Background. A broad body of studies have shown that emotional well-being during pregnancy influences birth outcome and postpartum mood state, but few longitudinal studies have examined the extent of changes of emotional well-being during late pregnancy. Furthermore, up to now it has remained unclear which factors are predictive for emotional well-being during pregnancy. This prospective longitudinal study has two main aims. First of all, possibly occurring changes of birth anxiety, self-efficacy for labor and delivery, and psychosocial adaptation to pregnancy in primiparous healthy women during the final trimenon will be described. Second, predictors of these assessed constructs during the final trimenon as well as the extent of these constructs as predictors for the psychological status postpartum will be shown. Methods. A prospective longitudinal study was conducted with 61 pregnant women recruited from childbirth classes. Results. The results showed significant changes in emotional well-being – measured by birth anxiety, self-efficacy for labor and delivery, and psychosocial adaptation to pregnancy – during the final trimenon: the women were more confident in their ability to cope with labor and delivery. Birth anxiety did not change significantly during the final trimenon. Regression analyses revealed different psychosocial predictor variables for emotional well-being during late pregnancy. The predictive factor for an unfavorable psychological status postpartum was birth anxiety. Conclusions. The results of this study suggest that the importance of discovering psychosocial problems of pregnant woman early in pregnancy could be imperative in preventing psychosocial problems later in pregnancy as well as postpartum.