This Wednesday, Richard Kinkead, professor of Pediatrics at Laval University, gave a lecture on recent research into gestational stress (GS) and its consequences in respiratory control development in the fetus.
According to Kinkead, when we are stressed we release a hormone called cortisol; this is called the neuroendocrine response. Normally, this response prepares us for danger, a “flight-or-fight” response.
However, Kinkead explained that when cortisol levels get high enough they can be harmful. For example, too much cortisol in the mother during pregnancy is associated with preterm birth. This in turn is correlated with several major causes of morbidity in newborns, including respiratory instability, apnea, and bradycardia (a slow heart).
Since the fetus is rapidly growing, it is at high vulnerability to its environment. This environment is composed of many factors, including hormones, which is why GS can be so harmful.
Kinkead studied this GS in rat models. Pregnant mothers were stressed by periodically exposing them to fox (a predator) odor. The newborn pups were then tested. From this, Kinkead found that GS decreases birth weight and reduces the arousal response to hypoxia (lack of enough oxygen), suggesting that GS may be a risk factor for sudden infant death syndrome (SIDS).
These results prompted further experimentation into 5-HT neurons (brain cells), which are important in modulating respiratory activity and are highly sensitive to stress. The results showed that GS significantly affects the development of these 5-HT neurons, perhaps from a reduction in serotonin.
Overall this research raised many important questions about gestational stress and how to prevent or treat the disorders that arise from it. In the future, Kinkead will be looking into whether the effects of GS persist into adulthood, demonstrating the true significance that stress can have on all our lives.