Adverse childhood experiences are associated with increased risk of miscarriage in a national population-based cohort study in England

STUDY QUESTION Is there an association between adverse childhood experiences (ACE) and the risk of miscarriage in the general population? SUMMARY ANSWER Specific ACE as well as the summary ACE score were associated with an increased risk of single and recurrent miscarriages. WHAT IS KNOWN ALREADY There is scarce evidence on the association between ACE and miscarriage risk. STUDY DESIGN, SIZE, DURATION We conducted a retrospective national cohort study. The sample consisted of 2795 women aged 55-89 years from the English Longitudinal Study of Ageing (ELSA). PARTICIPANTS/MATERIALS, SETTING, METHODS Our study was population-based and included women who participated in the ELSA Life History Interview in 2007. We estimated multinomial logistic regression models of the associations of the summary ACE score and eight individual ACE variables (pertaining to physical and sexual abuse, family dysfunction and experiences of living in residential care or with foster parents) with self-reported miscarriage (0, 1, >= 2 miscarriages). MAIN RESULTS AND THE ROLE OF CHANCE Five hundred and fifty-three women (19.8% of our sample) had experienced at least one miscarriage in their lifetime. Compared with women with no ACE, women with >= 3 ACE were two times more likely to experience a single miscarriage in their lifetime (relative risk ratio 2.00, 95% CI 1.25-3.22) and more than three times more likely to experience recurrent miscarriages (>= 2 miscarriages) (relative risk ratio 3.10, 95% CI 1.63, 5.89) after adjustment for birth cohort, age at menarche and childhood socioeconomic position. Childhood experiences of physical and sexual abuse were individually associated with increased risk of miscarriage. LIMITATIONS, REASONS FOR CAUTION Given the magnitude of the observed associations, their biological plausibility, temporal order and consistency with evidence suggesting a positive association between ACE and adverse reproductive outcomes, it is unlikely that our findings are spurious. Nevertheless, the observed associations should not be interpreted as causal as our study was observational and potentially susceptible to bias arising from unaccounted confounders. Non-response and ensuing selection bias may have also biased our findings. Retrospectively measured ACE are known to be susceptible to underreporting. Our study may have misclassified cases of ACE and possibly underestimated the magnitude of the association between ACE and the risk of miscarriage. WIDER IMPLICATIONS OF THE FINDINGS Our study highlights experiences of psychosocial adversity in childhood as a potential risk factor for single and recurrent miscarriages. Our findings contribute to a better understanding of the role of childhood trauma in miscarriage and add an important life course dimension to the study of miscarriage.