IVF glossary

Sometimes a semen analysis reveals that there are no sperm in the ejaculate; this is a condition called azoospermia. This absence is most often due to primary testicular failure, a lack of germ cells, blockage of the ducts or previous vasectomy.

A semen analysis can reveal asthenospermia, i.e. a condition where the sperm are not vital or motile enough to reach the egg and fertilise it. Asthenospermia is usually one of the reasons why a couple is unable to conceive a baby.

Assisted hatching involves breaking the hard shell of the embryo, which facilitates its implantation and thus increases the success rate of artificial insemination. Assisted hatching is recommended for women after repeated unsuccessful attempts at embryo implantation, for older women and for frozen embryo transfers (FET).

Assisted hatching consists of disrupting the hard shell of the embryo. This facilitates implantation (nesting) and thus increases the success of IVF. We recommend assisted hatching for women who have had repeated unsuccessful embryo implantation attempts, for older women, and for the transfer of frozen embryos (CET).

Small follices in the ovaries containing immature eggs. The antral follicle count is used as an indicator of ovarian reserve.

During a normal menstrual cycle, the egg matures and is released into the uterus, but this is not the case in anovulation - making it impossible for the woman to become pregnant. There are many causes of anovulation, but the most common ones include an unhealthy lifestyle, hormonal imbalance, malnutrition/excess weight, thyroid disorders, polycystic ovary syndrome, or advanced age. It is quite natural for women to not ovulate in about 25% of menstrual cycles.

One possible result of a genetic test is aneuploidy, which is a defect in the number of chromosomes occurring during conception. One possibility is trisomy, in which three copies of a chromosome are formed during conception. This means the individual has 47 chromosomes instead of 46. The risk of this occurring increases with the mother's age, whereas it most often affects chromosomes number 21 (Down syndrome), 13 (Patau syndrome) and 18 (Edwards syndrome).

Amniocentesis, or amniotic fluid sampling, is the most common invasive method used for prenatal diagnosis. Guided by ultrasound, about 20 ml of amniotic fluid is collected using a very fine needle at between the 16^th and 20^th week of pregnancy. Testing amniotic fluid can reveal certain serious congenital disorders (such as Down syndrome).

AMH (Anti-Müllerian Hormone) in the female body controls the process of egg maturation. The number of eggs a woman has left can be estimated based on the amount of AMH in the blood. The amount of AMH in the blood decreases with age. A simple blood test is used to determine the amount, and this can be done at the clinic.

We recommend the ALICE test for women who have had repeated unsuccessful embryo transfers. The ALICE test is used to detect chronic inflammation. To do this, a small sample of the endometrium (uterine lining) must be taken. This one sample can also be used to perform an EMMA and ERA test at the same time.

The 5th to 6th day of an embryo's development after fertilisation; blastocysts have a higher chance of successful implantation in the uterus. The blastocyst stage is an early embryonic stage of a human foetus, consisting of approximately 120 cells. In IVF, the embryo is transferred to the woman's uterus at this stage. The remaining blastocysts can be frozen for further attempts.

A biochemical pregnancy refers to a condition in which a woman has a positive urine or blood pregnancy test but miscarries before the pregnancy is confirmed by ultrasound. In this case, the miscarriage occurs within the first two weeks following embryo implantation. The usual cause of this miscarriage is a genetic defect in embryo development.

This is an error in the genetic code that is caused by the breaking off and reattaching of different chromosomes. A balanced translocation carrier is completely healthy, but his sex cells (eggs or sperm) contain defective chromosomes with missing or redundant genetic information. For this reason, there is a higher probability that this 'carrier' will have a child with some degree of disability or that the pregnancy will end in miscarriage. Genetic testing can determine whether a person has balanced translocation or not.

An IVF cycle in which a woman uses eggs from an anonymous donor; this is recommended for women with a low ovarian reserve or genetic problems.

The process of freezing eggs, sperm or embryos for future use; the modern vitrification method ensures a high chance of cell survival after thawing.

When a pregnancy is already clearly visible on the ultrasound, or the 'cardiac activity of the embryo' can be heard, then it is considered a clinical pregnancy. It can usually be detected from week 5-6 of pregnancy.

