Abstract
Oxytocin is a key hormone in the transition to motherhood. The maternal endogenous oxytocin system facilitates many physiological and biological adaptations, including breastfeeding, maternal wellbeing, and brain plasticity. Additionally, maternal endogenous oxytocin works as a finetuned orchestrator prior to, during, and after the birth of a child to support birth progression and mother-infant bonding. Exogenous oxytocin may be administered to induce or augment labour when this is not progressing naturally and is a common obstetric intervention worldwide. However, the lasting impact of these widely varying levels of systemic exogenous oxytocin on mother-infant bonding is currently unknown. This study aimed to investigate the association between exogenous oxytocin administered to induce or augment labour and quality of observed mother-infant bonding. Thirty-eight mother and infant dyads participated (mothers aged 24-48 years; infants aged 2-5 months). Mother-infant bonding quality was assessed via the Recorded Interaction Task and hospital birth records were consulted to obtain exogenous oxytocin administration data. Demographic information and possible confounding factors were collected from dyads, and salivary oxytocin concentration was measured for both mother and infant. Mother's perception of infant sleep difficulty was identified as a confounding factor for quality of mother-infant bonding. After controlling for the confounding factor, receiving exogenous oxytocin to induce or augment labour, as opposed to not, was found to be significantly positively associated with higher quality of observed mother-infant bonding (p = 0.029). These novel findings highlight the need for further exploration, both of the impact of the treatment and of the mechanisms of action of intrapartum exogenous oxytocin on the endogenous oxytocin system. It is argued that particular focus be given to investigate action on the central oxytocin receptors, and if this may play a role in subsequent mother-infant bonding outcomes. It is vital to understand the full breadth and the clinical implications of this commonplace procedure.