University of Calgary

University of Calgary

June 17, 2013 10:00 ET

University of Calgary: Healthy, full-term babies use a different stress hormone than their mother

University researchers investigate the role of corticosterone in signaling fetal distress

CALGARY, ALBERTA--(Marketwired - June 17, 2013) - A University of Calgary researcher has identified how a steroid hormone may indicate infant distress during labour and delivery. The study, published by PLOS ONE this month, suggests that a full-term, healthy baby preferentially secretes a different stress hormone than its mother does. That stress hormone, corticosterone, has not been previously studied in human development.

"Fetal corticosterone, which is related to cortisol, could serve as a biomarker of fetal stress," says study lead author Katherine Wynne-Edwards, PhD, Jack Manns Professor of Comparative Endocrinology. Wynne-Edwards worked with clinical obstetrician/gynecologist Heather Edwards on the study.

"Since cortisol is found in much higher concentrations than corticosterone, it has received greater attention as an indicator of stress in both mothers and newborns."

In this study, investigators compared the concentrations of hormones in the umbilical cord to assess the hormones added to the circulation by the baby. Corticosterone increased during labor and delivery at a significantly greater rate compared to cortisol, although overall cortisol levels were still higher. As fetal stress increased, so did corticosterone concentrations.

Investigators analyzed umbilical cord blood samples from 265 healthy deliveries. Corticosterone concentrations varied according to the delivery- compared to infants delivered by Caesarian section, vaginally delivered infants synthesized greater concentrations of corticosterone. When Caesarian delivery occurred because the baby's head was too large to pass through the birth canal, which was expected to be a stressor on the baby, the highest corticosterone concentrations were seen. Meanwhile, intervention to strengthen maternal contractions did not increase corticosterone concentrations.

"Newborn corticosterone synthesis might be the basis for a signal to the mother that the baby is in distress, and might also indicate that a previously unsuspected developmental transition from preferential corticosterone synthesis to preferential cortisol synthesis occurs in early life," Wynne-Edwards said. "If so, then corticosterone might be an important biomarker of adrenal function in premature infants that is not yet studied or understood."

Wynne-Edwards presented her findings at the Endocrine Society Annual Meeting in San Francisco on June 15, 2013. The study was funded by the Natural Sciences and Engineering Research Council of Canada and an Alberta Advanced Education and Technology grant, through the Faculty of Veterinary Medicine at the University of Calgary.

The research paper can be read online at: http://dx.plos.org/10.1371/journal.pone.0063684.

**Note: Katherine Wynne-Edwards will only be available by phone for interviews.

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The University of Calgary is a leading Canadian university located in the nation's most enterprising city. The university has a clear strategic direction to become one of Canada's top five research universities by 2016, where research and innovative teaching go hand in hand, and where we fully engage the communities we both serve and lead. This strategy is called Eyes High, inspired by the university's Gaelic motto, which translates as 'I will lift up my eyes.'

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Contact Information

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    Gloria Visser-Niven
    Manager, Communications, Faculty of Veterinary Medicine
    403.210-6615 or Cell: 403.542-9444
    gvissern@ucalgary.ca
    ucalgary.ca