Congenital rubella syndrome (CRS) can occur in children whose mothers contracted the rubella virus, sometimes called German measles, during pregnancy. Depending on the gestational period when the mother contracts rubella, an infant born with CRS may be unaffected by the virus or it may have severe developmental defects. The most severe effects of the virus on fetal development occur when the mother contracts rubella between conception and the first trimester. Defects from maternal rubella in the first trimester are included in the term congenital rubella syndrome, but physicians and researchers specifically refer to those defects as rubella embryopathy. Developmental defects are less severe if the mother contracts rubella in the second trimester, and they are generally negligible if the infection occurs in the third trimester. Prenatal rubella infection can cause birth defects which include deafness, compromised vision, abnormal heart development, and damage to the central nervous system which can lead to compromised cognition and learning disabilities.

In the early twentieth century, scientists and agriculturalists collected plants in greenhouses, botanical gardens, and fields. Seed collection efforts in the twentieth century coincided with the professionalization of plant breeding. When scientists became concerned over the loss of plant genetic diversity due to the expansion of a few agricultural crops around mid-century, countries and organizations created seed banks for long-term seed storage. Around 1979, environmental groups began to object to what they perceived as limited access to seed banks, and they questioned the ownership of the intellectual property of living organisms. Controversy also ensued over the uneven flow of genetic resources because many of the seed banks were located in the global North, yet plants were collected largely from countries in the global South. The environmental groups' campaigns, which some called the seed wars, and the movement for biodiversity conservation intersected in ways that shaped debates about plant genetic material and seed banking. Several significant shifts in governance occurred in 1994 that led to the creation of the International Plant Genetic Resources Institute in Italy, and to changes in the governance of several international seed banks.

Farmers have long relied on genetic diversity to breed new crops, but in the early 1900s scientists began to study the importance of plant genetic diversity for agriculture. Scientists realized that seed crops could be systematically bred with their wild relatives to incorporate specific genetic traits or to produce hybrids for more productive crop yields. The spread of hybrids led to less genetically diversity than normal plant populations, however, and by 1967, plant scientists led an international movement for conservation of plant genetic resources through the United Nations's Food and Agricultural Organization, and later through the Consultative Group for International Agricultural Research, both of which are headquartered in Europe. To conserve plant genetic resources, researchers must collect and store plant germplasm-the genetic material required to propagate a plant-usually in the form of a seed.

Teratogens are substances that may produce physical or functional defects in the human embryo or fetus after the pregnant woman is exposed to the substance. Alcohol and cocaine are examples of such substances. Exposure to the teratogen affects the fetus or embryo in a variety of ways, such as the duration of exposure, the amount of teratogenic substance, and the stage of development the embryo or fetus is in during the exposure. Teratogens may affect the embryo or fetus in a number of ways, causing physical malformations, problems in the behavioral or emotional development of the child, and decreased intellectual quotient IQ in the child. Additionally, teratogens may also affect pregnancies and cause complications such as preterm labors, spontaneous abortions, or miscarriages. Teratogens are classified into four types: physical agents, metabolic conditions, infection, and finally, drugs and chemicals.