Gender-affirming mastectomy is a type of surgery that removes breast tissue, tightens the skin, and can adjust nipple placement to provide the desired results of a more masculine-looking chest. Mastectomies started as a way for surgeons to remove breast cancer and tumors from the breast tissue. However, as of 2022, surgeons also use the procedure as a means of gender-affirming surgery for transgender and non-binary, hereafter TNB, individuals. If a person identifies as transgender, their gender identity differs from the sex they were assigned at birth and the gender they were most likely raised as, which can produce gender dysphoria, a condition that can last a lifetime. Non-binary individuals may have a similar experience, but they identify outside of or between the identifiers of man and woman. Gender-affirming mastectomy, sometimes called top surgery, improves the quality of life for people who seek the appearance of a masculine chest to both better integrate themselves into society and lessen the mental and emotional burden of gender dysphoria.

In 2014, Flor M. Munoz and colleagues published “Safety and Immunogenicity of Tetanus Diphtheria and Acellular Pertussis (Tdap) Immunization During Pregnancy in Mothers and Infants: A Randomized Clinical Trial,” hereafter “Tdap Immunization During Pregnancy,” in the Journal of the American Medical Association. The authors conducted a study to determine how Tdap immunization affected the mother and infant’s immune response to the common childhood diseases tetanus, diphtheria, and pertussis. They found that Tdap immunization did not lead to an increased risk of adverse health events. Furthermore, maternal Tdap immunization provided the infant with protective levels of pertussis antibodies after delivery and did not affect the infant differently from the DTaP vaccination series, which is the version of Tdap for young children. The authors’ findings in “Tdap Immunization During Pregnancy” supported the United States Centers for Disease Control and Prevention’s, or CDC’s, recommendation for pregnant women to receive the Tdap vaccine to prevent disease in mother and infant.

Nuclear magnetic resonance imaging (MRI) is a technique to create a three-dimensional image of a fetus. Doctors often use MRIs to image a fetuses after an ultrasound has detected an, or has been inconclusive about an, abnormality. In 1983 researchers in Scotland first used MRI to visualize a fetus. MRIs showed a greater level of fetal detail than ultrasound images, and researchers recognized the relevance of this technique as a means to gather information about fetal development and growth. Researchers later used the technology to take measurements of the uterus, placenta, amniotic fluid, and fetus during the first trimester of pregnancy. MRI provided doctors with a non-invasive method to diagnose and treat fetal abnormalities and maternal conditions such as pre-eclampsia.

Hormone releasing intrauterine devices or hormonal IUDs are contraceptive devices placed in a woman’s uterus to prevent pregnancy by continuously releasing a low dose of certain hormones. Jouri Valter Tapani Luukkainen, a medical researcher at the University of Helsinki, introduced the first hormonal IUD in 1976. Luukkainen’s IUD was a plastic device shaped like a capital T. The horizontal shafts of the IUD held a reservoir of the hormone Levonorgestrel that the IUD slowly released at a constant rate over the IUD’s lifetime, allowing the hormonal IUD to remain effective for five to seven years. Women can use hormonal IUDs for long term contraception that requires no maintenance on the part of the user. The hormonal IUD provides women an option for reliable long-term birth control that does not require maintenance to remain effective.

Ignacio Vives Ponseti developed a noninvasive method for treating congenital club foot in the US during the late 1940s. Congenital club foot is a birth deformity in which one or both of an infant's feet are rotated inward beneath the ankle, making normal movement rigid and painful. Ponseti developed a treatment method, later called the Ponseti method, that consisted of a series of manipulations and castings of the club foot performed in the first few months of life. The Ponseti method provided a non-surgical treatment that generally resulted in better long-term outcomes than the surgical procedures that doctors used prior to his work. Ponseti's method for treating congenital club foot improved the quality of life for patients born with the deformity, and his work led researchers to study fetal foot tissues.

