Androgens are a group of hormones that regulate male traits, including primary sex organs, and the development of secondary sex characteristics at puberty, such as facial and body hair growth or voice changes. Androgens also facilitate the communication between cells around the entire body, and play an important role in sexual health, as well as prenatal and pubertal development in...
An andrologist is a physician that specializes in male health, with a particular focus on the male reproductive system and sperm health as well as urological and sexual health issues, such as erectile dysfunction, prostate disease and male hormone deficiency. What is an andrologist? An andrologist is a type of urologist physician that specializes in […]
Andropause (also known as “male meno”) is characterized by a number of symptoms, including decreased libido, fatigue, androgen deficiency, and a gradual decline in male testosterone levels as they age. Andropause typically occurs in middle-aged to older people, and can trigger depression, a loss of sex drive, and erectile dysfunction.
Antisperm antibodies are immunoglobulins (immune system proteins) that are directed against sperm. This occurs when the immune system mistakenly identifies sperm as an invader and targets it, affecting fertility. While these antibodies are rare, they can be found in the semen, blood, or vaginal fluid. The production of these antibodies can be triggered in males […]
Artificial insemination is a fertility treatment that introduces sperm into a female's uteris or cervix with the goal of achieving pregnancy through in-vivo (in the body) fertilization. Two approaches exist in artificial insemination: intrauterine insemination (IUI) and intracervical insemination (ICI).
Assisted reproductive technology (ART) refers to medical procedures to address infertility. According to the CDC, ART includes all fertility treatments in which eggs and embryos are handled (such as in vitro fertilization). However, many in the fertility field also consider intrauterine insemination (IUI) and medicated cycles to be ART.
Asthenozoospermia (also known as asthenospermia) is an infertility condition in which a person has reduced sperm motility (the ability of the sperm to move). Reduced sperm motility decreases the chances of the sperm fertilizing the egg in the female reproductive tract. Asthenospermia is one of the most common causes of male-factor infertility, along with oligospermia (low sperm count).
Azoospermia is a medical condition where there is zero sperm in the male ejaculate. This condition can be obstructive or non-obstructive. While obstructive azoospermia refers to a blockage or disconnect that prevents sperm from entering the ejaculate, non-obstructive azoospermia refers to a condition that impairs sperm production in the testis.
Balanced translocation (also known as "chromosomal translocation") is a condition in which chromosomes are unusually rearranged. When balanced translocation occurs, a piece of the chromosome is broken off and attaches itself elsewhere. This can result in egg or sperm cells with missing or extraneous genetic material, possibly leading to fertility issues or miscarriage. What is […]
A biopsy is a medical procedure in which a sample of tissue is taken from the body to be analyzed in a lab. Many types of biopsies exist, including testicular, kidney, bone, and liver biopsies. Biopsies can be used to diagnose a medical condition, such as cancer, and to recommend a treatment method suited for […]
A blastocyst is a fertilized egg, or zygote, on day 5–6 after fertilization, when it typically has around 100 cells. A blastocyst can be characterized as a rapidly dividing ball of cells. A blastocyst is rated on a scale of one to six depending on its size, with a rating of 1 or 2 indicating it contains fewer cells. A...
A chromosome is a thread-like molecule of DNA that contains all of the genetic information of a particular organism. Chromosomes are made from proteins and a single molecule of deoxyribonucleic acid (DNA). This information contains specific instructions that will be passed on from parents to their children. What is a chromosome? A chromosome is a […]
Clinical pregnancy is a pregnancy that has been confirmed by both the presence of elevated levels of hCG (pregnancy hormone) and an ultrasound to visualize the gestational sac or heartbeat. Simply put, clinical pregnancy confirms there are clinical signs of the fetus that can be seen or heard. Typically, the earliest clinical signs can be detected five weeks into pregnancy.
Congenital absence of the vas deferens (CAVD) is a condition wherein the vas deferens, the duct that delivers sperm from the testicles to the urethra, does not develop properly prior to birth. There are two types of CAVD conditions: unilateral (CUAVD), or one side, or bilateral (CBAVD), or both sides. Those with CAVD are typically able to create sperm, but...
Cystic fibrosis is a progressive, genetic disease, causing lung infections and the persistent loss of lung functions. Most men with cystic fibrosis are infertile due to the absence of the sperm canal (also known as CAVD). As a result, those with cystic fibrosis may turn to assisted reproductive technology (ART) to have genetic children.
