Infertility Terms Glossary

Assisted hatching: An advanced micro-manipulation technique that involves creating a small cut in the outer shell, or zona, of an embryo using a laser or a special acidic solution. This technique is designed to help with embryo implantation for certain subgroups of patients in whom this may be less likely to naturally occur.

Azoospermia: The complete absence of sperm in a male’s ejaculate. This condition does not necessarily mean that there is no sperm present, and often times MESA or TESE (see below) are carried out to search for the presence of sperm from various parts of the testicel.

Blastocyst: An embryo that has been developing for 5 to 6 days following fertilization. The blastocyst is cultured (grown) out to this stage in the laboratory using specialized media (chemical solutions) that continually nourish it as it develops and grows. Transfer of blastocysts into the uterus, or Blastocyst Transfer (see Embryo Transfer below) may offer the advantage of reducing the incidence of multiple pregnancy while maintaining a high pregnancy rate.

CCS (comprehensive chromosomal screening): a genetic test of cells from a blastocyst embryo to determine home many chromosomes are in an embryo. This test isolates embryos that have too many or too few chromosomes, which may not implant to the uterine wall once transferred, or may cause birth defects in pregnancies brought to full term. Click here for more information.

Cryopreservation: A procedure that involves freezing and storage of any excess embryos that are not immediately transferred into a patient’s uterus during a fresh treatment cycle. These embryos can then be used in future transfer cycles, thus avoiding the need for undergoing an additional egg retrieval procedure. Cryopreservation can also be performed with sperm specimens, and recently has started to become used with eggs (oocytes) as well.

Egg donation: An extremely successful treatment alternative for patients with a very poor prognosis for IVF success using their own oocytes (eggs), such as women with premature menopause, advanced reproductive age (e.g. over 40 years old), elevated FSH levels (e.g. > 12 U/L), etc. Egg donation can be performed with a known egg donor (e.g. a relative or friend), or an anonymous donor who would be matched with the patient as per her desires, and following an intense and comprehensive screening process. The egg donor undergoes the IVF/Egg retrieval, and the eggs would then belong to the patient (recipient), who would undergo an embryo transfer procedure into her own uterus following fertilization of these eggs with her husband’s, or donor, sperm.

Egg retrieval: The procedure by which the eggs are collected from a woman’s ovaries to then be fertilized with the partner’s (or donor) sperm cells. The egg retrieval is performed with the use of ultrasound guidance for clear visualization of the patient’s ovaries, and involves insertion of a sterile needle through the patient’s vagina directly into the ovaries to aspirate (suck) out the eggs to be handed off to the laboratory personnel. The egg retrieval is generally performed on site in the fertility center with an experienced anesthesiologist present to give intravenous anesthesia to the patient, thus rendering the procedure pain-free.

Embryo: The cellular component that is formed when a male sperm cell fertilizes a female egg (oocyte). The embryo is the element that is transferred into a patient’s uterus in hopes of implanting and yielding a growing fetus.

Embryologist: The specialized laboratory individual who has advanced training in the field of sperm, egg, and embryo fertilization, culture, and management, and who functions as the fertility center’s Laboratory Director. Occasionally, a fertility center may be fortunate to have a doctoral, or PhD-level, embryologist as their IVF Laboratory Director.

Embryo transfer: The procedure by which an embryo, or embryos, is/are placed transvaginally up into a patient’s uterus in hopes that implantation will occur, thus leading to an ongoing pregnancy. This procedure is performed using a specialized catheter and with abdominal ultrasound guidance to assist the physician in precise placement of the embryo(s) within the uterine cavity. The embryo transfer is generally performed 5 days following fertilization of the eggs, at blastocyst stage.

Endometriosis: Condition in which uterine lining grows outside the uterus. This illness is characterized by pain during menstruation, heavy or irregular periods, chronic fatigue, fever, pain during intercourse, and infertility, and is present in 4-10% of women. It can be treated with pain medications, hormone therapy and surgery.

Fertilization: The genetic process by which a male sperm cell enters into a female egg, leading to a union of the DNA (genetic or chromosomal material) of these 2 cells, and thus the formation of an embryo. In general, depending on the quality of both the sperm and egg cells themselves, as well as the technique of fertilization that is used in the laboratory, ~ 60 – 90% of all mature eggs that are retrieved during an IVF cycle can be expected to become fertilized.

Frozen Embryo Transfer (FET): The procedure by which embryos excess embryos that were frozen for future use from a prior “fresh” IVF cycle in which an egg retrieval was performed are thawed in the laboratory, and transferred into the patient’s uterus in hopes of achieving pregnancy. FET cycles offer the patient (couple) the opportunity to conceive without the need for ovarian stimulation and an additional egg retrieval procedure, and are generally performed with the use of simple medication protocols.

