The Biology of Belief - Bruce H. Lipton [77]
But the developing child receives far more than nutrients from the mother’s blood. Along with nutrients, the fetus absorbs excess glucose if the mother is diabetic and excess cortisol and other fight or flight hormones if the mother is chronically stressed. Research now offers insights into how the system works. If a mother is under stress, she activates her HPA axis, which provides fight or flight responses in a threatening environment.
Stress hormones prepare the body to engage in a protection response. Once these maternal signals enter the fetal blood stream, they affect the same target tissues and organs in the fetus as they did in the mother. In stressful environments, fetal blood preferentially flows to the muscles and hindbrain, providing nutritional requirements needed by the arms and legs and by the region of the brain responsible for life-saving reflex behavior. In supporting the function of the protection-related systems, blood flow is shunted from the viscera organs and stress hormones suppress forebrain function. The development of fetal tissue and organs is proportional to both the amount of blood they receive and the function they provide. When passing through the placenta, the hormones of a mother experiencing chronic stress will profoundly alter the distribution of blood flow in her fetus and change the character of her developing child’s physiology. (Lesage, et al, 2004; Christensen 2000; Arnsten 1998; Leutwyler 1998; Sapolsky 1997; Sandman, et al, 1994)
At the University of Melbourne, E. Marilyn Wintour’s research on pregnant sheep, who are physiologically quite similar to humans, has found that prenatal exposure to cortisol eventually leads to high blood pressure (Dodic, et al, 2002). Fetal cortisol levels play a very important regulatory role in the development of the kidney’s filtering units, the nephrons. A nephron’s cells are intimately involved with regulating the body’s salt balance and consequently are important in controlling blood pressure. Excess cortisol absorbed from a stressed mother modifies fetal nephron formation. An additional effect of excess cortisol is that it simultaneously switches the mother’s and the fetus’s system from a growth state to a protection posture. As a result, the growth-inhibiting effect of excess cortisol in the womb causes the babies to be born smaller.
Suboptimal conditions in the womb that lead to low birth-weight babies have been linked to a number of adult ailments that Nathanielsz outlines in his book Life In The Womb, (Nathanielsz 1999) including diabetes, heart disease and obesity. For example, Dr. David Barker (ibid.) of England’s University of Southampton has found that a male who weighs fewer than 5.5 pounds at birth has a 50 percent greater chance of dying of heart disease than one with a higher birth weight. Harvard researchers have found that women who weigh fewer than 5.5 pounds at birth have a 23 percent higher risk of cardiovascular disease than women born heavier. And David Leon (ibid.) of the London School of Hygiene and Tropical Medicine has found that diabetes is three times more common in 60-year-old men who were small and thin at birth.
The new focus on the influences of the prenatal environment extends to the study of IQ, which genetic determinists and racists once linked simply to genes. But in 1997, Bernie Devlin, a professor of psychiatry at the University of Pittsburgh School of Medicine, carefully analyzed 212 earlier studies that compared the IQs