Donor insemination is a procedure where donor sperm is used to acheive pregnancy. This method typically refers to intrauterine insemination (IUI), but can also include intravaginal or intracervical insemination. Heterosexual couples may turn to donor insemination in cases where the male partner suffers from fertility issues, such as azoospermia or asthenospermia. This is also a common option for same-sex female...
An egg donor is a person that gives their eggs to a patient or couple that is experiencing difficulty conceiving. People who use egg donors may have low quality eggs or experience early menopause, or may be in a couple without a person with eggs. Egg donation is used as a part of IVF, with […]
Egg retrieval is one of a few steps completed during in vitro fertilization (IVF) or egg freezing. Once the ovarian follicles (containing eggs) have been identified and measured to ensure they are mature, the retrieval can take place. Using ultrasound guidance, a thin needle is inserted through the walls of the vagina to retrieve the eggs. The eggs are then...
Ejaculate is the semen released in one ejaculation (orgasm). The ejaculate contains sperm, and its quality can be evaluated through a semen analysis. Anything less than 15 million sperm per milliliter, or 39 million sperm per ejaculate, is considered low, which is also known as oligospermia. What is ejaculate? Ejaculate, also known as semen or […]
An embryo is an early stage development of a multicellular organism. Organs and crucial body structures are typically formed at this stage of human development. Before about the 10th day of gestation, the embryo is referred to as a blastocyst. The embryo is referred to as the fetus after the 11th week of pregnancy. What […]
An embryologist is a fertility scientist that helps create viable embryos in the lab using in vitro fertilization. Embryologists are tasked with managing eggs and sperm, creating embryos and monitoring them closely as they develop, and freezing eggs, sperm, and embryos. What is an embryologist? Embryologists are scientists who study the development of a fertilized […]
Endocrine disruptors, as the name suggests, are chemicals that interfere with the body's hormones. Endocrine-disrupting chemicals or EDCs are linked to reproductive, developmental, and brain problems along with cancer and metabolic disease. EDCs can be found in household products such as plastic bottles, detergents, and food. Endocrine disruptors have proven to be harmful to animals, but limited research exists to...
The epididymis is a coiled tube behind each testis. This reproductive organ is where the sperm are stored after being produced in the seminal vesicles. It's also where they undergo their final stage of maturation. The epididymis is linked directly to the ejaculatory duct by the vas deferens. What is the epididymis? Sperm are initially […]
Epididymitis is the inflammation of the epididymis, the tube located at the back of the testicles that is responsible for storing spem. Epididymitis-orchitis, by contrast, refers to the swelling of the testes and epididmis. This condition may affect people of all ages, but is prevalent between the ages of 14 and 35. Epididymitis and orchitis can be caused by bacterial...
Erectile dysfunction (ED), also referred to as "impotence," is characterized by the inability to sustain an erection long enough for sexual intercourse. Erectile dysfunction can be caused by a number of factors including cardiovascular disease, low testosterone levels, diabetes, stress, anxiety, and more.
The fertile window is the period during which a person can get pregnant. This window is the day an egg is released from the ovaries (ovulation) and the five days beforehand. This time period offers couples looking to conceive the best chance of getting pregnant naturally.
A fertility specialist is a medical professional that specializes in diagnosing and treating fertility issues in individuals experiencing difficulty trying to conceive. Typically, visiting a fertility specialist is recommended if you haven't been able to get or stay pregnant after 6–12 months of unprotected sex. What is a fertility specialist? Fertility specialists help couples or […]
Fertilization is the process in which an egg joins with a sperm. Typically, this takes place in the fallopian tube. If the fertilized egg successfully makes its way past the fallopian tube and into the uterus, it will hopefully implant into the uterine wall and begin developing as an embryo.
Follicle-stimulating hormone (FSH) is a gonadotropin, a hormone that acts on the gonads (the ovaries or testes). This hormone performs essential functions related to reproduction and pubertal development. FSH stimulates growth of the ovarian follicles and stimulates sperm production. What is follicle-stimulating hormone? Follicle-stimulating hormone (FSH) is a hormone involved in reproduction and the development […]
Gametes are an organism's reproductive cells and have also been referred to as "sex cells." Male gametes are called sperm; in females, they are called "ova" or egg cells. Gametes are haploid cells, which means that each cell carries one copy of each chromosome. These reproductive cells fuse with other haploid cells during fertilization in organisms that reproduce sexually (such...
