Arnold Henry Kegel worked and carried out research in the medical field of gynecology in the US during the twentieth century. Through his work, Kegel was one of the first to describe what researchers call Kegel exercises, which strengthen the pelvic floor muscles, or the muscles that extend from the pelvis to the tailbone and support the internal reproductive organs, bladder, and bowel. Kegel observed that weakened pelvic floor muscles could cause disorders like urinary incontinence, when a person loses partial or complete bladder control, and organ prolapse, which is when the pelvic floor cannot adequately support organs in the pelvic region, causing them to fall out of place. Kegel was also one of the first to find that females could strengthen their pelvic floors through exercises, which provided an alternative to invasive surgeries to repair those muscles. Kegel helped discern the role that the pelvic floor plays in reproductive health, and he developed simple methods to strengthen the pelvic floor that could, in turn, improve sexual and reproductive health in females and males of all ages.

Hideyo Noguchi researched bacteria, including Treponema pallidum, the bacterium that causes syphilis, in Japan and the US during the early 1900s. Syphilis is a bacterial infection that spreads primarily through sexual transmission and can cause symptoms such as rashes, genital sores, and even organ damage. Noguchi recognized that Treponema pallidum causes neurosyphilis, which is when the syphilis infection spreads to the covering of the brain, the brain itself, or the spinal cord. Before Noguchi’s work, researchers knew about Treponema pallidum and the symptoms of the disease but did not know that untreated syphilis could lead to neurosyphilis. Additionally, Noguchi worked to alter and improve methods to diagnose syphilis. Noguchi’s work helped future researchers and doctors better diagnose people with syphilis, assisted them in understanding how to treat the disease’s long-term side effects, and helped them reduce the spread of syphilis, including between pregnant people and their fetuses.

Henry Hubert Turner was a physician and researcher who studied hormones and human development in Oklahoma City, Oklahoma, during the twentieth century. He was one of the first people to classify Turner syndrome, which is a genetic condition that occurs when someone has a specific atypical chromosomal pattern, and as of 2024, affects one in 1,500 to 2,500 female births. Turner syndrome results in a biological female completely or partially missing one of their X chromosomes. Many researchers label it an intersex condition, or a condition in which someone has atypical male or female sex characteristics, such as different sex chromosome patterns. During his career, Turner encountered multiple patients with a specific set of symptoms, including stunted sexual development, webbed neck, and elbow deformities, and he was unable to place those symptoms under one existing diagnosis. So, he categorized those symptoms as a new syndrome, which researchers later named Turner syndrome. By identifying Turner syndrome as a developmental condition, Turner helped future physicians develop treatments and diagnostic tools that can improve the lives of individuals with various developmental disorders.

George Herbert Hitchings researched and developed medications that targeted specific parts of DNA replication processes to treat cancers and various illnesses in the US during the twentieth century. By studying DNA analogs, or manmade substances that resemble the structure of naturally occurring DNA components and are capable of inhibiting DNA replication, Hitchings promoted a novel approach to pharmaceutical research and drug development, known as rational drug design. Using that novel approach, Hitchings and his research team created acyclovir, one of the first medications to effectively treat herpes, a condition that can be sexually transmitted but can also be passed from mother to child, causing life-threatening illness in infants. Hitchings also contributed to the development of cancer treatments, immunosuppressant medications, anti-viral medications, and anti-malarial medications. Hitchings’s research on DNA analogs established rational drug design as a method to create new pharmaceutical drugs, some of which treat sexually transmitted illnesses.

Christine Jorgensen was a transgender woman and activist in the United States who lived during the twentieth century. She was one of the first US citizens to publicly disclose her gender transition from male to female through gender-affirming surgery and hormone replacement therapy. By 1949, when Jorgensen began her transition, few individuals had undergone gender transition. Various popular media outlets reported on Jorgensen’s gender transition and surgery, which allowed Jorgensen to educate the American public on topics such as gender identity and sexual orientation. Jorgensen authored an autobiography in 1967, which detailed the journey of her life from early childhood to the end of her forties. Although many transgender people continue to fight for acceptance and equality in the US as of 2024, Jorgensen’s advocacy and activism increased transgender awareness for the general public at a time when existing and living openly as a transgender person received little recognition and support.

