In Vitro Fertilization - IVF or IVF

Generality

In vitro fertilization (IVF or IVF) is a procedure developed by the Englishman Robert Edwards, thanks to whom - in 1978 - Louise Brown was born, the result of his studies and the first human being conceived in a test tube.

The technique is based on the collection of oocytes via the vagina and their subsequent fertilization in the laboratory, using the spermatozoa of the partner or of an anonymous donor. Similarly, if the female germ cells are unsuitable for generation, oocytes from a donor outside the couple can be used.

Once fertilization has taken place, from one to three embryos are simultaneously transferred to the woman's uterus, the natural site for their development.

When using

In vitro fertilization is traditionally used in cases of alteration and obstruction of the tubes (tubal sterility) or of their congenital or acquired lack (for example by surgical removal).

As seen in the article dedicated to female infertility, all these conditions prevent or make it very difficult for the egg cell to meet the spermatozoa. The union of the gametes is then carried out in the laboratory overcoming the organic impediment.

The possibility of giving a pregnancy to women who have had their ovaries removed, to those missing from birth and in all cases of ovarian failure should also be considered. Lacking this essential organ for female hormonal regulation, it is necessary not only to resort to oocytes donated by another woman, but also to guarantee the implantation and progress of the pregnancy through the association of an appropriate hormone replacement therapy.

The same technique can be used in the presence of endometriosis, poor sperm viability or when artificial insemination fails.

How it is done

First of all, the woman's ovulation is controlled by hormonal stimulation with the aim of producing a multiple ovulation. The need to collect more oocytes derives from a simple consideration: the more embryos transferred to the uterus, the greater the chances of implantation.

The oocytes are collected under ultrasound guidance, mostly under general anesthesia, selected and allowed to incubate at 37 degrees, for 24-48 hours, in prepared liquids and with a selected population of spermatozoa.

After this period of time, if fertilization has taken place, as happens in 70-90% of cases, the embryos are transferred to the uterus; in general, their number is chosen according to the age of the woman: 1-2 if she is less than 36 years old, 2-4 in older women. Those remaining, called supernumeraries, are frozen and stored for years.

Conservation of embryos

The need to preserve these embryos arises from the fact that repeated ovarian stimulation operations, in addition to being expensive in economic terms, can be dangerous for the woman's health. Seen from this point of view, the freezing of embryos in liquid nitrogen (-196 ° C) represents a precious resource if the first attempts to give birth to a child should fail.

In Italy, however, it is possible to produce no more than three embryos at a time, that is the number necessary for a single and simultaneous implant. An alternative to freezing embryos, banned in our country, could be to do the same with egg cells. This possibility raises a much smaller number of ethical problems; unfortunately, however, the biological characteristics of the egg cell make the operation rather delicate and it is still early to assess whether its freezing is completely harmless for the health of the unborn child.

Chance of success

Of the 2-4 embryos transferred into the woman's uterus, at least one should be able to implant and thus establish the long-awaited pregnancy.

The number of embryos is then chosen by mediating between the possibility of failure and a possible multiple pregnancy.

This is an important choice because a multiple pregnancy could compromise the outcome of the pregnancy itself and the health of the mother and fetuses. On the other hand, however, the success rates of in vitro fertilization are not very high, so much so that we talk on average by 35% if the woman is under 36 years old, up to percentages of less than 9% for over 40s. Furthermore, the abortion rate is quite high, close to 20%, as is the risk of twin pregnancies. There also appears to be an increased likelihood of premature births and underweight babies.

Law and Ethical Aspects

The discussed limitations of the Italian law concern above all in vitro fertilization, for which limits have been imposed on the number of embryos to be produced, the prohibition of cryopreserving them and the obligation to transfer them all at the same time into the uterus. This law, deeply contested by many, but in harmony with the ethical sensitivity of others, it is the result of a series of considerations, first of all: what to do with residual frozen embryos? Use them for research, since they are a source of stem cells and can evaluate the teratogenic effects of new drugs, or, more simply, destroy them?

Questions that we deliberately leave open to give space to the sensibility and morale of the reader. Questions to which the Italian law - heavily influenced by confessional choices - has given clear answers: no to experimentation on embryos, no to their freezing. These and other limitations, such as the impossibility of carrying out pre-implantation diagnosis, in order - for example - to know the concrete possibility that the unborn child may have hereditary diseases, represent an insurmountable constraint for many couples.

However, an obstacle that can be circumvented. turning to structures in other states where the regulations on the matter are less restrictive. In fact, we cannot forget the increasing number of couples who go abroad in search of a child who does not arrive here, precisely because of the limitations imposed by this law. A journey of hope, expensive, sometimes too much for the budgets of the partners, but which in many cases represents the only way to crown a dream that is priceless, because most of the time it is the result of a love that should at least make people think - or at least say they do - of this word their reason for life.