NEUROENDOCRINE BALANCE AND ITS RELATIONSHIP WITH MOTHER-CHILD INTERACTION DURING THE POSTPARTUM PERIOD

During pregnancy and postpartum, physiological changes affect pregnant women’s stress management and caregiving behavior. Oxytocin and cortisol, biomarkers usually considered separately, have been suggested to influence resilience to stress and mother-child interactions greatly. Despite a growing body of research on the neurobiological underpinnings of the caregiving system, few studies have focused on the reciprocal relationship between oxytocin and cortisol. Previous studies have shown that postpartum stress-related outcomes might rely on balancing oxytocin and cortisol stress responses (e.g. Li, Hassett, Seng, 2019). Herein, we evaluated (a) changes in salivary cortisol, oxytocin levels, and their balance in 29 primiparous women (Mn age=33.36; Sd =4.29) in the prepartum and postpartum period and (b) the relationship of the balance between postpartum’ oxytocin and cortisol with the quality of mother-child interactions during Still Face Paradigm (SFP) at three months postpartum. Results of the Wilcoxon non-parametric test showed a significant increase in oxytocin levels (Z=-4.42; p<.001), a significant decrease in cortisol levels (Z=-4.66; p<.001), and an increase in the ratio between oxytocin and cortisol (Z=-4.68; p<.001) after childbirth. The Spearman correlations highlighted a relationship among postpartum ratio between oxytocin and cortisol with more functional interactions between mothers and child during SFP (Rho=-.413; p<.05). The findings confirm a change in the production of oxytocin and cortisol, alongside alterations in their balance following birth. Moreover, enhanced mutual regulation between these two hormones results in fewer indicators of negative emotions and hostility in the mother’s engagement with the child. Our exploratory study highlights the significance of investigating the mutual regulation of oxytocin and cortisol as a sign of resilience to stress, particularly in the mother-infant interactions during the postpartum period.