrent adolescent mental health disorders and substance use. Complex interventions addressing the domains of mental state, behaviour, and substance use are likely to be most successful in helping this susceptible group adjust to adult life. FUNDING: National Health and Medical Research Council, the Royal Children's Hospital Foundation, and the Murdoch Childrens Research Institute.