IN VITRO FERTILIZATION (IVF)
In vitro fertilization is performed in the laboratory by fertilizing retrieved oocytes with spermatozoa in special culture media. This method requires couples having a sufficient number of oocytes and spermatozoa with good motility.
INTRACYTOPLASMIC SPERM INJECTION (ICSI)
ICSI is performed by injecting a single spermatooan into every mature oocyte. This method overcomes problems of oligospermia (low sperm count) and azoospermia (no spermatozoa in semen sample) with sperm aspirated by testicular biopsy (TESA). ICSI is also performed in cases of previous failed oocyte fertilization in an IVF attempt.
EMBRYO CULTURE- BLASTOCYSTS
Fertilized oocytes are cultured in specialized culture media that mimic the natural female tract environment. The embryos develop by continuous mitotic divisions, from 2-4 cells (day2) to about 500 cells (day 5) at the blastocyst stage. Culturing embryos to the blastocyst stage provides an alternative strategy attempting to select the best embryos for the embryo transfer and reduce multiple conceptions. However, this approach in not suitable for all couples and requires certain conditions.
The embryo transfer is a simple procedure by which the embryos are loaded into a soft catheter and inserted through the cervix under ultrasound guidance to the uterine cavity whereby the embryos are released. Two weeks later a pregnancy test is performed.
Embryo cryopreservation is performed when a surplus of good quality embryos is available at the end of the IVF treatment, as well as in situations at high risk of ovarian hyperstimulation and obvious premature follicular luteinization. The embryos are cryopreserved in liquid nitrogen under specific conditions for a number of years. The embryos can be transferred in a future treatment in a natural or artificial cycle.
FROZEN EMBRYO TRANSFER
The cryopreserved embryos are gradually brought to body temperature and cultured. Due to stress conditions during thawing, a small number of embryos or cells (blastomeres) may not survive. The best-survived embryos are selected for the frozen embryo transfer.
This technique provides an alternative strategy whereby a thinning of the zona pellucida that surrounds the embryo is performed in an attempt to improve implantation.
EMBRYO BIOPSY- PREIMPLANTATION GENETIC DIAGNOSIS (PGD)
Embryo biopsy is required in situations where there is risk of inheritance of a genetic disorder (e.g. β-thalassemia, cystic fibrosis). It is a specialized technique whereby one or two cells of the embryo or few cells of a blastocyst are carefully removed and are sent to a genetics laboratory for chromosomal analysis and genetic diagnosis. Only healthy embryos are selected for the embryo transfer.
This method of cryopreservation improves the results in oocyte freezing. This alternative strategy is applied in situations of premature ovarian failure, prior to chemotherapy, delayed marriage, or absence of a male partner. Retrieved oocytes are vitrified and held in a ‘glass-state’ until future use.
A sperm sample is given in a sterile urine cup to the laboratory for analysis. A macroscopic, as well as microscopic analysis is performed for various parameters (volume, concentration, motility, survival rate, morphology and presence of other cells). The sperm analysis is not the sole criterion for male fertility potential, as is provides one aspect of sperm quality.
With the use of specialized media (density gradients) and centrifugation, non-motile spermatozoa, as well as sperm with abnormal morphology and other cells, are removed from the sperm sample, thereby obtaining a high concentration of good quality spermatozoa for IVF or intra-uterine insemination.
In cases of severe male oligo-asthenozoospermia (low sperm concentration and motility), or if the male partner is not present on the day of oocyte retrieval, or prior to chemotherapy, sperm samples are cryopreserved in liquid nitrogen until use for future IVF treatment.
INTRAUTERINE INSEMINATION (IUI)
Basic requirements for IUI are that the male sperm count and motility meets the criteria of the World Health Organization (WHO) and that the fallopian tubes of the female are patent. A sperm preparation is performed to select the best sperm fraction. The sample is then loaded into a soft catheter and released in the uterus. The IUI is a simple procedure and the couple can return immediately to their duties. The IUI can be done after mild hormonal follicular stimulation or in a natural cycle.
TESTICULAR SPERM ASPIRATION/EXTRACTION (TESA/TESE)
In cases of azoospermia (no spermatozoa in the semen sample) a small incision is performed in the testes with the removal of seminiferous tubule tissue that is processed in the attempt to find spermatozoa for fertilization of oocytes. ICSI is then applied.
For this procedure there is a strict national legislation that is followed. A couple or single female patient can receive oocytes anonymously from a young oocyte donor when there is a problem of severe ovarian failure or premature menopause. The egg donor undergoes ovarian hyperstimulation. Consent forms from both parts are signed. The success rates for this method are very high.