The Whelan Method of Sex Selection is a method for increasing a couple’s probability of conceiving an infant of the desired sex through timing intercourse. Elizabeth Whelan, a public health researcher, suggested that couples only have intercourse at specific times during the woman’s menstrual cycle based on whether they wanted a female or male infant. Whelan published her method in her book, Boy or Girl, in 1977. During the mid-to-late twentieth century, researchers offered other methods of timing intercourse for sex selection, but their results were based on studies of artificial insemination, rather than naturally occurring pregnancies. Whelan claimed her method was supported by natural insemination studies and that it worked for couples trying to conceive an infant of a particular sex.
Physician researchers Edgar Rey Sanabria and Héctor Martínez-Gómez developed the Kangaroo Mother Program in Bogotá, Colombia, in 1979, as an alternative to conventional incubator treatment for low birth weight infants. As of 2018, low birth weight and its associated complications are the leading causes of infant death, especially in developing and underdeveloped countries where access to technology and skilled healthcare providers is limited. Kangaroo Mother Care is a simple and low cost method for treating low birth weight infants. Even though researchers developed Kangaroo Mother Care for infants born in hospitals with limited resources, they demonstrated that the method could be just as effective as conventional treatments. Kangaroo Mother Care changed the standard of care for low birth weight infants, making life-saving medical treatments accessible to thousands of infants in developing and undeveloped countries.
Matthew Meselson, Franklin Stahl, and Jerome Vinograd, developed cesium chloride, or CsCl, density gradient centrifugation in the 1950s at the California Institute of Technology, or Caltech, in Pasadena, California. Density gradient centrifugation enables scientists to separate substances based on size, shape, and density. Meselson and Stahl invented a specific type of density gradient centrifugation, called isopycnic centrifugation that used a solution of cesium chloride to separate DNA molecules based on density alone. When Meselson and Stahl developed the technique in the mid-1950s, scientists had no other way to separate macromolecules that were of similar size but varied in density. Meselson and Stahl employed their method to determine how DNA replicates, became known as the Meselson-Stahl experiment. Density gradient centrifugation using cesium salts allowed scientists to isolate DNA and other macromolecules by density alone.
Mammography or mastography is an imaging technology used in the twentieth century for the detection of breast cancer and other breast abnormalities. Breast cancer is an abnormal growth in breast tissue that can spread to other parts of the body and cause death. Breast cancer affects about twelve percent of women worldwide. In the twenty-first century, mammography is one of the most accurate tools for screening and diagnosing breast cancer. A mammogram is the image created by sending low-level X-rays through breast tissue then filmed or a digital recorder captures the image, which a radiologist analyzes. A Senographe is the instrument used to create the mammogram to screen for breast cancer and other breast diseases. Mammography significantly decreased the number of deaths from breast cancer, but it can also give false positive results and cause physicians to over diagnose that may result in treatment for diseases women do not have.
Throughout history methods involving urine have been a popular way to test for pregnancy. Early ideas ranged from simply observing the color of a woman's urine to the notion that the urine of pregnant women contains special crystals or secretions. Indeed, pregnancy testing can be traced back to 1350 BCE in Ancient Egypt. A written document from the time describes a process in which a woman would urinate on wheat and barley seeds over several days and, depending on which plant grew, both the woman's pregnancy status and the sex of the fetus could be determined. In 1905, British physiologists Ernest Starling and William Bayliss were the first to isolate special hormone markers found in the urine of pregnant women.
Intracytoplasmic Sperm Injection (ICSI) is an assisted reproductive technique (ART) initially developed by Dr. Gianpiero D. Palermo in 1993 to treat male infertility. It is most commonly used in conjunction with in vitro fertilization (IVF) or a less commonly used technique called zygote intrafallopian transfer (ZIFT). In natural fertilization, the sperm must penetrate the surface of the female egg, or oocyte. When the male has a fertility problem such as low sperm count, malformed sperm shape, or sperm immobility, there is a significant decrease in the chance a healthy sperm will penetrate the outer surface of the oocyte. Other fertility problems ICSI can be used to overcome include the sperm having trouble attaching to the egg or the male having a blockage in his reproductive tract preventing normal ejaculation. In this procedure, the physician first obtains the sperm and oocytes from the male and female and then manually injects the sperm through a needle into the oocyte to fertilize it in an injection plate. The physician then places the fertilized egg into the female s uterus for implantation, following IVF procedures.
Three-dimensional anatomical models have long been essential to the learning of science and lend a sense of "control" to those practicing in the field. As the development of embryology grew in importance during the late 1800s, so did the need for models to show intricate details of embryos. Embryologists such as Wilhelm His, Ernst Haeckel, and Oscar Hertwig all initially constructed their own wax models of embryos but later handed over the modification and reproduction of their models to various "plastic artists." The most renowned among these artists was Adolf Ziegler.
Enovid was the first hormonal birth control pill. G. D. Searle and Company began marketing Enovid as a contraceptive in 1960. The technology was created by the joint efforts of many individuals and organizations, including Margaret Sanger, Katharine McCormick, Gregory Pincus, John Rock, Syntex, S.A. Laboratories, and G.D. Searle and Company Laboratories. Although there were many pieces and contributors to the final product, it was first conceived of and created by Gregory Pincus and Margaret Sanger through the Worcester Foundation in Worcester, Massachusetts, and was distributed by Searle, located in Chicago. This technology is important to the history of embryology because it changed the way people viewed birth control and revolutionized women's birth control methods. There is an extensive literature on the cultural and societal effects of the pill; for example, the effect it had on women's health care and how it changed perceptions of female sexuality.
A hysterectomy is the surgical removal of a woman's uterus. For many women, a hysterectomy comes as a solution to health problems as diverse as abnormal bleeding to reproductive cancers. First performed in the early 1800s, this procedure has evolved in terms of both technique and popularity. The first successful abdominal hysterectomy was performed by Ellis Burnham in Lowell, Massachusetts, in 1853, although earlier attempts were made in the 1840s. These first hysterectomies were not performed under effective anesthetics-it was not until later in 1853 that a patient of surgeon Gilman Kimball would benefit from the use of chloroform. The hysterectomy of the modern era has become a common and much safer procedure-so common, in fact, that many believe that the hysterectomy is performed too often and in place of other, perhaps healthier, alternatives. In addition to its inherent surgical risks, a hysterectomy also makes it impossible for a woman to have further children.
Endoscopy is a medical procedure that enables the viewing and biopsy of, and surgery on, internal tissues and organs. Endoscopic examinations are characterized by the introduction of a tube containing a series of lenses into the body through either an incision in the skin or a natural opening or cavity. During the mid-twentieth century, photographer Lennart Nilsson used endoscopes to capture the now-familiar images of embryos and fetuses. Examples of endoscopic procedures beyond embryonic observation include colonoscopy, cystoscopy, neurosurgery, endoscopic sinus surgery, appendectomy, and many more.