Gestational carrier: A gestational carrier, commonly known as a surrogate, is an individual who carries a pregnancy for a couple in which the female patient is not able to do so. This may be due to factors such as considerable damage to her uterus, advanced medical problems that would make pregnancy medically risky, or having undergone a hysterectomy with preservation of her ovaries. The patient would undergo an IVF procedure with her eggs being retrieved, fertilized with her husband’s or donor sperm, and the resultant embryo(s) transferred into the uterus of the gestational carrier who would carry the pregnancy to term for the patient. There are legal steps that are then undertaken in which the couple would receive their child(ren) following delivery, and an attorney who specializes in reproductive law is often involved in the process.

Intracytoplasmic sperm injection (ICSI): An advanced microscopic technique performed in the laboratory that involves the injection of one sperm cell directly into one egg cell in hopes of achieving fertilization and formation of an embryo. ICSI is a technique of gamete (sperm/egg) micro-manipulation, or assisted fertilization, and the resultant fertilized eggs (early embryos) are then allowed to grow and mature in the sterile laboratory conditions in a manner similar to that of standard IVF. ICSI is frequently used in cases where there is some form of compromise in the male’s sperm quality, quantity, or functionality that could interfere with standard sperm-egg fertilization.

Intrauterine insemination (IUI): A procedure also known as artificial insemination, in which sperm from the male partner’s ejaculate (or donor sperm) is processed in the laboratory to maximize its quality, and then deposited into the female patient’s uterus at the time of ovulation using a specialized sterile tube or catheter. It is also commonly performed following treatment of the female patient with fertility enhancing medications or ovulatory stimulants (superovulation or ovulation induction). Click here for more information.

In vitro fertilization (IVF): The “gold standard” of modern-day fertility therapy. IVF involves the stimulation of a woman’s ovaries to produce multiple eggs, the aspiration of these eggs via the egg retrieval, the fertilization of the eggs in the laboratory, and the transfer of the resultant embryos into the patient’s uterus in hopes of achieving pregnancy. IVF is rapidly becoming the most popular choice of treatment for couples with various types of infertility, including blocked tubes, sperm and/or egg quality issues, endometriosis, and even unexplained cases. It is generally accepted as the most successful and fastest method available to achieve pregnancy. Click here for more information.

Micromanipulation: The specialized microscopic procedures performed by trained laboratory personnel involving the handling and fertilization of sperm and eggs, as well as the preparation for transfer of embryos or blastocysts. These techniques include Assisted hatching and ICSI.

Microsurgical epididymal sperm aspiration (MESA): In cases where there is a complete absence of sperm in the ejaculate, commonly due to a blockage such as in gentlemen who have previously undergone a vasectomy, microsurgical epididymal sperm aspiration (MESA) or is performed by a specialized urologist for retrieval of the sperm. These sperm are aspirated from the epididymal tubes (tubules) within the testicles, and ICSI is then carried out.

Oocyte: The medical term for a female egg cell.

Ovarian Hyperstimulation Syndrome (OHSS): A condition that arises when a patient has an excessive response to the fertility medications, and this results in bloating, cystic enlargement of the ovaries, and in more advanced cases, fluid buildup in the pelvic cavity or rarely in the lower lungs. Patient are monitored very closely to avoid development of OHSS, and if it does occur (generally infrequently), bed rest or aspiration of the pelvic fluid may be needed.

PCOS (polycystic ovary syndrome) – illness that interferes with ovulation and egg development in the ovaries, often leading to infertility or subfertility. PCOS affects roughly 5-10% of women and is evidenced by irregular periods or no periods, high blood pressure and obesity. Pregnancy is possible with PCOS, often with weight loss and insulin management.

Preimplantation genetic diagnosis (PGD): An advanced micromanipulation technique used in conjunction with in vitro fertilization which helps increase the likelihood of genetically normal embryos to be selected for transfer to the uterus. PGD involves the microsurgical removal and biopsy of one blastomere (cell) from a six to eight cell embryo, and subsequent genetic analysis of this cell in a specialized laboratory. It is often performed in cases where both the male and female partner carry the gene for a particular disorder, thus avoiding the transfer of embryos that would contain both copies of the gene which would otherwise lead to a baby that would be afflicted with this disorder. PGD is occasionally performed for gender determination in couple who wish to undergo family balancing as well. Click here for more information.

Superovulation: A treatment in which the female patient uses injectable fertility medications to induce the development, maturation, and subsequent ovulation of multiple eggs that can be retrieved and fertilized during an IVF procedure. Patients undergoing superovulation therapy are closely monitored with blood and ultrasound testing to optimize both the efficiency, as well as the safety of their treatment process.

Testicular sperm extraction (TESE): See microsurgical epididymal sperm aspiration (MESA) above. A similar procedure as MESA, however with TESE, the sperm is microsurgically aspirated directly from the testicle by a specialized urologist as it is often performed in cases where the absence of sperm in the ejaculate is not necessarily due to some form of blockage.


If you have any questions about infertility terms not found in this glossary, please call our Edison office at 732-339-9300 or contact us online.