Fetal Programming: How the Quality of Fetal Life Alters Biology for a Lifetime

After completing this article, readers should be able to: 1. Define the concept of fetal programming. 2. Explain the findings of maternal uterine environment investigations employing embryo transfer techniques. 3. Compare and contrast the effects on fetal growth of removing the fetal pancreas and pituitary gland. 4. Explain the findings of animal studies that suggest critical periods of development in programming. 5. Describe the concept of transgenerational effects. The concept that the conditions that prevail in the womb during prenatal development play as important a role for the function of our bodies and our lifetime health as do our genes has been given increasingly powerful support by recent epidemiologic and animal research data. The scientific underpinning for this concept, often called “fetal programming,” comes from three primary sources: epidemiological studies, clinical practice, and carefully controlled experimental observations in animals. Over the past 30 years, a mounting and overwhelming body of epidemiologic evidence has accumulated from many countries, coming to light slowly through the 1960s, 1970s, and 1980s. Much of the credit for bringing these issues to the forefront of scientific and medical thinking must go to Dr David Barker and his Medical Research Council (MRC) Epidemiology Unit at Southampton University in England. As a result of his pioneering efforts, many researchers in this field call the concept of fetal programming the “Barker hypothesis.” Barker has used human epidemiologic databases to show, for example, that the likelihood of an individual dying as a result of heart disease is increased by more than 50% in men whose birthweights were less than 2.5 kg (5.5 lb) compared with men whose birthweights were 4.3 kg (9.5 lb). The relationship of increased risk is corroborated by the finding that boys who weigh less than 8 kg (18 lb) at 1 year of age have 2.5 times the risk of dying …