During the twentieth century, Thomas Raphael Verny studied the way that environment affects a developing fetus’s character and psychological development. Verny studied the concept of memory before birth and covered both the prenatal and perinatal periods, meaning the time the fetus is in the womb and the weeks immediately before or after birth, respectively. During those times, Verny claimed that patterns of maternal attitudes and experiences, such as affection and stress-related emotions, impact the development of the child. Published in 1981, Verny’s book The Secret Life of the Unborn Child presented novel ideas about how pregnant women’s emotional health impacts the psychological, emotional, and physical development of their fetuses, sparking discussion about the importance of maternal emotional health during prenatal development.

In 2000, Catherine Monk, William Fifer, Michael Myers, Richard Sloan, Leslie Trien, and Alicia Hurtado published “Maternal stress responses and anxiety during pregnancy: Effects on fetal heart rate,” in which the authors conducted a study on how pregnant women’s stress and anxiety affects the health of their fetuses. Previous studies had shown that stress and anxiety during pregnancy could cause fetal abnormalities. In their article, Monk and colleagues reported that the fetuses of anxious pregnant women were more likely to have elevated heart rates and increased stress when exposed to stressors than fetuses of non-anxious women. The authors’ findings indicated that fetuses of anxious women display more biological markers of stress than fetuses of non-anxious women.

In 2004, Amanda J. Drake and Brian R. Walker published “The Intergenerational Effects of Fetal Programming: Non-genomic Mechanisms for the Inheritance of Low Birth Weight and Cardiovascular Risk,” hereafter, “The Intergenerational Effects,” in the Journal of Endocrinology. In their article, the authors assert that cardiovascular disease may develop via fetal programming, which is when a certain event occurring during a critical point of pregnancy affects the fetus long after birth. Drake and Walker were among the first to show that the programming effects of cardiovascular disease could be sustained across generations through non-genetic means. In “The Intergenerational Effects,” the authors identify how non-genetic mechanisms may perpetuate fetal programming influences over generations, highlighting the importance for further research on fetal programming.

In 2001, researchers Leonie Welberg and Jonathan Seckl published the literature review “Prenatal Stress, Glucocorticoids, and the Programming of the Brain,” in which they report on the effects of prenatal stress on the development of the fetal brain. The fetus experiences prenatal stress while in the womb, or in utero. In discussing the effects of prenatal stress, the authors describe prenatal programming, which is when early environmental experiences permanently alter biological structure and function throughout life. Throughout “Prenatal Stress, Glucocorticoids and the Programming of the Brain,” Welberg and Seckl provide a number of potential biological explanations, derived from both animal and human studies, to explain the underlying mechanisms involved in programming, which helped establish how in utero stress can affect fetal brain development.

Fetal programming, or prenatal programming, is a concept that suggests certain events occurring during critical points of pregnancy may cause permanent effects on the fetus and the infant long after birth. The concept of fetal programming stemmed from the fetal origins hypothesis, also known as Barker’s hypothesis, that David Barker proposed in 1995 at the University of Southampton in Southampton, England. The fetal origins hypothesis states that undernutrition in the womb during middle to late pregnancy causes improper fetal growth, which in turn, causes a predisposition to certain diseases in adulthood. In addition to nutritional impacts, researchers have studied the fetal programming effects of many factors, such as maternal anxiety or violence during pregnancy. Researchers proposing the concept of fetal programming established a new area of research into the developmental causes of disease, pointing towards the in utero environment and its critical role in healthy human development.