Ch.15 human repro.pdf

CHAPTER 15 Infertility Infertility Defined as the inability to become pregnant after a year of unprotected coitus. In Canada rates of infertility are estimated at 11.5-15.7%. When looking at causes of infertility, approximately 35% of cases are related to the egg donor, 35% of cases are related to...

CHAPTER 15 Infertility Infertility Defined as the inability to become pregnant after a year of unprotected coitus. In Canada rates of infertility are estimated at 11.5-15.7%. When looking at causes of infertility, approximately 35% of cases are related to the egg donor, 35% of cases are related to the sperm donor, 20% of cases are problems with both donors/incompatibility, and 10% are unknown. Determining the Cause In order to treat the infertility, it is imperative to understand what is causing the problem(s). For all individuals a physical and medical history are taken. For the egg donor: menstrual cycle tracking, hormone panel through blood work, imaging to assess tubal/uterine obstruction, endometrial biopsy, and a Huhner’s test may be analyzed. For the sperm donor: collection and examination of sperm (count, volume, motility, structure), hormone panel through blood work, testicular biopsy, and immunological tests (antibodies against their own sperm) may be analyzed. Infertility in the Egg Donor Age plays a major role in egg donor infertility. Individual’s over the age of 35 may be considered infertile if pregnancy does not occur within 6 months. Common causes: failure to ovulate, tubal blockage, implantation issues, problems with sperm transport/immune response, miscarriage. Human Reproductive Biology, 4th Ed. (2014) pg. 287 Failure to Ovulate When an individual is failing to regularly menstruate, their ovulation rates diminish and may be difficult to predict. Can be related to hormonal issues (brain/gonads), over exercising, stress, and weight gain. Can be treated with GnRH, clomiphene, gonadotropins, or human menopausal gonadotropin (hMG) + hCG to induce ovulation. Human Reproductive Biology, 4th Ed. (2014) pg. 286 In individuals with high levels of prolactin, bromocriptine can be administered. Tubal Blockage This is the second leading cause of infertility in egg donors. Occurs when a physical obstruction prevents the meeting of sperm and egg. https://veritasfertility.com/conditions/tubal-blockage/ May be linked to previous STIs (chlamydia), pelvic inflammatory disease, or endometriosis. May be treated with surgery or methods to expand the blocked tube (fluid/gas, transcerivcal balloon tuboplasty). Absence of Implantation Reduced Sperm Transport/Hostile Environment An embryo may form, but implantation does not occur. The vaginal canal and cervix are naturally inhospitable to sperm. However, an individual’s internal environment may be more acidic and damaging than normal. Often due to lack of steroid hormones. May also be related to scar tissue/fibroids blocking access to appropriate endometrial tissues. An individual may also produce antibodies against the sperm, which then doesn’t reach the egg. Pregnancy Loss Miscarriage is the most common disorder of pregnancy. An individual may be infertile because they are unable to sustain a pregnancy and experience multiple miscarriages. May be related to physical/genetic make up of carrier, chromosomal abnormalities, exposure to mutagenic/teratogenic compounds or immunological rejection of the embryo. Human Reproductive Biology, 4th Ed. (2014) pg. 288 Infertility in Sperm Donor Infertility of the sperm donor is generally related to the individuals ability to produce enough high-quality sperm. Issues with producing high quality sperm may be related to hormone imbalance or a physical/structural abnormality. Exposure to toxic chemicals can also alter sperm quality/quantity. Human Reproductive Biology, 4th Ed. (2014) pg. 289 Low Sperm Count Low sperm count is the leading cause of sperm donor infertility. May be a low number (oligospermia) or absence of sperm (azoospermia). Assessed through counting sperm from a diluted sample of semen. Quality of sperm motility and overall physical structure is also assessed. https://www.researchgate.net/publication/292208739_Automated_Analysis_of_Human_Sperm_Number_and_Concentration_Oligospermia_Usin g_Otsu_Threshold_Method_and_Labelling/figures?lo=1&utm_source=google&utm_medium=organic Sperm Transport Environmental Factors Sometimes the passage of sperm through the individual’s reproductive system is blocked. Contact with toxic and/or mutagenic compounds can reduce the quality/quantity of sperm. Can be due to swelling in surrounding tissues, previous infections, or improperly functioning sex accessory glands. Physical stress (increase in temperature or pressure) can also temporarily decrease sperm production. Gamete Storage and Artificial Insemination For individual’s who are dealing with