In the twentieth century, researchers developed the oral glucose tolerance test, or OGTT, as a method to diagnose different types of diabetes, a medical condition that causes blood sugar levels to become abnormally high. During the test, a healthcare provider measures a person’s blood sugar levels before and after the person consumes a predetermined amount of glucose solution. While not exclusively used for pregnant women, an OGTT may test for gestational diabetes which, according to the International Diabetes Federation, affected one in six pregnancies worldwide in 2019. Generally, the results from an OGTT can inform a patient and her physician how her body is responding to glucose during pregnancy, and high levels may increase her risk of developing adverse pregnancy outcomes such as heavy bleeding during delivery and a high blood pressure condition known as preeclampsia. An OGTT can help to accurately diagnose, treat, and monitor gestational diabetes in pregnant women, which can reduce health and pregnancy complications for the woman and the fetus.

Transvaginal ultrasound-guided oocyte retrieval, also known as egg retrieval, is a surgical technique used by medical professionals to extract mature eggs directly from the women’s ovaries under the guidance of ultrasound imaging. In 1982, physicians Suzan Lenz and Jorgen Lauritsen at the University of Copenhagen in Copenhagen, Denmark, proposed the technology to improve the egg collection aspect of in vitro fertilization, or IVF. During IVF, a healthcare practitioner must remove mature eggs from a woman’s ovaries to fertilize them with sperm outside of the body. Transvaginal ultrasound-guided egg retrieval is a surgery that can be completed in a medical office setting in twenty minutes. Transvaginal ultrasound-guided egg retrieval increased mature egg collection and rates of successful fertilization, becoming the new standard for egg collection in IVF.

Researchers Geoffrey Sher and Jeffrey Fisch gave Viagra, also known as sildenafil, to women undergoing fertility treatment to test whether the medication could improve fertility and pregnancy rates. The researchers proposed that Viagra, typically indicated to treat erectile dysfunction in men, would help women with a history of failed past fertility treatments by thickening their endometrial lining, which is the layer of tissue in the uterus where an embryo implants during pregnancy. Sher and Fisch gave the women Viagra during in vitro fertilization, or IVF, an assisted reproductive technology. They summarized their findings in the article “Effect of Vaginal Sildenafil on the Outcome of In Vitro Fertilization (IVF) After Multiple IVF Failures Attributed to Poor Endometrial Development,” published in Fertility and Sterility in 2002. Although they noted additional research was needed, Sher and Fisch concluded that the prescribed combination treatment of Viagra and IVF resulted in an increased thickening of the endometrium lining which enabled the embryo to implant and result in a pregnancy.

In 2007, Ishola Agbaje, Deirdre Rogers, Carmel McVicar, Neil McClure, Albert Atkinson, Con Mallidis, and Sheena Lewis published “Insulin Dependent Diabetes Mellitus: Implications for Male Reproductive Function,” hereby “Diabetes Mellitus: Implications,” in the journal Human Reproduction. In their article, the authors explore the effects of elevated blood sugar in the form of diabetes mellitus on the quality of male sperm. When investigating possible fertility issues, fertility specialists often study semen, the male reproductive fluid that contains sperm cells to detect changes in sperm count, movement, and structure. In “Diabetes Mellitus: Implications,” the authors use both conventional semen analysis and technical molecular methods to assess the quality of sperm from diabetic and non-diabetic men. The authors found that men with diabetes had higher levels of DNA damage within their sperm and highlighted a need for additional research on the link between diabetes and male reproductive health.

Ovarian hyperstimulation syndrome, abbreviated OHSS, is an atypical reaction that women may experience in response to excessive hormones, and often occurs during fertility treatments. OHSS is typically triggered by hormonal medications designed to mature eggs in the ovaries, which can cause blood vessels within the ovaries to leak fluid. Sometimes that can lead to painful tenderness or swelling. In severe cases of OHSS, that fluid can leak into the abdominal cavity in large amounts, causing vomiting, blood clots, and severe pain. As many as one out of three women undergoing fertility treatment will experience some form of OHSS, although more severe presentations are rare. While the exact cause of OHSS is not fully understood as of 2020, researchers continue to discover various risk factors, prevention techniques, and treatments that may lead to decreased risks associated with OHSS and better fertility outcomes.

Gestational diabetes is a medical condition that causes blood sugar levels to become abnormally high, which manifests for the first-time during pregnancy and typically disappears immediately after birth for around ninety percent of affected women. While many women with the condition do not experience any noticeable symptoms, some may experience increased thirst and urination. Although gestational diabetes is treatable, if left unmanaged, the resulting fetus is more likely to have elevated risks of increased birth weight, birth injuries, low blood sugar, stillbirth, and later development of type 2 diabetes. The International Diabetes Federation estimates that worldwide in 2019, gestational diabetes affected one in six pregnant women, with many cases occurring in women living in low and middle-income countries. Despite the prevalence and risks associated with gestational diabetes, as of 2020, researchers have yet to reach a unified consensus on the best guidelines for diagnosis and treatment.

Orchiopexy, also known as orchidopexy, is a surgical technique that can correct cryptorchidism and was successfully performed for one of the first times in 1877 in Scotland. Cryptorchidism, a condition where one or both of the testicles fail to descend before birth, is one of the most common male genital birth defects, affecting approximately 2 to 8 percent of full-term male infants, and around 33 percent of premature infants. Typically in the womb, male testes form within the abdomen, then descend into the scrotal area between twenty-five to thirty-five weeks’ gestation. If one or both testicles fail to descend before birth, physicians use orchiopexy to surgically relocate the undescended testes to their normal position in the scrotum. According to many researchers, most cases of cryptorchidism do not resolve on their own, and therefore, orchiopexy surgery is often necessary. Orchiopexy, when performed before puberty, can decrease the risk of testicular cancer and infertility associated with cryptorchidism.

First manufactured in 1988 by Serono laboratories, recombinant gonadotropins are synthetic hormones that can stimulate egg production in women for use in fertility treatments. Recombinant gonadotropins are artificially created using recombinant DNA technology, a technology that joins together DNA from different organisms. In vertebrates, naturally-occurring gonadotropins regulate the growth and function of the gonads, known as testes in males and ovaries in females. Medical professionals can derive female gonadotropins from the urine of pregnant and post-menopausal women, often using it to facilitate in vitro fertilization, or IVF. With the rapid development of assisted reproductive technologies like IVF, demand for human-derived gonadotropins rose to a global yearly demand of 120 million liters of urine by the beginning of the twenty-first century, which resulted in a demand that could not be met by traditional technologies at that time. Therefore, researchers created recombinant gonadotropins to establish a safer and more consistent method of human gonadotropin collection that met the high demand for its use in fertility treatments.