The drug Estrofem contains the female hormone oestrogen, which is used in assisted reproduction methods to support the growth of the endometrium.

A genetic test that determines when the endometrium is best prepared for embryo implantation; the results allow for more precise timing of an embryo transfer.

The lining of the uterus that prepares to receive a fertilised egg; the quality of the endometrium is crucial for successful implantation of an embryo.

Endometriosis is when tissue similar to the uterine lining (endometrium) in the uterine cavity appears in an abnormal location - most often in the genital organs outside the uterus, but also in the intestines, urinary system and lungs. This often very painful disease can cause women of childbearing age to have problems conceiving. It is treated hormonally or surgically, or with a combination of both methods. However, treatment is often unsuccessful.

"Endometriosis is when tissue similar to the uterine lining (endometrium) in the uterine cavity appears in an abnormal location — most often in the genital organs outside the uterus, but also in the intestines, urinary system and lungs. This often very painful disease can cause women of childbearing age to have problems conceiving. It is treated hormonally or surgically, or with a combination of both methods. However, treatment is often unsuccessful."

The thickness and structure of the endometrium, which is crucial for successful embryo implantation, is assessed. The optimal thickness of the endometrium is 7-12 mm.

The uterine lining that prepares to receive a fertilised egg; its thickness and structure are decisive for successful implantation.

An EMMA test analyses the microbial composition of the uterine lining (endometrium). It detects any microbial imbalances that may affect the success of embryo implantation and pregnancy. This test helps identify problems, such as a lack of beneficial lactobacilli, and it is used to establish appropriate treatment, such as probiotics or antibiotics, to optimise the environment for embryo attachment.

This is an advanced incubator that allows time-lapse monitoring of embryo development. It helps embryologists select the best embryo for transfer. EmbryoScope allows continuous monitoring of embryo development 24 hours a day; this enables the selection of the best embryos for transfer, thereby increasing the success rate of assisted reproduction. Another advantage is that the microscope is located directly in the incubator, so the embryos do not need to be moved for monitoring.

The heart of the IVF clinic, where egg fertilisation, embryo cultivation, genetic testing and preparation for transfer take place; state-of-the-art technology and an experienced team of embryologists are crucial for treatment success.

EmbryoGlue helps embryos implant in the uterine wall, thereby increasing the success rate of IVF. EmbryoGlue is a tissue adhesive that mimics the environment in the uterus during natural embryo implantation.

EmbryoGen is a culture medium that helps create an environment similar to the natural environment in a woman's body following in vitro fertilisation. As a result, the chances of attachment and successful growth of the embryo are increased following its transfer to the woman's uterus.

An embryo transfer (ET) is the final stage of an IVF cycle, when the selected embryo is transferred to the patient's uterus. The process is painless and is usually performed under ultrasound guidance. An embryo transfer is the transfer of an embryo into the uterine cavity. The transfer is painless and takes about 5 minutes; it is performed while the patient is fully conscious. A thin catheter is used to transfer the embryo, and the entire process is guided by ultrasound.

Embryos are evaluated based on cell count, symmetry and fragmentation. High-quality embryos have a higher chance of successful implantation.

Embryo implantation takes place on the 6^t to 7^th day after fertilisation. The goal is for the embryo to attach to the uterine lining. This process can be aided by additional methods such as assisted hatching or EmbryoGlue. After successful implantation, the hormone hCG starts being released into the blood, which allows confirmation of pregnancy.

The process in which embryos are kept in a laboratory after fertilisation; they are usually cultivated for 3–5 days, until the blastocyst stage.

This includes ejaculation disorders, such as retrograde ejaculation or premature ejaculation, which can affect fertility. IVF offers options to overcome these obstacles.

A fundamental factor in the success of fertilisation and embryo development; egg quality declines with a woman's age, especially after the age of 35.

A process in which a woman donates her eggs to another couple who cannot conceive with their own; this is often used when a woman has a low ovarian reserve or genetic problems.

The loss of a pregnancy within the first 12 weeks; this can occur due to genetic, anatomical or immunological factors.

Follicle-stimulating hormone (follitropin) is a hormone that stimulates the activity and development of the sexual organs and further regulates the proper function of the reproductive organs. Follitropin has the specific task of stimulating the growth and maturation of the follicles in which the eggs are stored. Its levels are therefore high until the fertile days, dropping after ovulation and remaining at very low levels until the next cycle.

