The transfer of donated embryos, or embryo donation, is the transfer of embryos given by a couple (after IVF) to a recipient for the purpose of pregnancy. These donated embryos are frozen, and come from couples who have mostly achieved pregnancy through in Vitro Fertilization and are unwilling to use their frozen embryos for future pregnancies. The transfer of donated embryos is a simple treatment, with good results in terms of pregnancy rates. The child born from the treatment is considered the child of the recipient, and not the child of the donor, as in egg donation or sperm donation.
How is the treatment for the transfer of donated embryos?
The treatment for the transfer of donated embryos consists in preparing the uterus of the patient to be as receptive as possible. The preparation of the endometrium can be done in two ways:
Spontaneous cycle: We take advantage of the normal cycle of ovulation in women. Ultrasound controls are performed from the 8 – 10th day of cycle until the moment of ovulation. Usually not more than 2 or 3 controls are needed. The day of the transfer of the donated embryos is determined by the day of ovulation. In URH Garcia of the Real, we carry out the transfer at blastocyst stage i.e., 5 days after ovulation. After the transfer, the patient continues with a hormonal treatment (vaginal progesterone tablets) and a pregnancy test is carried out within 10 days.
Substitutive hormonal cycle: It consists in providing externally (through pills or patches) hormones normally produced by the ovary. Usually, with a single ultrasound and blood test, we can assess whether the uterus is prepared and set a date for the transfer of the donated embryos. In this type of preparation, the date of the transfer can be adjusted depending on the patient’s needs.
How are the embryos to be donated chosen?
To qualify embryos as suitable for embryo donation the medical team will assess the physical health of the donors in order to avoid, as far as possible, the transmission of diseases. Likewise, the age of the female donor, at the time of the vitrification of the embryos, should be under 36 years of age. We also take into account the physical characteristics of the recipients (race, blood type, height, color of hair and eyes…), giving priority to the race, blood type and stature. It is difficult to adjust the rest of the features given that the embryos already exist, unlike what it is done in a process of insemination with donor sperm or egg donation.
What is the probability of pregnancy with the transfer of donated embryos? Is it important that the embryos are frozen?
The pregnancy rate after the transfer of donated embryos is around 40%. It should be taken into account that they are very good prognosis embryos, because they come from young women and couples who have already achieved a pregnancy. This means that the success is greater than the one of a normal frozen embryo transfer. Most of the embryos will endure the thawing (90%) and their probability of implantation is similar to that achieved with fresh embryos.
Can the patient choose the number of embryos to be transferred?
The number of embryos donated for transfer not always depends on our will. Although the patient might want 2 embryos transferred, it is possible that at the time of thawing only 1 survives. In that case a single embryo will be transferred, as we cannot mix, in a single transfer, donated embryos from different couples. In any case, the probability of pregnancy by transferring 1 or 2 embryos is very similar in our Clinic. Transferring 2 embryos only increases the risk of multiple pregnancy.
What studies are needed before a transfer of donated embryos?
The studies needed are quite simple. In the case of the woman in addition to a recent gynecological checkup, we need a blood test, a transvaginal scan, and a vaginal and endocervical culture. In the case of the male only a blood test is needed.
If you are interested in obtaining more information or doing a transfer of donated embryos with us, do not hesitate to request an appointment for a free consultation with us, or call 917401690.
Dr. Laura Blasco Gastón – Gynecologist specialized in Assisted Reproduction