Alan Osborne Trounson is a scientist from Australia who studies embryology and stem cells. His research has improved the success rates of in vitro fertilization, or IVF. IVF is a medical procedure in which scientists fertilize an egg cell with sperm outside of the body, often in a laboratory petri dish, then transfer the fertilized egg to a woman’s uterus to start pregnancy. Trounson also researched embryonic stem cells, or stem cells collected from embryos, and their potential for treating injuries and diseases. Additionally, Trounson led the Californian Institute for Regenerative Medicine, or CIRM, one of the largest agencies to fund stem cell research in California, from 2007 to 2014. Over the course of his career, Trounson developed several techniques that improved the effectiveness of IVF, including fertility treatments and cryopreservation, and supported stem cell research as a scientist and administrator.

David Phillip Vetter was born with X-linked severe combined immunodeficiency disorder, or X-SCID, and spent most of his life in an isolated sterile bubble to stay alive. X-SCID is a genetic disorder that causes a deficiency of protective immune cells that fight infections, which increases susceptibility to disease. Vetter’s weakened immune system meant that he would die if he encountered any bacteria, viruses, or other germs, so his doctors placed him in a sterile isolator, a plastic bubble that prevented germs from entering. Vetter was thus a germ-free human, meaning he developed in the absence of germ exposure. He grew up in his sterile isolator, earning him the nickname “Bubble Boy,” and lived there until his death in 1984 at age twelve. Researchers frequently studied Vetter’s development because he was one of the first individuals with X-SCID to survive over a year after birth. As one of the first germ-free humans, Vetter provided an opportunity for researchers to study what happens when a human develops without germs and his cells helped them determine the genetic cause of X-SCID.

Pierre Franco was a surgeon in Europe in the sixteenth century who developed a variety of surgical procedures, including some to repair hernias, cleft lips, and bladder stones. A hernia occurs when an internal organ protrudes through a weak spot in a muscle or tissue, typically in the abdomen, which can cause severe pain, nausea, and vomiting. A cleft lip is a congenital abnormality where the tissues of the upper lip and roof of the mouth do not form properly as the fetus develops during pregnancy, causing problems with eating and speaking. Bladder stones are hard masses of minerals that build up from a person’s urine and form in their bladder, often causing pain or bleeding during urination. Franco described the congenital origin of the cleft lip and was one of the first to develop a repairing procedure for hernias without the removal of genitals. As of 2024, surgeons have continued to innovate upon many of Franco’s surgical procedures, including those to repair hernias and cleft lips, to help children born with congenital defects and other patients in need of surgery.

Philippe Ricord was a nineteenth-century physician and surgeon in France who studied syphilis and demonstrated that it is different from gonorrhea. As of 2024, researchers recognize that syphilis and gonorrhea are both sexually transmitted infections, or STIs. However, the bacterium Treponema pallidum causes syphilis, leading to symptoms such as sores and fever, whereas the bacterium Neisseria gonorrhoeae causes gonorrhea and leads to different symptoms such as discharge from the urethra. Before Ricord, researchers thought syphilis and gonorrhea were the same disease. Ricord, through observation and experimentation, distinguished syphilis from gonorrhea and arranged the stages of syphilis into primary, secondary, and tertiary, each associated with different symptoms and levels of severity. By distinguishing syphilis from other STDs and accurately categorizing its stages, Ricord helped researchers better understand how to treat syphilis, a disease that can be transmitted from mother to child, causing life-threatening illness in infants.

Robert Lawson Tait was a physician who practiced abdominal surgery in the United Kingdom during the late nineteenth century. Physicians and historians credit Tait with introducing a number of gynecologic surgeries, or surgeries related to women’s reproductive health. Those included procedures for treating abscesses, removing ovaries, and fallopian tubes, and treatment of the gallbladder. Beyond his work as a surgeon, Tait advocated against vivisection, which is the practice of medical experimentation on living animals. Tait also argued for strict cleanliness during surgery as well as a more specific focus on performing surgeries to treat diseases of the female reproductive system. Tait’s surgical techniques and advocacy not only aided in the development of hygiene in surgery, increasing patient survival, but also helped develop the field of gynecology, which contributed to a centralized focus on the health of the female reproductive system.