The process of thawing a frozen embryo and then transferring it into the uterus; this method allows the use of embryos from previous IVF cycles.

This is an ultrasound examination in which a probe inserted into the vagina evaluates the condition of the follicles in the ovaries. It is not performed once, but repeatedly, in order to monitor the dynamics of follicle growth and predict the date of ovulation. It is recommended as one of the first basic examinations for women who are unable to conceive.

In follicular puncture, eggs are collected from the ovaries under general anaesthesia for subsequent fertilisation in the laboratory or freezing. This retrieval is performed with a thin needle under ultrasound guidance and takes no more than 15 minutes.

The Follicular phase is the first half of the menstrual cycle, respectively the phase before ovulation, during which a new egg or eggs are matured under the influence of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). In the first days of the follicular phase, the lining of the uterus is the thinnest, but it thickens as ovulation approaches. Towards the end of the phase, luteinizing hormone (LH) also becomes active, helping follicular maturation and subsequent ovulation.

A follicle is a pouch filled with fluid that contains an egg (oocyte). After the follicle ruptures, it releases a mature egg. Each ovary contains approximately 1.5 million follicles at birth, but only about 400 reach maturity.

The ability of an egg and sperm to unite and form an embryo; it is assessed in the laboratory after fertilisation.

The ability of a woman or man to conceive a child naturally; factors affecting fertility include age, lifestyle and health.

Unlike men, women are only fertile a few days in a month - the probability of conception is highest during their fertile days, which are usually 3 days before and 1 day after ovulation.

Gonadotropins are hormones that are naturally produced by a part of the brain called the pituitary gland. This is an endocrine gland that stimulates the activity of the gonads by producing gonadotropins, and it is in charge of the secretion of sex hormones. In reproductive medicine, these hormones are administered in the form of stimulating drugs that stimulate the ovaries to produce more than one follicle.

Medications used in IVF to control ovulation. They prevent premature egg release, allowing doctors to time the retrieval.

Another group of drugs for regulating the menstrual cycle during IVF; they are mostly used in a long stimulation protocol.

GERT is a special test that determines when the uterine lining (endometrium) is most ready to receive an embryo. This moment, called the receptive window, is crucial for successful embryo implantation. The test helps optimise the timing of an embryo transfer and increases the chances of pregnancy.

Embryo screening to identify specific genetic mutations associated with serious monogenic diseases such as cystic fibrosis or Huntington's disease. This method helps couples with a genetic burden reduce the risk of passing on the inherited disease to their child. PGT-M allows us to select embryos without the given mutation, increasing the chance of having a healthy child.

A diagnostic or therapeutic method that allows examination of the uterine cavity with a special camera; it helps detect polyps, fibroids or other abnormalities.

A disorder in which the body does not produce enough sex hormones; it can affect fertility in both men and women, and it requires treatment with hormone replacement therapy.

Elevated levels of the hormone prolactin, which can disrupt ovulation and the menstrual cycle; this condition is treated with medications to lower prolactin levels.

The process of administering drugs to stimulate the ovaries to produce eggs; this allows for the retrieval of more eggs in a single cycle.

A set of blood tests that evaluate hormone levels such as FSH, LH, AMH, oestradiol and progesterone. The results help diagnose the causes of infertility.

An assisted reproduction method in which an egg is fertilised by sperm outside a woman's body in a laboratory; the embryo is then transferred to the uterus. IVF is suitable for various causes of infertility, such as blocked fallopian tubes or low sperm quality.

IUI (Intrauterine insemination) is the least invasive method of assisted reproduction. After preparing sperm in the laboratory, this is introduced into the uterus using a thin catheter.

The inability to conceive after one year of regular unprotected sex; this may be caused by male reproductive issues, female reproductive issues, or a combination of both.

The period of time during which the endometrium is best prepared to receive an embryo; this process is crucial for successful implantation. The implantation window is when the endometrium is most receptive, increasing the chance of embryo implantation in IVF.

A condition in which a woman's or man's immune system reacts negatively to sperm, eggs or embryos.

