Hormones on infant birth stress

Giving birth activates massive hormonal responses – in mothers and infants – responsible for a range of vital functions, including a newborn’s successful transition from intra-uterine to extra-uterine life.

Because oxytocin is central to maternal functions during labor, it was previously supposed that oxytocin also mediated the birth stress response in infants. Yet thanks to a novel study led by the University of Regensburg, we now know otherwise.

“In contrast to oxytocin, arginine vasopressin is significantly increased after vaginal delivery as compared to deliveries without preceding birth stress, namely elective cesarean section. Thus, oxytocin secretion in infants is not subject to birth stress,” writes Professor Sven Wellmann, MD, MBA, Director Department of Neonatology, University Children’s Hospital Regensburg.

Since both hormones act via shared receptors, it can be concluded that infants experience an oxytocin response as well, which, in contrast to their mothers, is driven by arginine vasopressin.

Further, the research team found that copeptin, a byproduct of arginine vasopressin synthesis, increases more strongly than arginine vasopressin itself and therefore may indicate cumulative stress events over a longer period. Finally, this unique early life hormonal activation could impact life-long neurobehavioral development.

Their full findings have just been published by Frontiers in Neuroscience in this open access article: 'Vasopressin but Not Oxytocin Responds to Birth Stress in Infants'.

Professor Wellmann and his team are also conducting a large, multi-center randomized controlled trial to study the clinical effect of mild uterine contractions prior to elective caesarean section on infant and maternal outcomes after delivery.

FLRF is a proud sponsor of both studies. Interested in staying up to date on this and other news? Subscribe to our newsletter.