A gene is a basic unit of heredity and is made up of a sequence of nucleotides in DNA or RNA. Genes carry information that determine traits, and are passed on from parents to their offspring. Every individual contains approximately 20,000 to 25,000 genes, including two copies of each gene, one from each parent. What […]
A gestational carrier, also known as a "gestational surrogate," is a person who carries and delivers a baby on behalf of a couple having difficulty getting pregnant. This approach can be used for hetero or LGBTQ couples who aren't able to carry a child on their own. Often, it will include in vitro fertilization (IVF) […]
Hormone replacement therapy refers to the use of supplemental hormones to treat low testosterone or post-menopausal symptoms, due to lower estrogen. HRT can treat the symptoms of hypogonadism. HRT is also used by transgender people, to help them develop physical characteristics that reflect their gender. This is usually called gender-affirming hormone therapy (GAHT). What is […]
Hormones are chemical messengers produced by the endocrine system that serve as chemical messengers throughout the body. Hormones regulate the body's processes, like hunger, reproduction, and sexual desire, by communicating with their target cell(s).
In-vitro fertilization (IVF) is a method of assisted reproduction, in which an egg is combined with sperm outside the body. Typically, during IVF, medication is used to stimulate the ovaries to produce multiple eggs. The eggs are removed directly from the ovaries before being combined with the sperm in a laboratory environment to fertilize. The […]
Infertility is defined as the inabiity to get or stay pregnant after 6–12 months of unprotected sex. Infertility is a "functional" diagnosis, meaning that it is based on the outcome — a lack of pregnancy — as opposed to specific lab tests. However, diagnostic testing can help provide an explanation for what is causing or contributing to infertility. Typically, male...
Intracytoplasmic sperm injection (ICSI) is an in vitro fertilization procedure typically used to address severe male-factor infertility, such as poor motility. During ICSI, a single sperm cell is injected directly into the cytoplasm of the egg to accomplish fertilization. Once fertilization occurs, the embryo typically grows in the laboratory for up to six days.
Intrauterine insemination (IUI) is a type of artificial insemination used to address infertility or use donor sperm. With this procedure, sperm is injected directly inside the uterus, helping it get closer to the egg to fertilize. Intrauterine insemination is done during ovulation to increase the chances of achieving pregnancy. What is intrauterine insemination (IUI)? Intrauterine […]
Kallmann syndrome is a genetic disorder that causes a condition known as hypogonadotropic hypogonadism (HH), in which very little sex hormones are produced. Kallmann syndrome is typically diagnosed at puberty due to a lack of sexual development, and affects fertility. Kallmann syndrome also causes an impaired sense of smell.
Kartagener's syndrome is a rare autosomal or "single gene" genetic disorder, and is a type of primary ciliary dyskenesia. In other words, the flagella and cilia — finger-like projections on the outside of cells — do not move as they should. This disorder is characterized by the mirror-image reversal of internal organs (situs invertus totalis) and can lead to neonatal...
A karyotype is a snapshot of an individual's chromosomes. In order to generate a karyotype, the chromosomes are isolated, stained, and examined under the microscope. This is done to determine the number of chromosomes and is also used to highlight any abnormalities. A karyotype can identify genetic disorders, such as Down syndrome. What is a […]
Klinefelter's syndrome (also known as "47 XXY") is a chromosal condition in which a biological male is born with an additional copy of an X chromosome. This condition typically leads to infertility as well as small and poorly functioning testicles. In many cases, however, Klinefelter's syndrome is extremely difficult to detect and may only be diagnosed deep into puberty or...
Luteinizing hormone (LH) is a hormone produced by cells in the anterior pituitary gland. Luteinizing hormone plays a crucial role in sexual development is also responsible for regulating key reproductive functions, such as controlling the menstrual cycle and triggering the release of an egg from the ovary. For people with sperm, LH regulates testosterone production. […]
Male-factor infertility refers to difficulty conceiving that's primarily due to the sperm's inability to fertilize the egg. Male-factor infertility can be caused by a number of factors, including low sperm production, chronic health problems, and abnormal sperm function. In cases of male-factor infertility, the female partner is typically ovulating normally and has healthy fallopian tubes. […]
A miscarriage is defined as the loss of a fetus before 20 weeks of pregnancy. Miscarriages typically occur in the first trimester of a pregnancy (prior to week 13). Miscarriages can happen for a variety of different reasons, ranging from genetic and chromosomal issues within the embryo to underlying conditions.
