Embryo Project Encyclopedia

During the mid-twentieth century, Virginia Apgar worked as an obstetrical anesthesiologist and gave drugs to women that reduced their pain during childbirth in the US. In 1953, Apgar created a scoring system, called the Apgar score, that uses five measurements, including heart rate and breathing rate. The Apgar score evaluates newborn infants and determines who needs immediate medical attention. Apgar's work helped decrease infant mortality rates. As of 2020, hospitals around the world use the Apgar score.

Isotretinoin is a molecule and a byproduct (metabolite) of vitamin A, and in greater than normal amounts in pregnant women, it can cause fetal abnormalities including cleft lips, ear and eye defects, and mental retardation. Isotretinoin is commonly called by its trade name Accutane, and it's a chemical compound derived from vitamin A, or retinoic acid. Doctors prescribe isotretinoin to treat severe acne. For pregnant women, too much vitamin A or isotretinoin can also cause greater than normal rates of stillbirths and fetal disintegrations after the ninth week of gestation. Women who use isotretinoin during the first trimester of their pregnancies, even in small amounts, risk defects to their fetuses such as external ear malformations, cleft palates, undersized jaws (micrognathia), a variety of heart defects, buildups of fluids inside the skulls that leads to brain swelling (hydrocephalus), small heads and brains (microcephaly), and mental retardation.

Human pluripotent stem cells are valued for their potential to form numerous specialized cells and for their longevity. In the US, where a portion of the population is opposed to destruction of human embryos to obtain stem cells, what avenues are open to scientists for obtaining pluripotent cells that do not offend the moral sensibilities of a significant number of citizens? It is this question that the official position paper, or white paper, "Alternative Sources of Human Pluripotent Stem Cells," published in May 2005 by the President's Council on Bioethics under the chairmanship of Leon Kass, seeks to answer. Three experts external to the council, Andrew Fire from the Stanford University School of Medicine, Markus Grompe of the Oregon Health and Science University, and Janet Rossant from the Samuel Lunenfeld Research Institute in Toronto, also reviewed the white paper prior to publication.

Matthew Kaufman was a professor of anatomy at the University of Edinburgh, in Edinburgh, UK, who specialized in mouse anatomy, development, and embryology during the late twentieth century. According to the The Herald, he was the first, alongside his colleague Martin Evans, to isolate and culture embryonic stem cells. Researchers initially called those cells Evans-Kaufman cells. In 1992, Kaufman published The Atlas of Mouse Development, a book that included photographs of mice development and mice organs over time. Kaufman also wrote books about UK medical history, phrenology, or the study of craniums as an indicator of character or mental ability, and medical teaching in the eighteenth and nineteenth centuries. Kaufman’s anatomical records and experiments in mouse development contributed to genetic engineering, embryology, and anatomy.

Josef Warkany studied the environmental causes of birth defects in the United States in the twentieth century. Warkany was one of the first researchers to show that factors in the environment could cause birth defects, and he helped to develop guidelines for the field of teratology, the study of birth defects. Prior to Warkany’s work, scientists struggled to explain if or how environmental agents could cause birth defects. Warkany demonstrated that a deficiency or excess of vitamin A in maternal nutrition could cause birth defects. He also established that mercury in teething powders increased infant mortality rates. Warkany showed how substances outside the human body could adversely affect conception, growth, and development of the human fetus in utero.

In its 1993 decision Daubert v. Merrell Dow Pharmaceuticals, Inc., the US Supreme Court established the Daubert Standard for evaluating the admissibility of scientific knowledge as evidence in US federal courts. When it began in trial court, the case addressed whether or not Bendectin, an anti-nausea medication taken during pregnancy, caused birth defects. However, after the trial court dismissed the case for lack of admissible evidence, Daubert v. Merrell Dow Pharmaceuticals, Inc. advanced through appeals courts to the US Supreme Court, where the Justices defined the criteria by which scientific knowledge, which for them included a least theories based on evidence, expert testimony from scientists, and scientific techniques, could be introduced and used in court cases as evidence. The Daubert Standard states that the judge of a case is responsible for determining what claims are admissible as scientific knowledge and as evidence in the case. The admissibility should be determined by the falsifiability of the claims, by whether or not they had passed peer reviewed, by the general scientific acceptance of the claims, and for techniques, by their error rates of the techniques. Daubert v. Merrell Dow Pharmaceuticals, Inc. set a landmark precedent in the US judicial system and influenced most subsequent legal cases that appealed to science to establish facts in trials.

In March 1996, the National Academy of Sciences of the United States released 'Veterans and Agent Orange Update 1996: Summary and Research Highlights,' which summarized research on the health effects of Agent Orange and other herbicides used in the Vietnam War. In their 1996 report, the National Academy connects Agent Orange exposure with two health conditions: spina bifida, a birth defect that occurs when the spinal cord develops improperly, and peripheral neuropathy, a nervous system condition in which the peripheral nerves are damaged. Spina bifida was the first birth defect to linked to Agent Orange exposure. The resulting disability compensation for affected children, as a result of the conclusions in the 1996 report, marked the first time that the US Veterans Administration addressed the health outcomes of veterans' families, and not exclusively veterans themselves.

In the twentieth and early twenty-first centuries, Gail Roberta Martin specialized in biochemistry and embryology, more specifically cellular communication and the development of organs. In 1981, she named any cell taken from inside a human embryo at the blastocyst stage an “embryonic stem cell”. During development, an embryo goes through the blastocyst stage just before it implants in the uterus. Embryonic stem cells are useful for experiments because they are self-renewing and able to develop into almost any cell type in the body. Martin later identified a key chemical component in limb development and continues to study embryogenesis, or the growth of embryos over time. Martin’s work on embryonic stem cells has allowed scientists to further research and treat human diseases, and her study of how organs form has helped scientists learn about the healthy growth of embryos.

Sprayed extensively by the US military in Vietnam, Agent Orange contained a dioxin contaminant later found to be toxic to humans. Despite reports by Vietnamese citizens and Vietnam War veterans of increased rates of stillbirths and birth defects in their children, studies in the 1980s showed conflicting evidence for an association between the two. In 1996, the US National Academy of Sciences reported that there was evidence that suggested dioxin and Agent Orange exposure caused spina bifida, a birth defect in which the spinal cord develops improperly. The US Department of Veterans Affairs' subsequent provision of disability compensation for spina bifida-affected children marked the US government's first official acknowledgement of a link between Agent Orange and birth defects. By 2016, spina bifida and related neural tube defects were the only birth defects associated with Agent Orange.