The prevailing dominant discourse about motherhood in western societies reflects a set of interconnected beliefs referred to as intensive mothering ideology. Little is known about how intensive mothering ideology changes after childbirth, and the associations between intensive mothering ideology and maternal mental health. The current study aims to explore how intensive mothering ideology may evolve after childbirth in both primiparous and multiparous women, and whether any observed changes in this ideology impact maternal mental health. French women (n = 144) completed a set of study measures during late pregnancy and then again at two months and four months postpartum, which assessed intensive mothering ideology, postpartum depression, and maternal burnout symptoms. As expected, the results indicated that intensive mothering ideology increases after childbirth. However, changes in ideology were not stronger in primiparous women compared to multiparous women. Of note, multiparous women reported stronger challenge and sacrifice beliefs. Finally, linear mixed models showed that changes in intensive mothering ideology were associated with maternal mental health in contradictory ways, while controlling for parity and unemployment. Mainly, growth in sacrificial beliefs seems to be detrimental to maternal mental health. These findings have implications for the well-being of mothers after childbirth and call for challenging the self-sacrifice beliefs that underpin intensive mothering ideology in order to promote self-care.< Réduire