4 Special Techniques
in IVF

Advances in molecular and cellular genetics techniques enable couples to have healthy children without genetic and chromosomal abnormalities. The genetic material that is passed from generation to generation and is required for the normal development of every organism is organised in structures, called chromosomes, in the nucleus of cells. Approximately 50% of automatically aborted embryos have chromosomal abnormalities.

Numerical chromosomal abnormalities are associated with the development of genetic syndromes in humans, such as chromosome 21 trisomy or Down’s syndrome. Another type of genetic abnormalities are monogenic abnormalities, which are associated with diseases such as cystic fibrosis and thalassaemia or thalassemia interferon.

Pre-implantation genetic testing of the embryo is done by biopsy of the embryo during its development: usually on the third or fifth day (blastocyst stage) of its in vitro development.

PGT-A (Preimplantation Genetic Testing for Aneuploidies)

Preimplantation Genetic Testing for Aneuploidies (PGT-A) is recommended for couples with infertility problems undergoing an IVF cycle and aims to analyse the whole genome for chromosome abnormalities in the embryos in order to increase the chances of implantation in the uterus.

Suggested in pairs:

• • with a history of miscarriages
  • with multiple failed IVF attempts
  • where the woman is of advanced reproductive age

PGD (Preimplantation Genetic Diagnosis)

Preimplantation genetic diagnosis (PGD) has been practiced in recent years by infertility specialists, in combination with IVF in case the parents are suffering from or are carriers of a disease. This technique detects genetic diseases before the embryo is transferred to the uterine cavity.

Apoptosis or otherwise programmed cell death is a physiological mechanism of cell destruction, which ensures the proper growth of the organism and maintains its homeostasis. Cells undergoing apoptosis show various structural alterations, mainly in their nucleus, such as fragmentation of their genetic material (DNA), i.e. the breaking of their DNA chain into shorter segments.

This test allows us to express in percentage terms the presence of apoptotic sperm in each sample.

Apoptosis greater than a critical percentage can result in the prevention of normal fetal development at an early stage, miscarriages, neonatal abnormalities, etc.

The embryo settles in the endometrium a few days after fertilisation. Under normal circumstances, the embryo must “viscerally” erode the transparent zone, causing it to thin and the embryo to hatch and attach to the endometrium to settle (implantation).

If the zone is already thicker than normal, hatching is theoretically hindered.

Therefore, during IVF, the embryologist can facilitate the embryo’s hatching by opening a hole in the transparent zone (either by chemical erosion or by means of a special laser adapted to the microscope), before the embryo is transferred to the uterine cavity.

This process is relatively easy. It literally involves a micro-injury to the endometrium using a thin catheter, with the ultimate goal of increasing the implantation rate of the fertilised embryo. This injury to the endometrium causes a regeneration process in which hormones and chemicals are released and the new piece of endometrium that grows is considered more “friendly” to the embryo. The best time for this process to take place is around day 2 of the cycle. It is not painful and no preparation of the woman is needed beforehand as no anaesthesia is used.