Morphology refers to the shape, size, and structure of sperm. Sperm morphology typically takes into consideration the head and tail of the sperm, as these can have a direct impact on the sperm's ability to reach and fertilize the egg. Abnormal sperm morphology can have an adverse effect on fertility and can be diagnosed in a semen analysis.
Sperm motility refers to sperm's ability to move or swim. It's an essential component in male fertility. Good motility is defined as sperm with forward progressions of at least 25 micrometers per second. Reduced sperm motility has an impact on fertility as sperm needs the ability to move through the female reproductive tract to reach and fertilize the egg. Those...
Oligospermia is the medical term for low sperm count. "Ligo" is the Greek term for little. Oligospermia refers to having less than 15 million sperm per milliliter of semen. Those with oligospermia have a reduced chance of fertilizing an egg and getting pregnant naturally.
An oocyte is an immature egg, the female gametocyte or germ cell involved in reproduction. Oocytes are produced in the ovaries during female gametogenesis.The oocyte matures and divides during the follicular phase and then again during ovulation, and becoming a mature ovum or egg.
Ovulation is the process in which a mature egg is released from the ovary. Ovulation is driven by a complex series of reproductive hormones and processes. A person is most fertile in the days leading up to ovulation, known as the "fertile window." Ovulation typically occurs halfway through the menstrual cycle, but the exact date depends on the length of...
A post-thaw analysis is a test in which a small portion of your pre-analyzed sperm sample is frozen, thawed, and reanalyzed, to assess how well it will survive cryopreservation. Post-thaw analysis gives the best estimate of how many motile sperm you’ll have when using your frozen sperm sample in the future.
Preimplantation genetic testing (PGT) examines embryos created using in vitro fertilization (IVF). PGT is used to diagnose genetically abnormal embryos or embryos that carry specific genes related to disease, before they are transferred into the patient's uterus. PGT helps avoid genetic defects at birth, miscarriage, and implantation failure and has since become an integral part of assisted reproductive technology.
Progesterone is a steroid hormone released in the ovaries, and is necessary for the implantation of the fertilized egg in the uterus and maintaining pregnancy. Progesterone is also used to regulate abnormal menstrual cycles and helps kickstart menstrual cycles that have abruptly stopped (known as amenorrhea).
Prostaglandins are a group of lipids that function similarly to hormones and manage processes including inflammation and blood flow. They are created during a chemical reaction at the site of an injury, and produce contractions during labor. Prostaglandins also play a role in maintaining erections.
Recurrent Pregnancy Loss (also known as "recurrent miscarriage" or "habitual abortion") is defined as three consecutive pregnancy losses prior to 20 weeks from the last menstrual cycle. Recurrent Pregnancy Loss can be caused by genetic or chromosomal issues as well as structural problems of the uterus.
A reproductive endocrinologist is a medical specialist in reproductive endocrinology and infertility (REI). A reproductive endocrinologist is an OB/GYN with advanced training in hormones, the science of fertility and the mechanics of conception, including sperm, eggs, male and female anatomy, and the relationship between pituitary and reproductive hormones.
Retrograde ejaculation is when semen flows back into the bladder, instead of emerging through the penis, during an orgasm. Therefore, very little semen will come out despite climax (hence why it's sometimes referred to as a "dry orgasm"). Retrograde ejaculation can have an adverse effect on fertility as sperm does not make its way into the partner's reproductive system.
The scrotum is the sac of skin located beneath the penis that holds and protects the testicles. The testicles are responsible for producing sperm, which happens most optimally at about 93.2ºF (5ºF cooler than the rest of the body). The scrotum moves closer to and further from the body, depending on environmental factors, to maintain that temperature. Scrotal tissues also...
Secondary infertility refers to the inability to get pregnant after previously giving birth to one or more children. This condition shares many similarities with primary infertility, including possible causes: impaired sperm production, ovulation disorders, endemetriosis, and uterine conditions.
Semen (also known as "ejaculate") is the thick, usually white fluid that emerges from the penis during ejaculation. Semen contains sperm, as well as substances that protect and nourish sperm on their journey. Semen is responsible for carrying sperm outside the male body and into the female reproductive system, in order to fertilize the egg and create an embryo.
Semen analysis (also known as "sperm count test" or "male fertility test") is an evaluation of a person's sperm and semen. This test determines the quality and the quantity of sperm, including key factors that will play a direct role in the fertilization of the egg such as motility (movement), concentration (density), and morphology (size and shape).