The use of blood in forensic analysis is a method for identifying individuals suspected of committing some kinds of crimes. Paul Uhlenhuth and Karl Landsteiner, two scientists working separately in Germany in the early twentieth century, showed that there are differences in blood between individuals. Uhlenhuth developed a technique to identify the existence of antibodies, and Landsteiner and his students showed that humans had distinctly different blood types called A, B, AB, and O. Once doctors differentiated blood into distinct types, they could use that information to safely perform blood transfusions. Furthermore, forensic scientists could use that information to exculpate people suspected of some types of crimes, and they could use it to help determine the paternity of children.

Light therapy, also called phototherapy, exposes infants with jaundice, a yellowing of the skin and eyes, to artificial or natural light to break down the buildup of bilirubin pigment in the blood. Bilirubin is an orange to red pigment produced when red blood cells break down, which causes infants to turn into a yellowish color. Small amounts of bilirubin in the blood are normal, but when there is an accumulation of excess bilirubin pigment, the body deposits the excess bilirubin in the layer of fat beneath the skin. That accumulation of bilirubin causes the skin and the white areas of the eye to appear yellowed, a common symptom of jaundice. Buildup of bilirubin typically occurs when the immature liver of a newborn infant is unable to efficiently breakdown the bilirubin molecule into products that the body can excrete. High levels of bilirubin, a phenomenon called hyperbilirubinemia can be toxic and can lead to a brain dysfunction called kernicterus, which may result in permanent brain damage. The relative simplicity of phototherapy treatment has made effective neonatal jaundice treatment nearly universal, almost completely eliminating the risk of infant brain damage from hyperbilirubinemia.

The Mustard Operation is a surgical technique to correct a heart condition called the transposition of the great arteries (TGA). TGA is a birth defect in which the placement of the two arteries, the pulmonary artery, which supplies deoxygenated blood to the lungs, and the aorta, which takes oxygenated blood to the body are switched. William Thornton Mustard developed the operation later named for him and in 1963 operated on an infant with TGA, and ameliorated the condition, at the Hospital for Sick Children in Toronto, Canada. Afterwards, the Mustard Operation became the primary form of corrective surgery for TGA, until the arterial switch operation largely replaced the Mustard Operation by the late 1990s. The Mustard Operation enabled surgeons to correct TGA in infants born with the life-threatening anomaly, increasing their life spans and quality of life.

Scientists use cerebral organoids, which are artificially produced miniature organs that represent embryonic or fetal brains and have many properties similar to them, to help them study developmental disorders like microcephaly. In human embryos, cerebral tissue in the form of neuroectoderm appears within the first nine weeks of human development, and it gives rise to the brain and spinal cord. In the twenty-first century, Juergen Knoblich and Madeleine Lancaster at the Institute of Molecular Biotechnology in Vienna, Austria, grew cerebral organoids from pluripotent stem cells as a model to study developmental disorders in embryonic and fetal brains. One such disorder is microcephaly, a condition in which brain size and the number of neurons in the brain are abnormally small. Scientists use cerebral organoids, which they've grown in labs, because they provide a manipulable model for studying how neural cells migrate during development, the timing of neural development, and how genetic errors can result in developmental disorders.

In 1973, Ronald Ericsson developed the Ericsson method, which is a technique used to separate human male sperm cells by their genetic material. Ericsson, a physician and reproduction researcher, developed the method while conducting research on sperm isolation in Berlin, Germany, in the early 1970s. He found that the sperm cells that carry male-producing Y chromosomes move through liquid faster than the cells that carry female-producing X chromosomes. As a result of his findings, Ericsson suggested suspending a semen sample in a viscous liquid made from albumin protein, and collecting only sperm that quickly pass through the liquid. Shortly after Ericsson described his method, researchers demonstrated that it was effective for sex selection. However, later studies contested those results. Despite that, the Ericsson method is still utilized by couples in 2018 as a means of sex selection and was the first sperm separation technique used in combination with artificial insemination to enable people to select the sex of their children.