The aim of the study was to investigate the association between depressive symptoms in adolescent girls (14 to 18 years) and their pregnancy outcomes in young adulthood (21 to 24 years). The study was a joint collaboration between researchers at the Division of Mental Health at the Norwegian Institute of Public Health, and the Centre for Adolescent Health, Murdoch Children’s Research Institute, and the Royal Children’s Hospital in Melbourne, Australia. The data consisted of 988 young Australian women participating in a longitudinal study (The Victorian Adolescent Health Cohort Study), who were followed from the age of fourteen in 1992 until today. Pregnancy outcomes included becoming pregnant, completing and/or terminating a pregnancy. Depressive symptoms were reported six times during adolescence, while pregnancy outcomes were reported at two stages during young adulthood.
To investigate other possible influences on pregnancy outcomes, women were also asked about their degree of antisocial behavior (such as vandalism, car damage, graffiti, fighting, theft and expulsion from school) and drug use (smoking, cannabis and alcohol) during adolescence. Socio-economic data were also obtained, including parental education and marital status.
Depressed and pregnant?
The researchers found that there was a higher risk of becoming pregnant for the women who reported high depressive symptoms on several occasions during adolescence compared to those who did not report any symptoms. However, this association disappeared when antisocial and drug use behavior, as well as socio-economic variables, were taken into account. Of particular note, adolescent antisocial and drug use behavior were most strongly associated with becoming pregnant and terminating a pregnancy in young adulthood.
“The findings support previous research that suggests a relationship between depression and pregnancy outcomes, but indicate that this relationship either is confounded with or can be explained by antisocial and drug use behavior” says Wendy Nilsen, who is the lead author of the article. This study therefore shows the importance of taking other possible causal factors into account, in addition to the factor of initial interest.
“The findings are useful because they underscore the relationship between antisocial and drug use behavior and pregnancy outcomes in young women. More studies are nevertheless needed before one can say anything clear about the causal relations, but the results suggest that selectively helping young people with a history of antisocial and drug use behavior may improve the future sexual and reproductive health outcomes in this group,” explains Nilsen.
The study is also important in relation to previous research, which has focused mostly on pregnancy outcomes in teenagers, not young adults. Since 1971, the average age of first-time mothers in most Western countries has increased from 25 to 31 years, indicating that the term "early pregnancy" now also can be applied to pregnancy in young adulthood. The findings of this study suggest that some of the same factors (antisocial and drug use behavior) that are related to pregnancy outcomes in teenagers also are related to pregnancy outcomes in young adult women. The shift in the average age of first-time mothers also encourages other types of studies about pregnancy, lifestyle and mental health.
“Further research could look at whether getting pregnant in young adulthood affects some life role transitions, such as establishing a career and/or family,” says Nilsen.
Wendy Nilsen, Craig A. Olsson, Evalill Karevold, Christina O’Loughlin, Maria McKenzie, George C. Patton. (2012) Adolescent Depressive Symptoms and Subsequent Pregnancy, Pregnancy Completion and Pregnancy Termination in Young Adulthood: Findings from the Victorian Adolescent Health Cohort Study. Journal of Pediatric and Adolescent Gynecology, Volume 25, Issue 1, February 2012, Pages 6-11.