Traumatic events: exploring associations with maternal depression, infant bonding, and oxytocin in Latina mothers

Childhood and adulthood traumatic experiences negatively impact maternal-infant bonding and increase risk of postpartum depression (PPD). Lower oxytocin levels have also been associated with PPD and compromised mother-infant bonding. Despite advances in these areas of investigation, much of the research has not included Latinas, who are important because they have high rates of fertility, traumatic events, and PPD.

To address gaps identified in the literature, we explored associations between traumatic life events, PPD, and bonding subscale scores (e.g., Impaired Bonding, Rejection and Anger, Anxiety about Care) in a sample of 28 Latinas. We also examined associations between these factors and oxytocin (OT). Wilcoxon signed-rank tests were employed to examine differences in subscale scores over time. Kruskal-Wallis one-way analysis of variance was used to examine differences in bonding subscale scores and OT by maternal depression status and traumatic events. We also explored interaction effects of traumatic events and OT AUC on bonding subscale scores.

Women with PPD at 8 weeks had significantly higher Rejection and Anger subscale scores (p = 0.054) than non-PPD women, where higher scores represent more compromised bonding. Significant differences in Rejection and Anger (p = 0.042) and Anxiety about Care (p = 0.005) by adulthood traumatic histories were observed at 8 weeks postpartum. There was also a significant difference in Anxiety about Care scores at 4 weeks postpartum (p = 0.024) and Impaired Bonding at 8 weeks postpartum (p = 0.041) by trauma events involving an infant. There was a significant interaction between OT and childhood sexual abuse on Impaired Bonding (p = 0.038).

We observed differential responses in bonding subscale scores by traumatic histories. Women who experienced a trauma involving an infant had higher compromised bonding scores, whereas those with adulthood traumatic histories, such as intimate partner violence, had lower scores. We also found an interaction between childhood trauma and oxytocin levels on bonding scores, suggesting a physiological response to early abuse that can have implications on mothers' bonding perceptions. These preliminary results suggest the need for additional research on the long-term emotional and physiological effects of traumatic events occurring prior to parturition.