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Key Concepts in Assisted Reproductive Technologies (ART)


Modern reproductive medicine offers numerous options for couples struggling with infertility. Assisted Reproductive Technologies (ART) encompass a wide range of methods, and understanding key terms in this field will help navigate treatment options more effectively.

What is Infertility?

Infertility is diagnosed when a couple fails to achieve pregnancy after one year of regular, unprotected intercourse. For women over 35 and men over 40, this period is reduced to six months. Infertility affects men and women equally: in approximately one-third of cases, infertility is attributed to the male partner, in another third to the female partner, and in the remaining cases, both partners are affected. Statistics show that about 1 in 10 people experience infertility globally, and this rate is rising due to lifestyle, environmental, and health factors .

Main ART Methods

In Vitro Fertilization (IVF)

IVF is the process of fertilizing an egg outside the body. The egg is retrieved from the woman's ovaries and fertilized by sperm in a laboratory, where the resulting embryo is cultured for several days before being transferred to the uterus. IVF is one of the most effective ART methods, with success rates ranging from 30% to 50% depending on maternal age .

Intracytoplasmic Sperm Injection (ICSI)

ICSI is used in cases of male infertility. A single sperm is injected directly into the egg under a microscope, increasing the chances of successful fertilization and embryo development. This method is particularly effective in cases of severe male factor infertility, and it is reported that over 80% of eggs injected with sperm via ICSI are successfully fertilized .

Are Children Born Through ICSI Healthy?

While ICSI slightly increases the risk of birth defects, the overall risk remains low. Studies have shown that the risk of congenital anomalies after ICSI is approximately 4%, compared to 1.5%-3% in natural conception . However, most children conceived through ICSI are born healthy and show normal development.

Which Gender is More Common After ICSI?

A study conducted in 2010 in Australia showed that boys were more likely to be born after standard IVF (53%) than after ICSI (50%) . This suggests that the fertilization method may have a minor influence on the gender ratio, though more research is needed to confirm this trend.

PICSI

PICSI is an enhancement of ICSI, where sperm selection is done using hyaluronic acid. Research indicates that this method allows for the selection of more mature and genetically viable sperm, which improves fertilization rates and embryo quality .

Intrauterine Insemination (IUI)

IUI involves placing processed semen directly into the woman’s uterus to facilitate conception. It is commonly used in cases of mild male infertility or when there are issues with sperm motility. IUI has a success rate of about 10%-20% per cycle .

Diagnostic Procedures

Semen Analysis (Spermogram)

Semen analysis is a fundamental diagnostic tool that evaluates sperm quality based on parameters such as:

  • Azoospermia: absence of sperm in semen,

  • Asthenozoospermia: reduced sperm motility,

  • Teratozoospermia: abnormal sperm morphology.

Semen analysis helps identify specific issues that may hinder conception, with normal parameters defined by the World Health Organization (WHO) as sperm concentration above 15 million/ml, progressive motility above 32%, and normal morphology above 4% .

HBA Test (Hyaluronic Binding Assay)

The HBA test assesses the sperm's ability to bind with hyaluronic acid, an indicator of sperm maturity and fertility potential. Studies show that HBA results correlate with better outcomes in ART, particularly in ICSI cycles .

MAR Test

The Mixed Antiglobulin Reaction (MAR) test is used to detect anti-sperm antibodies, which can bind to sperm and hinder fertilization. MAR testing is crucial for diagnosing immunological infertility, particularly when unexplained infertility is suspected .

Additional Procedures for Women

Ovulation Stimulation

Ovulation stimulation involves using gonadotropins or other hormones to induce the maturation of multiple eggs in a single cycle. Studies show that this increases the chances of successful IVF by 30%-40%, depending on the woman's age and ovarian reserve .

Follicular Aspiration

This minimally invasive procedure involves retrieving mature eggs from the ovaries under ultrasound guidance. It is an essential step in IVF and egg cryopreservation, with success rates for egg retrieval ranging between 80%-90% in stimulated cycles .

Embryo Culture

After fertilization, embryos are cultured in the laboratory for up to 5-6 days, reaching the blastocyst stage. Long-term culture allows embryologists to select the most viable embryos, with success rates for blastocyst transfer reaching up to 50% .

Genetic Testing and Cryopreservation

Preimplantation Genetic Diagnosis (PGD)

PGD is performed to detect chromosomal and genetic abnormalities in embryos before transfer. It is particularly beneficial for couples with a history of genetic disorders or advanced maternal age, where aneuploidy risk is increased. Success rates for PGD with IVF are approximately 45%-50% .

Cryopreservation (Vitrification)

Cryopreservation involves freezing reproductive cells (eggs, sperm, or embryos) for future use. Vitrification is a modern technique that reduces the formation of ice crystals during freezing, preserving cell integrity. Embryo survival rates after thawing reach up to 99%, and the success rate for frozen embryo transfer (FET) cycles is comparable to fresh transfers .

Advantages of Cryopreservation:

  • Reduces the need for repeated ovarian stimulation cycles.

  • Allows embryos to be stored for several years, maintaining high viability.

  • Increases flexibility for couples in planning subsequent cycles.

Can PGT Be Performed on Frozen Embryos?

Yes, Preimplantation Genetic Testing (PGT) can be performed on frozen embryos. The embryos are thawed, and if they have a sufficient number of viable cells, they can be tested for chromosomal abnormalities. Studies show no significant difference in the success rates of PGT performed on fresh versus frozen embryos .

How Many Embryos Can Be Obtained?

On average, about 4.5-5 embryos are successfully created from 10 retrieved eggs, as not all eggs fertilize or develop into viable embryos. This equates to approximately 50% of eggs resulting in embryos .

Frozen Embryo Transfer (FET)

Frozen embryo transfer is a common practice in ART, where embryos previously frozen via vitrification are transferred into the uterus. FET can be done in a natural cycle or in a hormone-controlled cycle. Studies have shown that FET success rates are comparable to fresh transfers, with live birth rates ranging between 30%-50%, depending on maternal age .