Tests that detect antibodies against sperm, eggs or embryos; these tests help identify possible obstacles to reproduction.

Eggs that have not reached full maturity and cannot be fertilised; in vitro maturation (IVM) can be used in IVF.

ICSI (intracytoplasmic sperm injection) is a method of introducing sperm directly into an egg using a thin needle. It serves to increase the probability of egg fertilisation. We use this method to fertilise most eggs.

A karyotype test is a basic genetic laboratory test conducted to exclude chromosomal aberrations in the number or shape of chromosomes. Genetic testing of women or couples plays an important role in the management of diagnosis of fertility disorders. We most often recommend this test for women who have had repeated miscarriages, for women in later reproductive age, and for couples who have given birth to a genetically or otherwise affected foetus. It is also an important test before the preimplantation genetic testing (PGT) plan of embryos.

A hormone that triggers ovulation and progesterone production; its levels are key to timing ovulation and egg retrieval.

The luteal phase begins after ovulation, when the 'yellow body' (corpus luteum) is formed from the Graafian follicle. The cells of this body produce a large amount of progesterone, which acts on the lining of the uterus and supports the implantation and retention of the fertilised egg - embryo. If fertilisation does not occur, then the corpus luteum disintegrates and a rapid drop in progesterone and other hormones triggers menstrual bleeding.

A minimally invasive surgical method used to diagnose and treat causes of infertility, such as endometriosis or fallopian tube adhesions.

A procedure where multiple embryos are transferred into the uterus to increase the chances of pregnancy. However, it carries the risk of multiple pregnancy. This approach is mostly chosen for older patients or after repeated unsuccessful IVF attempts. Modern clinics try to only transfer a single high-quality embryo (eSET) to reduce the risks associated with multiple pregnancy.

Advanced technology for selecting the highest quality sperm; it helps reduce the risk of genetic abnormalities and improves the chances of successful fertilisation.

MESA (Micro Epididymal Sperm Aspiration) is a surgical procedure that allows the retrieval of sperm in case of impaired transport of sperm between the epididymis and urethra. A microsurgical incision is made in the skin to insert a puncture needle and the fluid containing sperm is aspirated.

When a semen analysis shows normospermia, this means that all parameters of the ejaculate (sperm concentration, their overall motility or vitality, leukocytes) are within normal limits.

• Ejaculate volume greater than 1.5 ml
• The sperm count per ml of ejaculate is at least 15 million
• The ejaculate contains at least 40% motile sperm
• At least 4% of the sperm have a normal shape

An ovulation test is used to determine the days in a woman's cycle when she is most fertile and therefore has the highest chance of successful conception. These tests work similarly to pregnancy tests, and the most suitable time to perform them is around the 10th day of the cycle. You can buy them in any drugstore or pharmacy.

The drug Ovitrelle (in the form of a solution for injection) is used in women undergoing IVF and in women who are not ovulating (so-called anovulation), or who only ovulate in a small percentage of menstrual cycles (oligoovulation). In IVF, it helps mature the follicles; it is administered in patients who have problems with ovulation for the process of triggering the release of eggs (ovulation) - in both cases, however, it is used after women have taken other drugs for the development of follicles.

A process in which hormones are injected to stimulate the ovaries to produce multiple eggs in one cycle; this step is crucial to increase the chances of IVF success.

The ability of the ovaries to produce quality eggs; ovarian reserve testing includes measurement of AMH and FSH, and an ultrasound scan of antral follicle count.

A condition in which the ovaries stop producing eggs before natural menopause; IVF with donor eggs is one solution to this problem. This syndrome can be caused by genetic factors, autoimmune diseases, chemotherapy or other medical conditions. Symptoms include irregular periods, hot flashes, and low estrogen levels, which can also affect a woman's overall health. Diagnosis includes hormone tests and ovarian reserve testing, and treatment focuses on hormone replacement therapy and assisted reproduction options.

This is a potential complication of hormonal stimulation of the ovaries, in which the ovaries most often overreact to the administered drugs. Hyperstimulation syndrome is accompanied by pressure and pain in the lower abdomen, an enlarged abdomen, impaired urination or nausea and vomiting. These symptoms usually subside within two weeks but serious cases can also result in long-term hospitalisation of the patient. However, today's modern ovarian stimulation procedures allow doctors to minimise the occurrence of severe forms of hyperstimulation syndrome.