Semen volume is defined as the amount of semen, the fluid that contains sperm, produced during one ejaculation. According to the World Health Organization (WHO), semen volume can range anywhere between 0.8 millimeters to 7.6 millimeters. The average is 1–5 millimeters. Semen volume affects sperm concentration, and volume that's abnormally low may affect fertility.
Seminal vesicles (also known as the vesicular or seminal glands) are a pair of glands located in the male's pelvis, between the bladder and rectum. These vesicles are responsible for producing around 60% of the fluid that eventually becomes semen. The remaining fluid is created by the prostate and bulbourethral glands.
Seminiferous tubules are the tubes located within the testes where most of spermatogenesis, sperm production and maturation, takes place. Here, germ cells develop into spermatozoa by interacting with Sertoli cells. The seminiferous tubules are the site of the meiosis, or cell devision, which kicks off the creation of male gametes.
Sexually transmitted infections (STIs) are infections that can be passed from partner to partner during sexual activity. STIs are caused by an organism, such as a bacteria, a virus, or a parasite, and are most likely to be transmitted through unprotected oral, vaginal, or anal sex. In some cases, STIs can be passed on through skin-to-skin contact.
Ultrasound is a tool that uses sound waves to create a picture of something going on inside the body. Sonogram, on the other hand, is the picture an ultrasound generates. Ultrasound can be used to assess health or identify causes of pain or swelling in many parts of the body, including the testicles, and to examine a fetus inside the...
Sperm is the male reproductive cell or gamete, which carry half the genetic material for a person's offspring. The egg carries the other half; when combined, during fertilization, they make a unique genetic sequence. Sperm cells are produced in the seminiferous tubules of the testes in a process known as spermatogenesis.
A sperm bank (also known as "semen bank" or "cryobank") is a facility which preserves, stores, and may buy and sell sperm samples. Couples who trying to conceive may purchase donor semen from a sperm bank to use during artificial insemination. People that sell their semen to a sperm bank are known as sperm donors. Some people may also choose...
Sperm concentration, also known as sperm density, is defined as the number of sperm per milliliter of semen. Sperm concentration is one of the most important factors affecting male fertility; normal sperm concentration is over range from 15 million sperm per mL. A semen analysis can be used to measure sperm concentration. What is sperm […]
Sperm count refers to the total number of sperm in the entire ejaculate or semen sample. According to the World Health Organization (WHO), sperm count should fall anywhere between 39 to 928 million per ejaculation. This directly impacts fertility, as people with a lower sperm count are more likely to have trouble conceiving.
Sperm DNA fragmentation refers to the degree of abnormal genetic material (DNA) within sperm. High levels of damaged or degraded sperm DNA can contribute to male infertility, IVF failure, and miscarriage. Sperm DNA fragmentation can be caused by a number of factors including illness, injury, and lifestyle choices that cause oxidative stress.
Spermicide is a contraceptive substance that stops sperm from moving and/or kills it. This substance is typically inserted into the vagina before penetrative sex, ensuring that sperm will not make its way into the uterus for potential pregnancy. Spermicide can be used alone orin combination with other birth control methods (like condoms).
Teratospermia (also known as "teratozoospermia") is a condition characterized by abnormal sperm morphology — meaning that many of a person's sperm are the incorrect size, shape, or structure. Abnormalities could include a defect in the head, midpiece, or tail of the sperm. Teratospermia may have an adverse effect on fertilization, and can be related to genetic traits, chronic diseases, alcohol...
The testicles (also known as the "testes") are two small organs found inside the scrotum, part of the male reproductive system. The testicles are responsible for a number of essential functions, including the production of sperm and testosterone. Each testicle consists of a series of small tubes that are responsible for producing and storing sperm until it matures.
Testicular biopsy is a surgery done to remove a piece of tissue from the testicles. This tissue is then analyzed in a laboratory and can be used to diagnose the condition of a lump in the testes, identify causes of infertility, or obtain sperm for in vitro fertilization (IVF).
Testicular sperm aspiration (TESA) is a sperm retrieval procedure in which a doctor uses a needle to retrieve sperm directly from the testicular tissue. TESA is a procedure used prior to in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). TESA may be done for patients who have azoospermia, or no sperm present in the semen.
Testicular sperm extraction (TESE) is a sperm retrieval procedure that involves a doctor making a small incision in the testes with a scalpel, and examining the seminiferous tubules and testicular tissues for the presence of sperm. This procedure is typically done to diagnose the cause of azoospermia, or no sperm in the semen, or to freeze sperm for future fertility...
