Karl Oskar Illmensee studied the cloning and reproduction of fruit flies, mice, and humans in the US and Europe during the twentieth and twenty-first centuries. Illmensee used nuclear transfer techniques (cloning) to create early mouse embryos from adult mouse cells, a technique biologists used in later decades to help explain how embryonic cells function during development. In the early 1980s, Illmensee faced accusations of fraud when others were unable to replicate the results of his experiments with cloned mouse embryos. Illmensee also worked with human embryos, investigating how embryos split to form identical twins.

John Hunter studied human reproductive anatomy, and in eighteenth century England, performed one of the earliest described cases of artificial insemination. Hunter dissected thousands of animals and human cadavers to study the structures and functions of organ systems. Much of his anatomical studies focused on the circulatory, digestive, and reproductive systems. He helped to describe the exchange of blood between pregnant women and their fetuses. Hunter also housed various natural collections, as well as thousands of preserved specimens from greater than thirty years of anatomy work. Hunter's work developed practices in reproductive and reparative surgery and furthered the study of human anatomy and physiology.

The Malthusian League, founded in London, England, in 1877 promoted the use of contraception to limit family size. Activists Charles Bradlaugh and Annie Besant established the Malthusian League after they were arrested and exonerated for publishing a pamphlet describing techniques to prevent pregnancy. Founders based the league on the principles of Thomas Malthus, a British nineteenth century economist, who wrote on the perils of a population growing beyond the resources available to support it. The Malthusian League advocated for limiting family size voluntarily through contraception to avoid the overpopulation and poverty cautioned in Malthus’ work. After fifty years, the Malthusian League closed due to the increasing disapproval for Malthus’s economic theories of population and poverty. However, the Malthusian League’s activism during the late nineteenth and early twentieth centuries led to more tolerant views of contraception and family planning in Great Britain in the twentieth century.

Virginia Apgar and colleagues wrote “Evaluation of the Newborn Infant—Second Report” in 1958. This article explained that Apgar’s system for evaluating infants’ condition after birth accurately predicted the health of infants. Apgar had developed the scoring system in 1953 to provide a simple method for determining if an infant needed medical attention after birth. The research team, working at Columbia University College of Physicians and Surgeons in New York City, New York, studied the Apgar scores of over 15,000 infants from Sloane Hospital for Women in New York City, New York, over a period of five years. In “Evaluation of the Newborn Infant—Second Report,” Apgar and colleagues established that Apgar scores correlated with infants’ health directly after birth and indicated when medical personnel should treat the infant.

In Maureen Kass v. Steven Kass (1998), the Court of Appeals of New York in Albany, New York, ruled that the state should generally consider IVF consent forms signed by participants in an in vitro fertilization (IVF) program valid, binding, and enforceable in the event of a dispute. The court indicated that decisions regarding the handling of cryopreserved pre-zygotes, often called preembryos, contained within these consent forms should be upheld. Although Steven and Maureen Kass had signed IVF consent forms agreeing to donate unused preembryos to research, during their divorce Maureen argued for custody of the preembryos. The New York Court of Appeals ruled in favor of Steven Kass and concluded that the informed consent forms signed by the former couple had clearly manifested the coupleÕs mutual intent to donate any preembryos to research in the event of a dispute.

Leon Chesley studied hypertension, or high blood pressure, in pregnant women during the mid-twentieth century. Chesley studied preeclampsia and eclampsia, two hypertensive disorders found in approximately five percent of all US pregnancies. In New Jersey and New York, Chesley devoted over forty years to researching preeclampsia and eclampsia. Chesley conducted several long-term studies using the same group of women beginning from their pregnancies. Chesley’s multi-decade research led to more accurate diagnosis of preeclampsia and eclampsia in pregnant women and significantly reduced the mortality of pregnant women due to hypertensive diseases.

NovaSure is a device for endometrial ablation, which is a procedure that removes the endometrium, that the US Food and Drug Administration, or FDA, approved for use on 28 September 2001. Endometrium is the tissue that lines the uterus. NovaSure destroys the endometrium by sending electric beams at the endometrium. Hologic, a medical technology company concerned with women’s health, developed NovaSure to treat menorrhagia, or heavy bleeding during menstruation. Menorrhagia is a common symptom of endometriosis. Endometriosis is the growth of the endometrium outside of the uterus. While NovaSure is not a treatment that doctors use to directly treat endometriosis, the procedure may help alleviate heavy bleeding during menstruation, which may improve a patient’s quality of life as heavy menstrual bleeding is often associated with high levels of anxiety and low levels of confidence.

In the nineteenth century, obstetricians in Europe began to construct devices to incubate infants in increasingly controlled environments. The infant incubator is a medical device that maintains stable conditions and a germ free environment for premature infants born before the thirty-seventh week of pregnancy. Records show that physicians had used infant incubators since 1835. However, Jean-Louis-Paul Denuce, a physician who worked in Bordeaux, France, first published about incubator technology in 1857. Carl Crede released his incubator model in Germany in 1860 and Stephane Tarnier further developed the model in 1884. The infant incubator technology provides a stable environment for premature infants and helps keep them alive.

John Chassar Moir lived in Scotland during the twentieth century and helped develop techniques to improve the health of pregnant women. Moir helped to discover compounds that doctors could administer to women after childbirth to prevent life-threatening blood loss. Those compounds included the ergot alkaloid called ergometrine, also called ergonovine, and d-lysergic acid beta-propanolamide. Moir tested ergometrine in postpartum patients and documented that it helped prevent or manage postpartum hemorrhage in women. Moir also developed methods to treat tears between the bladder and the vagina, called vesico-vaginal fistulas, that occur due to complications of childbirth, and that cause urinary incontinence in women who have them.

Pierre Constant Budin worked in France to improve the lives of newborns and their mothers during the late nineteenth century. Budin stressed the importance of proper nutrition in infants and educated new mothers on breastfeeding and infant care. Budin established infant care facilities and created a nutritional check-up system for infants. Budin helped design early artificial nipples, breast pumps, and incubators for premature newborns. He also began the practice of consulting with new mothers after they gave birth, redefining the roles of obstetricians.