infertility, assisted reproductive techniques (ARTs) may be used. Includes artificial insemination (AI). https://www.hopkinsmedicine.org/gynecology-obstetrics/specialtyareas/fertility-center/infertility-services/intrauterine-insemination AI may use sperm from a partner or a donor (sperm bank). Sperm can be stored in a deep freeze for up to 10 years. Egg retrieval and storage is also possible, however the process is not as common as it is most difficult to perform. In Vitro Fertilization In vitro fertilization (IVF) is the combination of egg and sperm outside the body, the production of a pre-embryo, and the insertion of the pre-embryo into a carrier. First performed in 1978 in Bristol, England. Required extensive research in order to move from the first fertilized human egg in 1944 to a fully implanted embryo. https://doctorhanna.com/our-services/in-vitro-fertilization-ivf/ Part 1. Ovarian Stimulation and Egg Retrieval Ovaries are stimulated to produce multiple follicles with FSH analogs. GnRH agonists/antagonists may be administered to control when ovulation occurs. Directly before retrieval, hCG is given to induce egg maturation and ovulation. Prior to ovulation, the ova of the mature follicles are suctioned out by a needled inserted through the vaginal wall. https://www.news-medical.net/health/Stages-of-IVF.aspx Part 2. Fertilization and Embryo Transfer Sperm are placed in a petri dish with media to nourish and prepare them for fertilization. The collected ova are mixed into this dish and fertilization occurs typically within 12-14 hours. Fertilized embryos are moved to another dish, and remain growing there for 3-5 days. The preembryos are then transferred into the carriers uterus. Implantation takes ~2 weeks. Over 2.5 million cycles of IVF are performed each year worldwide. https://www.news-medical.net/health/Stages-of-IVF.aspx Risks of IVF The biggest risk with IVF is failure. Most individuals who undergo IVF will need to do more than one cycle in order to maintain a successful pregnancy. As risk of improper implantation is high with IVF, often multiple embryos are inserted which increases the risk of multiples for each pregnancy. Emotional and physical stress, and high costs prevent many from utilizing IVF. https://newlifefertility.com/about-us/our-success-rates/ Preimplantation Genetic Diagnosis A single cell can be removed from a preembryo (only 8 cells) to determine genetic abnormalities. This is called an embryo biopsy. This process allows for the monitoring of the genetic makeup of in vitro grown embryos. This is termed preimplantation genetic diagnosis (PGD). Although PGD has decreased the risk of passing down fatal inherited diseases, it has also opened the possibility to screen for other non-threatening characteristics. Egg Donation When an individual is unable to use their own eggs, or they do not produced eggs, an egg donor may be used. Note: in this context egg donor means an egg sourced from an individual not involved in wanting the child. This is more complicated and costly than sperm donation. Works best is the eggs are retrieved from an individual in their 20s/30s. Individuals can successfully carry pregnancy from a donated egg far past the age of their own ages degrading. Gamete/Zygote Intrafallopian Transfer This technique is used for individuals who ovulate regularly, but have some structural barrier to zygote movement into the uterus. Similar to IVF, eggs are retrieved from the individual. Donor eggs may also be used. Eggs and sperm may be independently inserted into the uterine tube, or a zygote may be create in vitro and inserted. Success rates are similar to IVF, but technique is less common. https://www.surrogacycentregeorgia.com/art-assisted-reproductivetechnology/gamete-intrafallopian-transfergift/ Surrogates and Gestational Carriers Surrogates are individuals who are inseminated with another individual’s sperm/donor sperm, but do not want the pregnancy. This individual becomes pregnant, births the child, and then gives the child to the individual/couple who wanted the pregnancy. The surrogate is a biological parent. A gestational carrier is an individual who has the pre-embryo of another individual/couple inserted into their uterus and carries the pregnancy to term. The gestation carrier is not a biological parent. https://www.reddit.com/r/howyoudoin/comm ents/9ory12/which_real_life_incident_do_yo u_think_was_best/ Adoption Individuals or couples who are unable to conceive may decide to adopt. Adoptions may be closed, where little to not information is provided to the biological parent(s) of the adopted child, or open, where biological parents(s) may be a continuing presence in the life of the adopted child. Within Manitoba several different forms of adoption exist. The regulations surrounding approval of adoption are often dependent on what type of adoption is being performed.