Few studies have shown the psychological impact of the COVID-19 pandemic on new mothers' health, but the long-term consequences of the crisis are yet unknown. This study aimed at evaluating the changes experienced in perinatal mental health 6 months after the start of the COVID-19 pandemic in Spain. Women (n = 176, average age = 33.80) were recruited during the pandemic. Participants completed the Edinburgh Postnatal Depression Scale, the Satisfaction With Life Scale and Positive, and the Negative Affect Schedule. Results showed a decrease in depressive symptoms, t(174) = 2.58, p = .01, d = 0.02, whereas anxiety symptoms remained high, t(174) = 1.31, p = .19. In terms of psychological well-being, the results showed a decrease in life satisfaction, t(175) = 2.58, p = .011, d = 0.16, and negative affect, t(175) = 3.15, p = .002, d = 0.26, and an increase in positive affect, t(175) = -4.45, p < .001, d = 0.35. This study is expected to shed light on the design of future interventions aimed at the prevention of symptoms and to enhance life satisfaction during the perinatal stage.