Researchers at the University of Trier, Germany, say that stressful or traumatic events experienced during pregnancy can have long-lasting effects on the fetus, and these effects may not become apparent until many years later. They cite fibromyalgia as one example, claiming that girls born of stressful pregnancies may be at a greater risk for developing the painful muscle condition as adults. Little is known about the causes of fibromyalgia, a condition affecting mostly women and characterized by extreme fatigue and widespread muscle pain. In the new study, led by Dirk Hellhammer, the researchers found that "prenatal programming" likely plays a role in the later development of fibromyalgia. Hellhammer says that stress experienced during pregnancy can affect the development of the fetus's adrenal gland, permanently limiting its capacity for producing adequate amounts of the hormone cortisol.
Hellhammer's findings, presented at the International Congress of Neuroendocrinology, were based on a group of women diagnosed with fibromyalgia who reported their mothers had experienced profound stress during pregnancy, such as the loss of a partner, physical or emotional trauma or lack of social support. Additionally, the women born from such pregnancies had "blunted" cortisol response in a standardized measure of psychological stress. Furthermore, the low cortisol levels were only observed in the patients with a history of prenatal stress.
Hellhammer believes his study provides strong evidence that girls may be at added risk for developing fibromyalgia if, while in the womb, they were exposed to higher than normal levels of cortisol produced by their mothers in response to stress.
The same conference also heard a worrying report from scientists at the University of Toronto (UT) about how steroid drugs used during pregnancy can affect future generations. UT's Stephen G. Matthews explained how glucocorticoid (a synthetic hormone commonly given to pregnant women at risk for delivering early) not only causes permanent changes to the newborn's neuroendocrine system, but may have even greater effects on those born in the next generation.
Around 7 percent of pregnant women are treated with glucocorticoid to help hasten lung development when pre-term birth seems likely. Both animal and human clinical studies have shown the treatment could have long-term effects on neuroendocrine function and behavior, said Matthews. Moreover, exposure in the womb to these synthetic hormones, which also have potent anti-inflammatory and immunosuppressive properties, can have life-long consequences.
According to Matthews' research, exposure affects the hypothalamic-pituitary-adrenal axis (HPA), which controls how the body responds to stress and is involved in regulation of energy balance and the immune system as well. Now, in more recent studies, his group is finding such effects extend to second generation offspring, in whom changes to HPA function and behavior are even greater than in those directly exposed.
Source: University of Pittsburgh Medical Center
