Dual Mediation of Body Image Effects on Antenatal Depression in Late Pregnancy: Negative Rumination as the Dominant Pathway

Background Antenatal depression represents a significant public health concern, with body image disturbances identified as a prominent risk factor during pregnancy. However, the specific cognitive mechanisms, particularly the distinct roles of positive and negative rumination, underlying the relationship between body image and antenatal depression remain inadequately explored. This study aimed to investigate the associations between maternal body image, rumination subtypes, and antenatal depression, and to examine the parallel mediating roles of positive and negative rumination in late pregnancy. Methods A cross-sectional study recruited 288 women (gestational age ≥ 28 weeks) from a tertiary hospital in Guangzhou, China. Participants completed validated scales: the Body Image in Pregnancy Scale (BIPS), Positive and Negative Rumination Scale (PANRS), and Edinburgh Postnatal Depression Scale (EPDS). Pearson correlations assessed bivariate associations. Bootstrapped parallel mediation analysis (5,000 resamples) evaluated direct and indirect effects using structural equation modeling. Results Body image correlated positively with antenatal depression severity ( r  = 0.37, P  < 0.001) and negative rumination ( r  = 0.36, P  < 0.001), but negatively with positive rumination ( r  = − 0.21, P  < 0.001). Body image exerted a significant total effect on antenatal depression ( β  = 0.12, 95% CI [0.09, 0.16]). Rumination subtypes jointly mediated 53.63% of this effect. Negative rumination demonstrated dominant mediation (indirect β  = 0.05, 95% CI [0.03, 0.07]; proportion: 41.05%), significantly exceeding positive rumination (indirect β  = 0.02, 95% CI [0.004, 0.03]; proportion: 12.66%; ratio = 3.24:1). The direct effect remained significant ( β  = 0.06, 95% CI [0.02, 0.09]). Conclusion Negative body image elevates antenatal depression risk primarily by amplifying negative rumination while concurrently suppressing protective positive rumination. These findings validate objectification theory in pregnancy and underscore rumination’s dual-dimensional mediation. Antenatal interventions should integrate cognitive restructuring to mitigate maladaptive body-related cognitions and enhance positive reappraisal of gestational changes.