Medically assisted procreation with blastocyst culture
When is this procedure indicated?
The following couples are eligible for Level II PMA techniques:
- subfertile/infertile heterosexual couples who have had unprotected sex in the last 12 months, without natural conception;
- fertile/infertile couples in which one or both partners are carriers of a monogenic disease and/or structural chromosomal abnormalities;
- fertile couples who have a child affected by monogenic diseases and/or structural chromosomal abnormalities.
How is it performed?
The female partner undergoes controlled ovarian stimulation, which consists of taking drugs aimed at obtaining multiple follicular growth for a period ranging from 10 to 20 days in order to obtain more mature oocytes on the day of oocyte retrieval.
The oocyte retrieval procedure is performed trans-vaginally, under ultrasound control, under deep sedation. All follicles present, within certain diameters (>16mm), are aspirated and the follicular fluid obtained is immediately checked for oocytes in the laboratory. At the time of the egg retrieval, the male partner performs the collection of seminal fluid. The collected oocytes are prepared for insemination, which can be done by classical in vitro fertilization or ICSI micromanipulation technique. The most appropriate insemination technique is selected based on the quality of the gametes and the indication for treatment.
Classical In Vitro Fertilization (IVF) consists simply in putting in contact the selected spermatozoids with the harvested oocytes still surrounded by the cells of the outer covering (cells of the oophore cumulus). ICSI is a micromanipulation technique introduced in clinical practice to solve cases of infertility related mainly to a severe male factor but which is also indicated in case of previous failures with IVF technique and in case of limitations in the number of eggs available for insemination. This technique consists of introducing a single selected sperm directly into the oocyte using micromanipulation techniques.
In the days following the fertilization process, a cascade of events leads to the formation of the embryo. To date, the strategy of choice for identifying the most developmentally competent embryo remains the extension of culture to the blastocyst stage. The blastocysts obtained are transferred into the uterine cavity vaginally via a thin catheter. In cases where it is not possible to transfer the embryos due to serious and documented health condition of the woman, not foreseeable at the time of fertilization, it is possible to freeze the embryos, which will then be thawed for future implantation.
Egg retrieval is a method that has a very low incidence of complications. The most frequent are vaginal bleeding, intra-abdominal hemorrhage (hemoperitoneum) and infectious complications (sepsis, abscesses). More rarely, torsion of the ovary, injury to urologic organs (ureter or bladder), or bowel injury may occur. In addition, ovarian hyperstimulation syndrome (OHSS) is a complication of medically assisted procreation treatments, with an incidence of 3-8%, consisting of ovarian enlargement and increased vascular permeability with consequent accumulation of fluid in the pelvis.