The first pregnancy and delivery achieved with egg donation was published by Australian groups in 1983 and 1984 respectively. Since then, the number of treatments performed with this technique has grown exponentially as there are more and more couples with the medical indications to use it.
One of the most important factors for the increasing need to use egg donation is the increase in the average age of women wishing to get pregnant for the first time. Currently in Spain, the average age of women on the birth of their first child is almost 32 and it is similar in most European countries. The advanced age of the woman is one of the main indications, but not the only one as experience over the years has made the range of patients who benefit from egg donation expand. Today, egg donation is the Assisted Reproduction technique with the highest pregnancy rate, irrespective of the age of the female recipient.
The indications established for egg donation are:
- Menopause: natural or iatrogenic
- Ovarian failure
- Advanced age: regardless of ovarían function
- Repeated failures of in vitro fertilization (IVF) cycles with own oocytes
Medical laboratory process::
When speaking of an egg donation, we are talking about performing IVF. From the technical point of view, we will carry out the same processes as in an IVF with one’s own eggs, that is, we obtain eggs and sperm, we fertilise them in vitro to form embryos to cultivate in the laboratory, and then we inject them into the uterus (transfer). However, there are differences:
- • Biological: The oocytes that will be fertilised are from a donor rather than from the patient.
- • Medical:
- Ovarian stimulation and follicular puncture: It will be performed on the egg donor.
- Endometrial preparation- transfer: It will be performed on the recipient.
Until the development of the vitrification technique, oocyte freezing with optimal results was not technically possible, so whenever we talked about egg donation, we would be referring to fresh oocytes. Today it is possible to freeze eggs and obtain fertilization and pregnancy rates similar to the results achieved using fresh oocytes.
Having the benefit of an egg bank, in the same way as having a sperm bank, greatly simplifies and facilitates the planning of the recipient treatment, as we can know the date of the embryo transfer weeks or months in advance.
However, if the donation is done with fresh eggs, the dates are approximate as they depend on many variables: the day of the donor’s period, duration of stimulation, etc
The egg recipient’s treatment:
The egg recipient’s treatment is aimed at preparing the endometrium for the implantation of the embryos. It is important to know that there must be synchronization between the number of days of life of the embryos and the days of the secretory phase of the endometrium. In general, if the embryo is 2 days old, the endometrium should have been acting under the progesterone for 2-3 days, if the embryo is 3 days old, the endometrium should have been 3-4 days … and so on.
Start PG Transfer
EG Embryo at J+2 —————————-0——-1—–2————–
If we work on a natural cycle of the recipient and a stimulated cycle of the donor simultaneously, it is much more difficult to plan the treatment properly and we would have to transfer the embryos at an unsuitable time for the endometrium for a successful implantation. Therefore, we choose to work on an artificial cycle in most cases. Within the artificial cycle, there are different options, depending on the type of organization of the egg donation programme.
Different treatment options:
- Natural cycle: As we said earlier, good synchronization becomes very difficult, even in cases where we use vitrified ovovitos, because the recipient must undergo daily ultrasounds and blood tests (even as often as twice a day), after a certain phase of the cycle in order to determine the exact time of the onset of progesterone production.
- 2. Hormone replacement therapy (HRT): It consists of high-doses of estrogen taken orally or transdermally from the first day of the cycle in patients with ovarian function. The duration of this artificial follicular phase can vary and progesterone is added vaginally on the day of oocyte retrieval or thawing.
The drawback is that in patients with ovarian function, there could be ovulatory leaks, which would produce early secretory changes in the endometrium, making it impossible to carry out an implantation due to endometrium-embryo asynchrony.
- HRT plus pituitary blockage: This involves the administration of a GnRH agonist (normally in depot form) in the luteal phase of the cycle, with the period subsequent to the administration; the HRT is started as in the previous section. The advantage of this protocol is that the pituitary blockage allows us to prolong the artificial follicular phase for 7 weeks without impacting negatively on pregnancy rates, which greatly facilitates synchronization with the donor, in the case of a fresh donation
- Oral contraceptives (OCPs) + GnRHa depot + HRT: Consists of programming the agonist in a controlled cycle with OCPs. Indicated mainly in women with very irregular cycles or ovarian failure but not yet menopausal.
The commercial products used in the preparation and dosages are:
*Most used products
- Depot GnRH agonist:
- *Triptorelin 3 or 3.75 mg intramuscular (IM) Decapeptyl®
- Triptorelin subcutaneously (SC) or IM Gonapeptyl®
- Leuprorelin 3.75 mg IM or SC Enantone®
- Goserelin 3.6 mg SC via Zoladex®
- *1-2 mg Estradiol valerate: Progynova ®, Meriestra ® – Dosage: 6 mg per day orally (3 mg every 12 hours or 2 mg every 6 hours)
- * Estradiol transdermal 75 mcg *: Estradot ®, Estraderm ® – Dosage: 150 mcg (2 patches) subcutaneously every 3 days
- * 100-200 mcg * Micronized Progesterone: Utrogestan ®, Progeffik ® – Dosage: 400 mcg / vaginally 12h
- Progesterone Gel: Crinone 8% ® – Dosage: 1 applicator/12 h
- Intramuscular progesterone – Dosage: 50 mg / 24h IM
- Donor-recipient match: The primary criterion to be considered for the allocation of a donor is the physical traits or phenotype. Following Spanish law, the aim is to try to achieve the greatest possible phenotypic similarity between donor and recipient (race, color of skin, color of hair and eyes …) to facilitate to the utmost, the integration of the future child to his/her environment. Making a match by blood group is not medically relevant; however, whenever possible, we will try to accomplish it. We must also take into account the blood group of the partner in order to know which group or groups are consistent with the partner, and it does not necessarily have to coincide with the blood group of the recipient. Blood groups considered concordant are all those groups that may be possible from a biological point of view after the combination of the two different blood groups.
Last Updated: November 2017