Leonardo da Vinci's embryological drawings of the fetus in the womb and his accompanying observational annotations are found in the third volume of his private notebooks. The drawings of Leonardo's embryological studies were conducted between the years 1510-1512 and were drawn with black and red chalk with some pen and ink wash on paper. These groundbreaking illustrations of the fetus reveal his advanced understanding of human development and demonstrate his role in the vanguard of embryology during the Renaissance. His famous embryological drawings of the fetus have since been collected and held in the Royal Collection at Windsor Castle in England.

The embryological treatise De formatione ovi et pulli (On the Formation of the Egg and of the Chick) was written by anatomist and embryologist Girolamo Fabrici and published in Padua posthumously in 1621. The book was edited by Joahannes Prevotius and is separated into two parts that describe Fabrici's observations and assumptions on embryology and combine the traditional knowledge of his predecessors with his own first-hand anatomical observations. Each part is separated into three chapters: the first part concerns the formation of the egg while the second part of the treatise covers the generation of the chick within the egg.

Girolamo Fabrici, known as Hieronymus Fabricius in Latin, was given the surname Aquapendente from the city where he was born, near Orvieto, Italy. Born in 1533, Fabrici was the eldest son of a respected noble family, whose coat of arms appears as an illustration in the title page of Fabrici's book on embryology, De formato foetu. Little is known of Fabrici's parents. His father is recorded as Fabricio, and Fabrici is said to have been named for his paternal grandfather. Fabrici influenced many scientists and physicians of his time to consider embryology as a legitimate and independent subject, and his two illustrated treatises on embryology are a remarkable legacy of his investigations on the development and comparative anatomy of fetuses.

The Center for Reproductive Health was a fertility clinic run by a partnership of world-renowned fertility specialists from 1986 to 1995. The Center operated at three clinic locations under affiliation with the University of California Irvine 's Medical Center (UCIMC). The Center's renowned specialists and medical success stories attracted clients worldwide until evidence of highly unethical practices conducted by doctors there resulted in over one hundred lawsuits against the University. At issue was the doctors' misappropriation and unauthorized use of eggs and embryos. The three partners of the Center were indicted for mail fraud, for billing insurance companies for work not performed, and for violating California State legislation requiring consent to use eggs and embryos and outlawing egg and embryo theft. The three partners indicted for the unethical practices at the Center were Sergio Stone, a uterine surgery and hormonal treatment specialist, José Balmaceda, a Rockefeller Foundation fellowship award winner in reproductive endocrinology, and Ricardo Asch, director of the clinics and inventor of the gamete intrafallopian transfer (GIFT) assisted reproduction technique.

Various techniques constitute assisted reproduction, one of which is gamete intra-fallopian transfer (GIFT). The first example of GIFT involved primates during the 1970s; however, the technology was unsuccessful until 1984 when an effective GIFT method was invented by Ricardo Asch at the University of Texas Health Sciences Center and the procedure resulted in the first human pregnancy. The GIFT technique was created in hopes of generating an artificial insemination process that mimicked the physiological sequences of normal conception. The technique was further advanced at the Center for Reproductive Health at the University of California, Irvine, when Asch and his associate Jose Balmaceda employed a newly developed catheter into the GIFT procedure that eliminated the need for general anesthesia in the later stages of the procedure.

José Pedro Balmaceda was born 22 August 1948 in Santiago, Chile. His mother Juanita owned a women's boutique in the city and his father José was a successful owner of several timber mills. He grew up with five sisters who remained in Santiago all their lives. Balmaceda attended the college preparatory school San Ignatius where he met Sergio Stone, his future partner at the Center for Reproductive Health fertility clinic in the University of California Irvine Medical Center. In 1974 Balmaceda graduated from Catholic University Medical School and became a resident at the University of Chile hospital where he worked in obstetrics and gynecology.

Sergio Cereceda Stone was born 16 April 1942 in the coastal city of Valparaiso, Chile. Stone's mother Luz was a housewife and caretaker for Sergio and his younger brother Lionel; his father Sergio served among the country's twenty appellate court judges. In the early 1950s Stone's father relocated the family to Santiago to further his law career. There Stone attended the Jesuit elementary and high school Collegio San Ignatius, finished in the top ten percent of his class, and met José Balmaceda, his future coworker at the Center for Reproductive Health in Irvine, California. From San Ignatius, Stone went on to the University of Chile Medical School where he finished his obstetrics and gynecology residency. In 1969 he accepted a grant from the Ford Foundation for advanced research in endocrinology.

Leonardo da Vinci was born on 15 April 1452, the illegitimate son of a young peasant girl by the name of Caterina and Ser Piero da Vinci, a well-renowned Florentine notary. Leonardo lived in Italy in the town of Vinci until his late teens and received a simple education in reading and writing as well as some training in mathematics and engineering. Although he was socially excluded by birthright from almost every profession and prohibited from attending any formal university, Leonardo went on to become a celebrated scientist, artist, and engineer. His research in mathematics, mechanics, cosmology, hydrodynamics, biology, botany, geology, geography, and anatomy signify his ingenious skills as a polymath. Among his numerous contributions, Leonardo is most famous for his artwork, anatomical drawings, and imaginative mechanical structures that influenced his natural philosophy and served to frame his early embryological studies. His embryological annotations and drawings of the fetus represent his groundbreaking curiosity and scientific method in depicting the human form in utmost detail.

The embryological treatise De formato foetu (The Formed Fetus) was written by anatomist and embryologist Girolamo Fabrici. There is no conclusive evidence regarding the first date of publication and what is listed on many copies ranges from 1600-1620, with speculation that the dates were altered by hand. Most forms of the book are dated 1600 and were issued by Franciscus Bolzetta who sold many copies in Venice and whose name appears on the engraved title-page. There is also verification of the book being printed in Padua by Laurentius Pasquatus in 1604. This treatise was the last publication to be issued before Fabrici retired from his teaching position at the Univeristy of Padua and it was the last anatomical work of his to be published during his lifetime. The book illustrates Fabrici's views on the anatomy of the fetus and uterus and demonstrates his struggle between accepting traditional authority and relying on his own experience in his investigations in embryology.

Ricardo Hector Asch was born 26 October 1947 in Buenos Aires, Argentina, to a lawyer and French professor, Bertha, and a doctor and professor of surgery, Miguel. Asch's middle-class family lived among the largest Jewish community in Latin America, where a majority of males were professionals. After his graduation from National College No. 3 Mariano Moreno in Buenos Aires, Asch worked as a teaching assistant in human reproduction and embryology at the University of Buenos Aires School of Medicine where he received his medical degree in 1971.