In Vitro fertilisation (IVF) with donor eggs and partner sperm
It consists of fertilising the donor eggs with the sperm of the recipient woman’s partner in the laboratory. The embryos obtained as a result of this insemination are transferred to the woman’s uterus. The patient undergoes medical treatment which prepares her uterus to receive the transferred embryos.
According to Spanish law the egg donation is anonymous (the donor and the recipient cannot know each other neither in the present nor in the future) and it must be done under their own free will (commercialization of gametes and embryos is banned by law. However, donors receive an economic reward for their commitment and the time they invest in the donation). The law states that donors should be between 18 and 35 years old.
IVF with donor eggs procedure
First step (donor selection) The donors are selected according to very strict medical criteria. First of all they undergo a clinical examination to make sure that their ovaries are healthy and they have no transmittable pathologies (infectious or genetic). Before donating her eggs, the donor has a blood test in order to rule out the risk of any transmittable infectious diseases (hepatitis B and C, HIV, cytomegalovirus, gonococcus, chlamydia and syphilis) and in order to determine her blood group, basal hormone level and karyotype. A cytology test is carried out as well as a neck of the uterus smear and a pelvic ultrasound scan.
These results are studied by a doctor who also verifies by means of a questionnaire the absence of any genetic family illnesses while the psychologist evaluates the donor’s mental health. Finally, the donor signs a consent form according to Spanish law in which she agrees to donate her eggs to a couple who want to have a child and whose identity she will never try to find out.
Second step (donor stimulation) The donors have to undergo a two-week ovarian stimulation treatment, which consists of administering subcutaneous hormonal injections and whose development is controlled by means of ultrasound checks and blood tests (five respectively). The egg collection is carried out by way of puncturing under sedation.
Third step (fertilisation and embryo transfer)
As with partners’ gametes IVF, the eggs are cultivated in culture medium while the sperm is prepared (as with Artificial Insemination). Later on the biologist carries out the insemination which consists of placing the sperm (between 50.000 and 100.000 motile spermatozoa) in the culture medium with the eggs. The following day a check is made on how many eggs have been fertilised and the embryos are transferred to the recipient woman’s uterus two or three days after the egg collection. Two or three embryos are selected for the transfer. They are introduced in the uterus together with a small quantity of culture medium in a fine catheter. Under an abdominal ultrasound control, the gynaecologist places the catheter up to the end of the uterus where the embryos are deposited.
Fourth step (cryopreservation) The non transferred embryos are frozen in liquid nitrogen (cryopreservation) and stored correctly identified in the embryo bank of the laboratory. These embryos can be used in future cycles if pregnancy does not occur at the first attempt. Obviously, it simplifies the process and makes it cheaper, although the pregnancy rates decrease.
This technique is recommended in...
1. Women with ovarian failure. These are women whose ovaries are not able to produce eggs any more. It can occur for many reasons:
Premature menopause:
premature ovulation stoppage (before 40 years old). This situation, which affects approximately half of the egg recipients, has different causes:
- Indiopathic or unknown (the most common)
- Genetic
- Immunological or autoimmunologic disorders
- Latrogenic, meaning consequences of medical procedure such as ovarian surgery, chemotherapy or radiotherap
- Natural menopause: In this case the egg donation has to be evaluated according to the age and the general health of the woman.
2. Women without ovarian failure. These are women whose ovaries are able to produce eggs but they are of insufficient quality, or women who are carriers of genetic illnesses or chromosomal anomalies. The egg donation is recommended in the following cases:
- Repeated IVF failures. In some cases the pregnancy does not occur in “conventional” Assisted Reproduction Techniques. There can be various reasons:
- Low response to the ovarian stimulation
- Repeated failure due to poor egg quality
- Repeated implantation failure of apparently normal embryos
- Hidden ovarian failure. These are women who have regular periods but suffer from hormonal alterations which indicate an ovarian failure in its initial stage.
- Women over 43 with a normal menstrual cycle.
Fertility has a direct connection to age and therefore in some cases women older than 43 are recommended to undergo IVF treatment with donor eggs. Moreover, at this age miscarriages and foetus chromosomal alterations rates increase.