A mother’s stress levels around the time of conception may be linked to the way her child responds to life challenges at age 11, according to a new Canadian study published in the Journal of Developmental Origins of Health and Disease.
Researchers from Simon Fraser University (SFU) in British Columbia measured cortisol levels in mothers-to-be, beginning before pregnancy and continuing through the first eight weeks of gestation, and then years later in their children. The aim of the study was to understand the link between a mother’s biological stress around the time of conception and the development of her child’s stress physiology.
Using urine samples to measure reproductive hormones, the researchers were able to pinpoint the day the children were conceived, as well as the moms’ cortisol levels — a biomarker of physiological stress — during the first eight weeks after conception.
Twelve years later, the researchers looked at how the children reacted to the start of a new school year (a well known “natural” stressor) and to a public-speaking challenge (a frequently used “experimental” stressor).
Maternal cortisol following conception was tied to different facets of the children’s cortisol responses to those challenges, and many of these associations differed between boys and girls.
Study lead author Cindy Barha, Ph.D., said that sons of mothers who had higher cortisol in gestational week two had higher cortisol reactions to the experimental public-speaking challenge, but this link was not found in daughters.
In contrast, mothers with higher cortisol in gestational week five had daughters with higher basal (baseline or bottom layer) cortisol before the start of a new school term, but not sons.
However, both sons and daughters had higher cortisol responses to the start of a new school year, as well as to the experimental public speaking challenge, if their mothers had higher cortisol during gestational week five.
The biological mechanisms behind these associations are not yet clear, but are likely to involve genetics and epigenetics as well as environmental and cultural factors shared by moms and their children.
“Stress plays a critical role not only in children’s ability to respond to social and academic challenges, but also in their development and health as adults,” said SFU health sciences professor Dr. Pablo Nepomnaschy, leader of the research team.
The team will continue researching the association between the stress levels of both mother and child from the moment of conception forward. The findings can help develop successful programs and interventions that prepare children to live healthy and fulfilling lives and realize their full potential.
Source: Simon Fraser University