LAUSR

New mothers often experience significant declines in their sexual and relationship satisfaction compared to pre-pregnancy, yet there has been limited research examining protective factors. Intimacy—defined as the degree of disclosure and perceived partner responsiveness in a relationship—has been identified as contributing to the positive adjustment of individuals coping with novel life stressors, as well as to general sexual and relationship satisfaction. However, it is unknown whether sexual disclosure and/or partner responsiveness are reciprocally related to sexual and relationship satisfaction. This study examined the longitudinal associations between sexual intimacy—that is, intimacy in the context of sex—and sexual and relationship satisfaction in first-time mothers. First-time mothers ( N  = 171) completed online measures assessing disclosure and perceived partner responsiveness specific to their sexual relationship, sexual satisfaction, and relationship satisfaction at 3, 6, and 12 months postpartum. Analyses were conducted with path analysis using a longitudinal panel mediation model. Greater perceived partner responsiveness in relation to sex at a prior wave predicted increases in both sexual and relationship satisfaction at the subsequent wave. Sexual disclosure did not contribute to sexual or relationship satisfaction over time; the results did not support a reciprocal model of sexual disclosure and perceived partner responsiveness, nor indirect effects of these variables on outcomes. Perceived partner responsiveness in relation to sex is positively related, and temporally precedes sexual and relationship satisfaction in first-time mothers.