Although much has been written about the impact of pregnancy on expectant parents, less is known about the worries couples experience during pregnancy. Sex differences in worries and the link between self and coparent worries on perinatal well-being and relationship satisfaction in 104 primiparous couples were examined. It was found not only do expectant mothers and fathers worry about different things, but also type of worry is related to different outcomes. Moreover, using structural equation modeling, childbirth worries and worry frequency indirectly predict lower relationship satisfaction through worse well-being. However, coparent's worries did not significantly relate to their partner's perinatal well-being or relationship satisfaction. This study suggests the importance of examining perinatal worries in parents, as well as the dyadic interaction between coparents.