Testosterone is a sex hormone. It plays an integral role in developing "male" physical characteristics, as well as sex drive, fertility, and sperm production. Testosterone levels may also impact bone and muscle mass and red blood cell production. Typically, testosterone levels are highest just after puberty and decline with age.
Testosterone replacement therapy is a hormone therapy used to address abnormally low levels of testosterone. Low testosterone is also called hypogonadism. There are many forms of TRT available, including transdermal (skin patch), gels, mouth patches, and injections or implants. The goal of testosterone replacement therapies is to restore blood concentration levels of testosterone and improve symptoms of low T, such...
Trying to conceive (TTC) is a term commonly used to describe couples or individuals actively attempting to get pregnant. "TTC" often refers to the entire journey involved with achieving pregnancy, in addition to the act of unprotected sexual intercourse itself. This can include tracking menstrual cycles and ovulation, testing sperm quality, researching diets, and fertility treatments.
Undescended testicle(s) (also known as "cryptorchidism") is when one or more of a male baby's testicles has not yet moved into its proper position in the scrotum before birth. Testicles typically descend into the scrotum between weeks 32 to 36 into pregnancy. Premature babies are more likely to be affected by cryptorchidism. The undescended testicle should return to the scrotum...
Unexplained or idiopathic infertility is a condition defined by a lack of obvious cause behind a couple's or individual's infertility. Unexplained infertility can only be diagnosed after both partners have been completely evaluated with common fertility issues being ruled out. Unexplained infertility accounts for about 15–30% of all infertility cases.
The urethra is a narrow, muscular tube that is responsible for urine — and, in males, semen — from the bladder or ejaculatory ducts to the exterior of the body. The urethra is made up of a series of tissues, including prostatic, membranous, and spongy heterogenous segments. The urethra begins at the bladder and extends […]
A urologist is a medical professional that diagnoses and treats conditions relating to the urinary tract in both males and females. In males, urologists typically treat disorders to the prostate and reproductive system, including male-factor infertility, while in females, urologist offer treatment on conditions affecting the kidneys, the ureter, the urethra, and the bladder.
Varicocele is a medical condition in which the veins within the scrotum become enlarged. Approximately 15% of people with testes will experience a varicocele, but it doesn't always affect fertility. In some cases, the inflammation and increased heat caused by varicocele can lead to decreased sperm quality and low sperm production. This condition can lead to an inflamed testicle, typically...
The vas deferens is the set of tubes that's responsible for transporting sperm cells from the epididymis, where sperm is matured and stored, to the ejaculatory duct, so it can exit the body. This is the tube that's cut during a vasectomy, as a form of birth control. Each tube is about 11–17 inches long.
A vasectomy is a medical procedure to prevent pregnancy. During a vasectomy, the vasa deferentia (or vas deferens, the tubes that carry sperm from the testicles to the penis) are cut and tied to block sperm from getting into the semen. Vasectomy reversal surgery can undo a vasectomy, reconnecting each tube, but reversals are not guaranteed to be successful and...
Sperm viability is defined as the percentage of live sperm found in a semen sample. Viability is a crucial factor in fertility, as a high number of dead or non-moving sperm with lower the chance of natural conception. Sperm viability is a metric that can be measured through a semen analysis.
Vitrification is the process of flash-freezing a cell, such as an egg. Vitrification uses liquid nitrogen to quickly cool cells to -196ºC (at a cooling rate of 15,000°C/min). This speed ensures that water molecules inside the cell don't have time to form potentially damaging ice crystals, making it the more effective method for freezing eggs, which have a high proportion...
The X-chromosome is one of the two sex chromosomes, used to determine genotypical sex. Your X chromosome comes from your mother's egg. Typically, females have two X (XX) chromosomes, while males usually have an XY pairing. Some people may have atypical chromosome combinations, such as XXY, also known as Klinefelter syndrome.
The Y-chromosome is one of the two sex chromosomes, used to determine genotypic sex. Typically, females have two X (XX) chromosomes, while males usually have an XY pairing. Sperm may carry an X or Y chromosome. The Y-chromosome is contains the gene SRY, which triggers male development and is responsible for sperm production.
Y-chromosome microdeletions (YCM) is a family of genetic disorders caused by missing genes in the Y-chromosome, and are common in infertile men. This condition directly affects sperm production and can lead to conditions such as oligospermia, azoospermia, and teratospermia.