Embryo Project Encyclopedia Articles

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.

"Induction and Patterning of the Primitive Streak, an Organizing Center of Gastrulation in the Amniote," (hereafter referred to as "Induction") examines the mechanisms underlying early amniote gastrulation and the formation of the primitive streak and midline axis. The review, authored by Takashi Mikawa and colleagues at Cornell University Medical College, was published in Developmental Dynamics in 2004. The article primarily discusses chick embryos as a model organism for nonrodent amniote gastrulation, although it intermittently touches on nonamniote gastrulation for comparative purposes. "Induction" attempts to explain the initiation of cell differentiation and embryo organization, one of the most intriguing processes of embryology.

Meiosis, the process by which sexually-reproducing organisms generate gametes (sex cells), is an essential precondition for the normal formation of the embryo. As sexually reproducing, diploid, multicellular eukaryotes, humans rely on meiosis to serve a number of important functions, including the promotion of genetic diversity and the creation of proper conditions for reproductive success. However, the primary function of meiosis is the reduction of the ploidy (number of chromosomes) of the gametes from diploid (2n, or two sets of 23 chromosomes) to haploid (1n or one set of 23 chromosomes). While parts of meiosis are similar to mitotic processes, the two systems of cellular division produce distinctly different outcomes. Problems during meiosis can stop embryonic development and sometimes cause spontaneous miscarriages, genetic errors, and birth defects such as Down syndrome.

In 2011, Sarah McMahon and colleagues published “The Impact of Emotional and Physical Violence During Pregnancy on Maternal and Child Health at One Year Post-partum,” hereafter, “The Impact,” in the journal, Child and Youth Services Review. While existing studies had indicated negative chronic effects resulting from intimate partner violence, or IPV, such as miscarriage and premature labor, there was little research specifically analyzing the separate and joint effects of psychological and physical abuse on pregnant women and fetuses. The authors reported that both physical and emotional IPV had negative impacts on the woman and child at one-year after birth, including worse overall health and increased likelihood of depression. In “The Impact,” the researchers analyzed the effects of partner abuse during pregnancy, distinguishing between the effects of emotional abuse and physical abuse on health outcomes for a pregnant woman and her offspring.

In 2001, Kevin M. Godfrey and David J.P. Barker published the article “Fetal Programming and Adult Health” in Public Health Nutrition, where they identified the significance of maternal nutrition during pregnancy to healthy offspring development. The authors describe the effects of maternal nutrition on fetal programming of cardiovascular disease. Fetal programming is when a specific event during pregnancy has effects on the fetus long after birth. The authors argue that fetuses may adapt to varying shifts in their environment in utero, such as slowed fetal growth in response to malnutrition. While those adaptations can be helpful in utero, the authors assert they may persist into adolescence and adulthood, causing conditions such as high blood pressure or diabetes. Godfrey and Barker assert that fetal adaptations to maternal malnutrition may be implicated in the development of cardiovascular disease in adulthood, and called for future research investigating additional fetal programming variables.

The Public Broadcasting Station (PBS) documentary Life's Greatest Miracle (abbreviated Miracle, available at http://www.pbs.org/wgbh/nova/miracle/program.html), is arguably one of the most vivid illustrations of the making of new human life. Presented as part of the PBS television series NOVA, Miracle is a little less than an hour long and was first aired 20 November 2001. The program was written and produced by Julia Cort and features images by renowned Swedish photographer Lennart Nilsson. It comes as a sequel to the award-winning 1983 NOVA production, The Miracle of Life, which exhibits Nilsson's photography as well. The program showcases a combination of graphic animation, endoscopic and microscopic footage, as well as the story of a couple who are expecting a child. It features a number of new technological and scientific developments not present in its prequel, providing additional relevant information. By depicting human development in a clear and fresh manner, Miracle helps shed light on this indispensible aspect of life. Following is a description of the documentary, highlighting the key points of the film and explaining images featured in it.

Sir John Bertrand Gurdon further developed nuclear transplantation, the technique used to clone organisms and to create stem cells, while working in Britain in the second half of the twentieth century. Gurdon's research built on the work of Thomas King and Robert Briggs in the United States, who in 1952 published findings that indicated that scientists could take a nucleus from an early embryonic cell and successfully transfer it into an unfertilized and enucleated egg cell. Briggs and King also concluded that a nucleus taken from an adult cell and similarly inserted into an unfertilized enucleated egg cell could not produce normal development. In 1962, however, Gurdon published results that indicated otherwise. While Briggs and King worked with Rana pipiens frogs, Gurdon used the faster-growing species Xenopus laevis to show that nuclei from specialized cells still held the potential to be any cell despite its specialization. In 2012, the Nobel Prize Committee awarded Gurdon and Shinya Yamanaka its prize in physiology and medicine for for their work on cloning and pluripotent stem cells.

Otto Rank studied how birth impacts individuals’ psychology and creates anxiety throughout their lives in Europe and the US during the nineteenth century. In his book The Trauma of Birth, Rank stated that birth was extremely traumatic and that one spent his or her whole life trying to recover from the experience of being born and harshly separated from the peaceful womb. He argued that the trauma experienced at birth is the source of all human suffering and the key to understanding anxiety later in life. He stated that the experience of birth was one’s earliest experience of anxiety, which served as the blueprint for all other anxiety related experiences in life. Through his work, Rank prompted studies in developmental embryology analyzing early mother-child relationships and problems in early psychological development.

In 2011, fetal researcher Vivette Glover published “Annual Research Review: Prenatal Stress and the Origins of Psychopathology: An Evolutionary Perspective,” hereafter, “Prenatal Stress and the Origins of Psychopathology,” in the Journal of Child Psychology and Psychiatry. In that article, Glover explained how an evolutionary perspective may be useful in understanding the effects of fetal programming. Fetal programming is a hypothesis that attempts to explain how factors during pregnancy can affect fetuses after birth. Researchers associate exposure to prenatal stress, or stress experienced before birth, with an increased likelihood of some mental disorders. Glover states that such outcomes may be traced back to a fetus’s response to stress during pregnancy, and that those outcomes may have been beneficial in the past. By taking an evolutionary approach toward understanding mental disorders, Glover provided insights for studying the lasting effects of maternal stress during pregnancy on children’s mental health.

In 2009, A. John Henderson and colleagues published “Mothers’ Anxiety During Pregnancy Is Associated with Asthma in Their Children,” hereafter, “Mothers’ Anxiety,” in The Journal of Allergy and Clinical Immunology. Previous studies had shown that maternal stress during pregnancy affects children’s health during childhood. The researchers explored the association of asthma in children with maternal anxiety during pregnancy. The cause of asthma is often unknown. Thus, the researchers tested the possibility that maternal anxiety may increase disease risk in the children, particularly the development of asthma. The authors reported a positive association between maternal anxiety during pregnancy and asthma in offspring, indicating the possibility of a causal relationship. The authors’ findings demonstrated the health effects of maternal stress during pregnancy on children’s physiological and immune development.