Japan has experienced floods of fake knowledge about human reproduction in recent times. Most of them are created by professionals in the fields of obstetrics, gynecology, and reproductive medicine and spread widely through a mass media campaign backed by academic associations. Such a knowledge has also been used by the government as scientific evidence to justify encouragement of pregnancy and childbirth for young women .
“Egg aging” (卵子の老化) has been the key concept in the campaign. This concept is originally a term of biology for the degeneration of eggs (or female germ cells) owing to a long delay in the process of meiotic division . The concept is found in Japanese medical literature of the 1970s . In the early 2000s, it appeared in books targeting a general audience ; however, the arguments in that period were moderate and focused on the difficulties related to infertility treatment for women in their 40s. Before 2010, it was rare that the concept of egg aging was used with the same connotation as today.
In the 2010s, medical discourse shifted to emphasize the association between fertility decline and women's age. Professionals and mass media have created visual representations to emphasize how rapidly women's fertility decreases from their 20s to 30s.
As it acquired popularity, the concept widened its connotation. “Egg aging” has been mixed up with the findings that female germ cells are generated before a woman's birth and then continue to decrease in number . It has also been incorporated with reports that infertility treatment often fails with unidentified causes when the female patient is advanced in age . Consequently, the term “egg aging” today is not limited to the degeneration of germ cells, but covers a wide range of fertility problems experienced by women of an advanced age. It now serves as a magic phrase to represent many aspects of latent biological mechanisms of declining fertility .
In the course of the media campaign, fake knowledge about human reproduction has become popular in books, magazines, and websites giving an impression that it is based on scientific grounds. These are targeted at youths' perception of their body and thereby have an impact on their sexual behavior and family planning. We can regard this as a violation against reproductive rights because it disrupts the reproductive decision-making process with misinformation. It also damages public trust in the medical profession, which will eventually harm the social health system.
The “egg aging” campaign also has a political aspect because it has guided public attention to the linkage between age-related decline in biological fertility of persons and the birthrate decline in these decades of the country. Considering women's average age at first childbirth as old as 30 years today, people are surprised at the new biological knowledge about “egg aging.” They are worried that the recent generations would miss the opportunity to have children, without the awareness of the suitable period for pregnancy in their life. This idea brought about a political movement to educate people on egg aging. This movement is related not only to health matters, but also to a new pronatalist policy encouraging women to become pregnant earlier in life to stop the population shrinking of the Japanese society.
Since the Cabinet approved the new administration strategy described in the Outline of Measures against the Declining Birthrate  in March 20, 2015, such a pronatalist policy has been realized in school education, in “life-planning” guidance by local governments, and in messages broadcasted by mass media. Many visual representations of a dubious origin have been produced and used.
This brochure, Unscientific Visual Representations Used for the Egg Aging Campaign in 2010s Japan, is a product of the research project “Unscientific knowledge and the egg aging panic” (非科学的知識の生産・流通と「卵子の老化」パニック) funded by the Japan Society for the Promotion of Science (KAKENHI #17K02069 for fiscal 2017-2019). This project is run by Tanaka Sigeto, an associate professor at Tohoku University, to explore the courses, contexts, and consequences of the egg aging campaign. According to a literature survey of both academic and popular writings, this brochure introduces some instances of visual representations used in the campaign and explains how they have been widespread in the Japanese society to affect governmental policies and public opinions.
The project has collected information via social media, such as Twitter, besides literature reviews. This brochure owes the corporation with the informants. The author also thanks the corporation of those who participated in the group “高校保健・副教材の中止・回収を求める会”, which started in September 2015 to protest against the use of unscientific contents in a high school supplementary textbook for health education (see pages 6 and 10 of this brochure). Information is still wanted to trace the history of unscientific use of knowledge and to detect emergence of new discourses related to fertility issues (see p. 12).
(See http://tsigeto.info/18k#bib for the reference list.)
Egg aging campaign and Japanese pronatalist policy. (Unscientific Visual Representations Used for the “Egg Aging” Campaign in 2010s Japan, p. 2)