The oocyte is a female germ cell located inside the follicle. The moment the oocyte grows and is released from the follicle, a mature egg (ovum) is formed.

An egg maturation or quality disorder that can cause problems with fertilisation; IVF offers the possibility of retrieving eggs with targeted stimulation and laboratory support.

If the result of a semen analysis shows that the concentration of sperm in the ejaculate is lower than the lower limit of the established standard (15 million sperm per millilitre of semen), then this is oligospermia. The most common causes of low sperm production include hormonal problems, blocked ducts, infections, side effects of certain medications, and lifestyle factors - e.g. excessive alcohol consumption, smoking or frequent bathing in hot water or saunas.

This is a hormone essential for maintaining pregnancy; it is often given as a supplement after an embryo transfer to promote implantation.

A drug containing progesterone (a naturally occurring female sex hormone) that acts on the lining of the uterus during assisted reproduction - it enhances the probability of retention of a fertilised egg. This is why Progesterone is used before the introduction of the embryo in an IVF cycle and, if pregnancy occurs, throughout the first trimester.

A condition in which couples fail to conceive despite regular and unprotected sexual intercourse; this problem can be caused by various factors, including hormonal disorders, genetic predispositions, anatomical abnormalities or lifestyle. Diagnosis of primary infertility usually involves a comprehensive examination of both partners to identify the cause and suggest appropriate treatment, which may include hormonal therapy, surgery or assisted reproduction such as IVF.

It is recommended to take a pregnancy test approximately 14 days after an embryo transfer. A blood test is more accurate than a home pregnancy test. A blood test measures the level of the hormone hCG, which is produced after successful embryo implantation, and it can detect pregnancy earlier than a urine test. Testing too early can lead to a false negative result, as the hCG level may not be high enough. To confirm pregnancy, a repeat blood test is often recommended to monitor the dynamics of hCG growth, which helps to better assess whether the pregnancy is developing properly.

A hormonal disorder that causes irregular ovulation and the formation of cysts on the ovaries; PCOS is a common cause of infertility that can be resolved with IVF or IUI. The syndrome is often associated with insulin resistance, elevated levels of male hormones (androgens) and metabolic problems. Treatment includes lifestyle changes, hormone therapy and assisted reproduction, depending on the severity of symptoms and the patient's individual needs.

In the luteal phase of the menstrual cycle, many women suffer from premenstrual syndrome, when the falling level of oestrogen and high levels of progesterone lead to certain physiological and psychological changes. About one week before menstruation, women may experience tender breasts, weight gain, headaches, muscle and joint pain and loss of appetite, or an increase in appetite. The most common mental symptoms of PMS are depression, anxiety, mood swings, poor sleep and nervousness.

PICSI (Intracytoplasmic Injection of Preselected Sperm) is a method that only allows mature sperm to be selected for egg fertilisation. Sperm are selected in a petri dish covered with a layer of hyaluronan, which can bind mature sperm. We have replaced the PICSI method with the more modern FERTILE PLUS method at our clinic.

This method is designed to screen embryos for structural changes in chromosomes that can lead to miscarriage or genetic disorders. This test helps identify embryos with a balanced chromosome arrangement, thereby increasing the chance of successful implantation and a healthy pregnancy. PGT-SR is especially recommended for couples with confirmed chromosomal translocations or other structural abnormalities in their family history.

This is genetic screening of embryos before they are transferred to the uterus, the aim of which is to detect genetic abnormalities, such as aneuploidy, and thus increase the chances of a successful pregnancy.

PESA (Percutaneous Epididymal Sperm Aspiration) is a minor surgical procedure, that helps obtain sperm even if transport of sperm between the epididymis and urethra is impaired. Sperm are aspirated from the epididymal ducts using a thin puncture needle.

A specialised field that studies the influence of the immune system on fertility, pregnancy, and reproductive success; immune imbalances can cause recurrent miscarriages, failed embryo implantation or complications during pregnancy. Reproductive immunology testing helps identify immune factors that may be preventing pregnancy and propose targeted treatments to increase the chances of a successful pregnancy.

