The Aussies are at it again with this systematic review which examines the role of oxytocin in mother-infant relations, attachment, and bonding in humans.

Oxytocin plays an important role in the reproductive life of mammals. The hormone facilitates nest building and pup retrieval in rats, acceptance of offspring in sheep, and the formation of adult pair-bonds in prairie voles.

Research in humans is more limited, but we know that oxytocin stimulates milk ejection during lactation, uterine contraction during birth, and is released during sexual orgasm in both men and women.

This systematic review only found 8 studies, all of which were unique in their methodologies, populations studied, and measures used. Seven studies found significant and strong associations between levels or patterns of oxytocin and aspects of mother-infant relations or attachment.

Here’s what the research team from Melbourne University concluded:

Oxytocin appears to be of crucial importance for understanding mother-infant relationships. The findings of this review suggest that the pioneering, but preliminary, research undertaken to date is promising and that replication with larger samples is needed.

Research that draws on more robust measures of attachment and bonding, as well as improved measures of oxytocin that include both central and peripheral levels, will elucidate the role of oxytocin in human mother-infant relationships.

As the production of oxytocin is by no means restricted to mothers, the extension of the oxytocin studies to fathering, as well as to alloparental caregiving, would be an intriguing next step.

Galbally M, Lewis AJ, Ijzendoorn M, Permezel M. The role of oxytocin in mother-infant relations: a systematic review of human studies. Harv Rev Psychiatry. 2011 Jan-Feb;19(1):1-14. [PubMed abstract]