Years of education mediate the association between adverse childhood experiences and unintended pregnancy: A population-based study in Japan.

BACKGROUND

Adverse childhood experiences (ACEs) have been associated with unintended pregnancies, including mistimed pregnancies (MP) and unwanted pregnancies (UWP). However, it remains unknown which cluster of ACEs (i.e., child maltreatment/household dysfunction and deprivation/threat) are associated with MP/UWP and whether years of education mediate these associations.

OBJECTIVE

To investigate the association of the clusters of ACEs with MP and UWP, while also examining the mediating effect of education years.

PARTICIPANTS AND SETTING

A retrospective cohort study among 7652 postpartum women in Chiba, Japan.

METHODS

MP/UWP was defined by emotional responses to confirming pregnancy. Multinomial logistic regression analyses with multiple imputed datasets estimated the relative risk ratio (RRR) of MP/UWP by cumulative scores and each cluster of ACEs. Causal mediation analysis assessed the indirect effects of years of education.

RESULTS

Women with 4 or more ACEs were at a 2.4 times higher risk of MP (95 % confidence interval (CI): 1.6-3.8) and a 5.0 times higher risk of UWP (95 % CI: 3.1-8.2). Among ACE clusters, having 3 or more household dysfunction showed the strongest association with MP (RRR: 1.91, 95 % CI: 1.23-2.95), and having 3 or more deprivation showed the strongest association with UWP (RRR: 3.69, 95 % CI: 2.00-6.83). Education years mediated 16 % and 11 % of the association between total ACEs and MP/UWP, respectively, with a similar trend observed in each cluster.

CONCLUSIONS

Not only ACEs score but also each cluster of ACEs was associated with MP and UWP. The mediating effects of years of education were modest.