In 1983, researchers Alan Trounson and Linda Mohr published the article “Human Pregnancy Following Cryopreservation, Thawing and Transfer of an Eight-Cell Embryo,” hereafter “Human Pregnancy,” in the journal Nature. In the article, the authors describe an experiment that led to one of the world’s first pregnancies through cryopreservation, or freezing, of an eight-cell human embryo. They discuss an experiment conducted at the Monash University and Queen Victoria Medical Center in Melbourne, Australia. Prior to the article’s publication, scientists had reported on embryonic cryopreservation experiments with animals only. At the end of the article, the authors mention that the pregnancy ended in a spontaneous miscarriage due to problems unrelated to cryopreservation twenty-four weeks after embryonic transfer. Despite the miscarriage, “Human Pregnancy” is one of the first articles to describe a successful human pregnancy after cryopreservation, and demonstrated that cryopreservation, as part of in vitro fertilization treatment, was a viable option for humans as well.
In 1959, Charles Edmund Ford and colleagues published “A Sex Chromosome Anomaly in a Case of Gonadal Dysgenesis (Turner’s Syndrome),” hereafter “A Sex Chromosome Anomaly,” in The Lancet. Turner syndrome is a chromosomal disorder that affects one in 2,000 female births and results in developmental issues such as short stature, infertility, and congenital heart disease. Prior to “A Sex Chromosome Anomaly,” researchers did not know the cause of Turner syndrome, but Ford and colleagues found that the cause is a sex chromosome irregularity. In the article, the team explains that they examined the cells of a person with Turner syndrome and determined that she had just one X chromosome instead of the typical two. Thus, they concluded that the cause of Turner syndrome is a missing X chromosome and called for a new classification of the condition. “A Sex Chromosome Anomaly” was one of the first papers to identify the cause of Turner syndrome, and it provided scientists with a better understanding of individuals with a nontypical sex chromosome pattern.
In December of 2016, Margus Punab and colleagues published “Causes of Male Infertility: A 9-year Prospective Monocentre Study on 1737 Patients with Reduced Total Sperm Counts,” hereafter “Male Infertility,” in the journal Human Reproduction. The study examines the main causes of severe male factor infertility, or SMF infertility, which occurs when a male’s semen has a very low number of healthy sperm cells or contains atypically low levels of sperm cells. In “Male Infertility,” the authors determine the primary cause of SMF infertility in forty percent of their participants, and among those participants, they found that the primary causes of SMF infertility were varicoceles, or enlarged veins within the loose bag of skin holding the testicles. The authors did not determine the cause of SMF infertility in the remaining sixty percent of the cases, noting a gap in the current understanding of the causes of SMF infertility. “Male Infertility” was one of the first large-scale studies to reveal certain underlying causes of SMF infertility, and its conclusions have allowed researchers to investigate fertility solutions for male patients who would otherwise not be able to reproduce.