The first year postpartum is often a challenging time for romantic partners. During this time, couples tend to experience less relationship intimacy and sexual satisfaction, which may be further exacerbated by individual stressors and vulnerabilities. Little is known about whether a maternal history of adverse life events and mental health prior to the infant’s birth negatively interfere with postpartum relationship and sexual well-being. Accordingly, the current study examined whether maternal trauma history, prenatal posttraumatic stress, and prenatal depressed mood were risk factors for poor postpartum couple adjustment. It also investigated whether perceiving a partner as motivated to meet one’s interest and disinterest in sexual activity, referred to as sexual communal strength for having sex (SCS for having sex) and sexual communal strength not having sex (SCS for not having sex), were buffers to relationship deterioration among mothers with this history of adversity. One hundred and sixty women (N = 160) who had completed an earlier study during pregnancy participated in a subsequent online survey between six and twelve months postpartum. Using path analysis to investigate the prospective relationships between maternal trauma history, prenatal mental health difficulties, and postpartum relationship and sexual well-being, trauma history was found to significantly predict sexual satisfaction and desire. Specifically, childhood maltreatment predicted poorer sexual well-being following childbirth, whereas adult sexual victimization predicted improved sexual well-being. No other pathways in the model were significant. Additionally, contrary to predictions, sexual communal strength did not moderate associations between maternal prenatal adversity and postpartum relationship outcomes in the primary analyses. However, follow-up analyses including only mothers who reported some symptoms of PTSD revealed that SCS for having sex moderated the association between these symptoms and relationship satisfaction. Results from this research highlight that childhood maltreatment likely has enduring detrimental implications for women’s sexual well-being as they transition- either again or for the first time - to motherhood. Further implications and directions for future research in this area are discussed. / Graduate