Total Adverse Childhood Experiences and Preterm Birth: A Systematic Review.

Introduction: Total adverse childhood experiences (ACEs) are gaining prominence as a risk factor for preterm birth (PTB). The emerging literature examining this relationship reports inconsistent findings. The purpose of this systematic review was to summarize the available evidence exploring whether total ACEs predict PTB. Methods: A total of 386 studies were returned from searches on PubMed, PsycINFO, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). Nine studies were selected for final analysis and synthesis based on reporting of total ACEs and preterm birth gestational weeks or standard definition of birth before 37 weeks' gestational age. A systematic review rather than meta-analysis was selected to present the findings given the clinical and methodological (e.g., sample studied, measurement tools) heterogeneity of the retrieved studies and pregnancy outcomes measured. Results: The nine studies report on birth outcomes for 6,087 women from a range of sociodemographic and ethnic backgrounds. Despite a wide range of study designs, measurement tools, and timings of ACEs exposure across studies, seven of the nine included studies showed significant relationships between ACEs and PTB. Conclusion: Systematic review of the literature suggests that total ACEs are associated with PTB and provides an overview on the known associations. However, to date only nine studies have assessed this link, and more studies are needed, to explore the associations between ACEs and PTB using appropriate and valid instruments and doing so among more diverse populations. Future research should also explore possible biological mechanisms (allostatic load), and moderating and mediating variables. [ABSTRACT FROM AUTHOR]