Primiparas' prenatal depressive symptoms, anxiety, and salivary oxytocin level predict early postnatal maternal-infant bonding: a Japanese longitudinal study.

Purpose: It was reported that maternal-infant bonding failure predicts abusive parenting. Maternal-infant bonding is important to prevent child abuse. This study aimed to investigate the association between prenatal depressive symptoms, anxiety, cortisol, and oxytocin levels, and postnatal maternal-infant bonding.

Methods: The participants completed a self-report prenatal questionnaire that included the Edinburgh Postnatal Depression Scale (EPDS) and State-Trait Anxiety Inventory (STAI) in the second trimester. Blood and saliva were collected in the second trimester. Cortisol levels were measured in plasma, while oxytocin levels were measured in saliva. Postnatal questionnaires, including the Mother-to-Infant Bonding Scale (MIBS), were administered at 2-5 days, 1 month, and 3 months postpartum. Multiple linear regression and generalized estimating equation (GEE) were conducted for analysis.

Results: Sixty-six primiparas participated in the study. Prenatal depressive symptoms (EPDS ≥ 9) and anxiety (STAI-S ≥ 42) were observed in 21.2% and 28.8% of the participants, respectively. The median cortisol and oxytocin levels were 21.0 µg/dL and 30.4 pg/mL, respectively. Multivariate linear regression showed that postnatal social support, prenatal depressive symptoms, anxiety, and salivary oxytocin levels predicted MIBS scores at 2-5 days postpartum. At 1 month postpartum, household income, history of miscarriage, postnatal social support, and prenatal anxiety predicted MIBS scores. At 3 months postpartum, only postnatal social support predicted MIBS scores. The results of GEE showed that prenatal anxiety, oxytocin levels, postpartum period, household income, and postpartum social support were associated with MIBS scores.

Conclusion: Prenatal depressive symptoms, anxiety, and lower salivary oxytocin levels were predicted to worsen maternal-infant bonding at 2-5 days postpartum. Prenatal anxiety was predicted to cause the same 1 month postpartum. Measuring prenatal depressive symptoms, anxiety, and salivary oxytocin levels may render the assessment of the risk of maternal-infant bonding failure during the early postpartum period and intervene during pregnancy possible.