a blue embryo floating on a white background

THE EMBRYO PROJECT ENCYCLOPEDIA

Recording and contextualizing the science of embryos, development, and reproduction

Recently published

“Mortality and Morbidity in Transsexual Patients with Cross-Gender Hormone Treatment” (1989) by Henk Asscheman, Louis J. G. Gooren, and P. L. E. Eklund

Jan 14, 2026

In 1989, physicians Henk Asscheman, Louis J. G. Gooren, and P.L.E. Eklund published the article “Mortality and Morbidity in Transsexual Patients with…

Transgender Persons Hormones Estrogens

“Partial Paralysis from Reflex Irritation, Caused by Congenital Phimosis and Adherent Prepuce” (1870), by Lewis Albert Sayre

Jan 14, 2026

In 1870, Lewis Albert Sayre, an orthopedic surgeon, published “Partial Paralysis from Reflex Irritation, Caused by Congenital Phimosis and Adherent…

Paralysis Phimosis Circumcision, Male

Thesis: Uterine Technologies: Ethical and Social Considerations

Aug 14, 2025

Over the past few decades, female infertility rates have been steadily increasing. As of 2025, various infertility treatments, including IVF and…

Reproduction Women's Health Biology

Recent news

Browse by subject

Abortion Development Embryology Ethics Eugenics Evolution Genetics Law Reproduction Sex and gender Technology Stem cells

an illustration of an embryo and a uterus

See what's new over at Embryo Tales, our partnership with

ask a biologist

Go to site

The Encyclopedia has a rich collection of historical photographs and custom illustrations View images

The Embryo Project is supported by the National Science Foundation, Arizona State University, Center for Biology and Society, the Max Planck Institute for the History of Science in Berlin, and the MBL WHOI Library.