BackgroundAlthough several studies have found significant relationships between autistic traits and depression/anxiety, the relationships between autistic traits and postpartum depression/anxiety remain unclear. Moreover, few studies have examined the relationships between autistic traits and mother–infant bonding while considering depression or anxiety.MethodsThis study used a cross-sectional data analysis design. Participants were 2692 women who completed the Autism-Spectrum Quotient (AQ), Hospital Anxiety and Depression Scale (HADS), and Mother-to-Infant Bonding Scale (MIBS) at 1 month postpartum. We performed path analysis that included parity, the five AQ subscales (social skills, attention switching, attention to detail, communication, and imagination), both HADS subscales (anxiety and depression), and the two MIBS subscales (lack of affection and anger and rejection).ResultsOur path analysis revealed that higher scores for social skills, attention switching, communication, and imagination were associated with higher scores for depression. Higher scores for social skills, attention switching, attention to detail, and communication were associated with higher scores for anxiety. Moreover, difficulties in social skills and imagination were associated with failure of maternal–infant bonding. However, more attention to detail was associated with better maternal–infant bonding.ConclusionsThis study suggests that maternal autistic traits are related to anxiety and depression to a certain degree, but only slightly related to maternal–infant bonding at 1 month postpartum. To improve autistic women’s quality of life and that of their newborns, perinatal mental health issues such as anxiety, depression, and maternal–fetal bonding difficulties should be appropriately addressed.