Progestin is a synthetic form of progesterone, a naturally occurring hormone, which plays an important role in the female reproductive cycle. During the 1950s two types of progestin that were later used in birth control pills were created, norethindrone and norethynodrel. In 1951 Carl Djerassi developed norethindrone at Syntex, S.A. laboratories located in Mexico City, receiving a patent on 1 May 1956. In 1953 Frank Colton developed norethynodrel at G.D. Searle and Company laboratories located in Chicago, receiving a patent on 29 November 1955. These two types of synthetic progesterone are important to the history of embryology because they facilitated the development and creation of the birth control pill, which changed the way people viewed birth control and revolutionized women's birth control methods.
In 2011, United Kingdom pharmaceutical company GlaxoSmithKline released Cervarix, a vaccination series protecting girls and women from two strains of Human Papillomavirus, or HPV. HPV, a sexually transmitted infection, can present in men and women without symptoms, or may cause symptoms such as genital warts. There is a link between HPV and cervical, vaginal, anal, head, neck, and face cancers, and Cervarix can reduce genital cancers in girls and women, particularly cervical cancer. Gardasil, a similar vaccination against HPV, approved by the United States Food and Drug Administration, or FDA and available in the US in June 2006 was on the market five years prior to Cervarix’s approval in October 2009. In 2014, because of the heightened cost and lesser coverage, the US market discontinued Cervarix, but as of 2019, it remains popular in Europe, especially in the United Kingdom. Cervarix is the first HPV vaccine administered in China.
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.
The development of the obstetric ultrasound has allowed physicians and embryologists to obtain a clear picture of the developing human embryo and fetus during pregnancy. Obstetric ultrasonography, often referred to as ultrasound, is a technology that uses sound waves to produce images of structures inside the human body. A handheld probe emits sound waves, which are reflected back by the different structures within the body. These reflected sound waves are converted into electric signals that are detected by a transducer, which then produces two-dimensional images that can be interpreted by medical professionals. Ultrasound technology has become a sophisticated, high-resolution diagnostic imaging tool used widely in medicine, especially obstetrics.
Plan B is a progestin-only emergency contraceptive pill (ECP) that can be taken within seventy-two hours of unprotected sex in order to prevent an unwanted pregnancy. Plan B was created in response to the United States Food and Drug Administration's (US FDA) 1997 request for new drug applications (NDAs) for a dedicated ECP product, and was approved for sales in the US in 1999. Duramed, a subsidiary of Barr Pharmaceuticals, manufactures Plan B for The Women's Capital Corporation (WCC), which owns the patent for Plan B. This technology is important in part because it expands women's reproductive rights by giving them greater control over their fertility. The mechanism of action of Plan B also raises questions about the moral status of the zygote.
Charles Manning Child designed an experimental test, the susceptibility assay, to measure the effects of different toxins on developmental processes. The susceptibility assay measured an organism s vulnerability to death when it was submerged in a noxious solution. The assay involved immersing an organism in a solution that contained a depressant or inhibitory substance, such as alcohol, and then measuring the responses of the organism. Child interpreted these measurements as revealing information about the relative levels of metabolic activity within the organism. Child predicted an organism's susceptibility to death should vary directly with its metabolic rate. An organism with a high metabolic rate would be expected to die more quickly in a noxious chemical solution than an organism with a lower metabolic rate: the higher the rate, the more quickly death should ensue. He also predicted young organisms should have higher metabolic rates than older organism, since children were known to metabolize drugs more quickly than adults.
Assisted reproductive technologies (ART) are a collection of different techniques designed to help those who are infertile achieve a successful pregnancy. The most popular technology currently in use is in vitro fertilization (IVF), but others include gamete intrafallopian transfer (GIFT), zygote intrafallopian transfer (ZIFT), intrauterine insemination (IUI), and intracytoplasmic sperm injection (ICSI). Although not encompassed under the umbrella term of ART, there are also various hormonal medications that can induce ovulation such as clomiphene citrate that can either be used alone to help women conceive, or used in conjunction with the above techniques. Infertility is a problem that has affected people throughout history, but it was only in the last half of the twentieth century that medical research developed technologies to help those who are infertile become pregnant.
For more than 2000 years, embryologists, biologists, and philosophers have studied and detailed the processes that follow fertilization. The fertilized egg proliferates into cells that begin to separate into distinct, identifiable zones that will eventually become adult structures through the process of morphogenesis. As the cells continue to multiply, patterns form and cells begin to differentiate, and eventually commit to their fate. This progression of events can be examined by following the developmental path of each progenitor cell and creating a two-dimensional representation where cell location and fate can be labeled and marked. Fate mapping is a method for tracing cell lineages and a fundamental tool of developmental biology and embryology.
James Marion Sims developed a treatment for vesico-vaginal fistulas in Montgomery, Alabama in the 1840s. Vesico-vaginal fistulas were a relatively common condition in which a woman's urine leaked into her vaginal cavity from her bladder, and many regarded the fistulas as untreatable during the early 1800s. After years of efforts to repair the fistulas with myriad tools, techniques, and procedures, Sims developed the speculum and a vaginal examination position later named for him. He also popularized the use of silver metal sutures to treat and cure women who had vesico-vaginal fistulas. Sims's surgical cure for vesico-vaginal fistulas eased both the social stigma and physical discomfort of many affected women. Though current treatments of vesico-vaginal fistulas have evolved since the nineteenth century, some of the basic principles utilized by Sims have been incorporated into present-day surgeries. In particular, Sims stressed the significance of continual bladder drainage after the operation.
"MicroSort, developed in 1990 by the Genetics and IVF Institute, is a form of pre-conception sex selection technology for humans. Laboratories located around the world use MicroSort technology to help couples increase their chances of conceiving a child of their desired sex. MicroSort separates male sperm cells based on which sex chromosome they contain, which results in separated semen samples that contain a higher percentage of sperm cells that carry the same sex chromosome. The technology ultimately enables couples to choose the sex of their future child by choosing semen samples that predominately contain sperm with the X chromosome for a female or Y chromosome for a male. MicroSort technology is a sperm sorting technique that provides couples worldwide a means of pre-conception sex selection.