Childhood adversity and spontaneous abortion in a North American preconception cohort study.

Childhood adversity has been associated with adverse adult health outcomes. We investigated its association with spontaneous abortion (SAB) risk and the potential buffering effects of social support and integration (SSI). This analysis included 6100 participants from Pregnancy Study Online, a North American preconception cohort study of females attempting spontaneous conception (2013-2024). We assessed childhood adversity via the Adverse Childhood Experiences (ACE) scale and Brief Trauma Questionnaire (BTQ), lifetime SSI via the Berkman-Syme Social Network Index, and pregnancy outcomes via follow-up questionnaires. We used Cox proportional hazards regression models to estimate HRs and 95% CIs, adjusted for potential confounders. Neither the ACE score nor individual ACE domains were appreciably associated with SAB risk. However, participants who reported childhood physical (HR = 1.11 [95% CI, 0.92-1.35]), sexual (HR = 1.12 [95% CI, 0.96-1.30]), or both abuse types (HR = 1.09 [95% CI, 0.90-1.32]) on the BTQ had slightly increased SAB risk compared with those who reported no abuse. Associations were stronger among participants who reported lower childhood SSI (physical and sexual abuse vs no abuse: HR = 1.76 [95% CI, 1.15-2.68]). These findings indicate that BTQ-ascertained physical and sexual abuse may be associated with SAB risk among those with lower childhood SSI.