The release of an egg from the ovary without medical intervention or hormonal stimulation; this process occurs spontaneously within the natural menstrual cycle and is key to natural conception. In women undergoing IVF treatment, spontaneous ovulation is usually suppressed with hormonal therapy to prevent premature release of the egg and ensure its optimal quality for retrieval and fertilisation in the laboratory.

One criteria of a semen analysis that evaluates the shape of the sperm; an abnormal shape can affect the sperm's ability to fertilise an egg.

A man who donates sperm for another couple's fertility treatment; donors are carefully selected based on their health and genetic history.

A man who donates sperm for another couple's fertility treatment; donors are carefully selected based on their health and genetic history.

Semen analysis is a microscopic examination of sperm to determine the number, shape and motility of sperm. Sperm is retrieved directly at our clinic in a special discreet sampling room after several days of sexual abstinence. Semen analysis is a basic examination recommended for men who have been unsuccessful in conceiving naturally for more than one year.

The repeated inability to conceive or carry a baby to term after a previous successful pregnancy; this condition can be caused by hormonal imbalances, adhesions in the uterus, poor egg or sperm quality, or changes in lifestyle or health. Diagnosis and treatment of secondary infertility often involves a detailed examination of both partners to identify the cause and suggest appropriate therapy.

The collection of cells from the outer layer of an embryo at the blastocyst stage; the cells are genetically tested to ensure that the embryo is healthy. This method is used in preimplantation genetic testing (PGT), which helps detect chromosomal abnormalities or hereditary disorders. This analysis allows a genetically healthy embryo to be selected, increasing the chances of a successful pregnancy and reducing the risk of miscarriage.

A diagnostic procedure that helps monitor the ovaries and uterine lining during an IVF cycle. It is painless and provides accurate results. It is used to assess follicular growth, egg maturity, and endometrial thickness, which is crucial for timing ovulation and embryo transfer. It can also be used to detect abnormalities such as cysts, polyps or fibroids.

A surgical procedure in which a sample of testicular tissue is removed to find sperm in men with azoospermia.

A surgical method of retrieving sperm directly from the testicles; it is used in men with azoospermia or failure of sperm in the ejaculate. The procedure is performed under local or general anaesthesia and involves the removal of tissue from the testicles, which is then processed in the laboratory to isolate sperm. TESA is often used in IVF with the ICSI method, where the obtained sperm are directly injected into the egg, which increases the chance of fertilisation even in men with very low sperm production.

A condition in which most of the sperm have abnormal morphology; IVF with ICSI often overcomes this problem. This disorder can affect the sperm's ability to penetrate the egg and result in infertility. It can be caused by genetic factors, hormonal imbalances, toxins or lifestyle. It is diagnosed with a semen analysis, which evaluates the morphology, motility and concentration of sperm.

When a couple is unable to conceive, teratospermia may be to blame - a condition in which the sperm cannot penetrate the egg due to its abnormal shape. A semen analysis can reveal this disorder.

Benign growths on the uterine lining that may prevent embryo implantation or cause irregular bleeding; these growths are caused by excessive growth of endometrial tissue and can range in size from tiny nodules to larger masses that distort the uterine cavity. They may be asymptomatic in some cases, but in women with repeated failed implantations or irregular menstrual cycles, their diagnosis and potential removal is an important step in optimising fertility.

Sometimes a small elongated growth appears on the uterine mucosa or cervix, which is usually painless and non-cancerous, but its presence can cause heavy menstruation, bleeding outside menstruation, and pain during intercourse or gynaecological examinations. Undetected polyps can also complicate attempts to conceive, or cause repeated miscarriages. To exclude potential malignancy, a histopathological examination is performed.

Benign tumours of the uterine muscle that can affect fertility or pregnancy; their treatment may necessitate surgical removal.

Vitrification is a modern, quick and safe method of freezing and storing eggs, sperm and embryos. During vitrification, ice crystals that could do damage do not form on cells.

After ovulation, the 'yellow body' (corpus luteum), which produces female sex hormones (mostly progesterone), remains temporarily on the ovary. If fertilisation does not occur, it slowly disintegrates, otherwise it persists and produces hormones that help maintain the pregnancy until the 12th week, when the placenta takes over this task.