Donor egg back up, known as Tandem IVF Cycle, is a fertility treatment where both expectant mother’s eggs and donor eggs are used to creating embryos for implantation. In this treatment, both normal IVF treatment and egg donation IVF treatment are performed together.Tandem IVF Cycle is a great option for a woman with highly diminished ovarian reserve to become a mother by using her own eggs while having back up donor eggs to be used in case her own eggs fail.Tandem IVF cycle is preferred by women with low ovarian reserve, who want to receive IVF treatment with their own eggs first but to use donor eggs in case their eggs fail.

Egg retrieval is simultaneously applied to both the expectant mother and the egg donor in Tandem IVF cycle. As a result of egg pick-up process, a large number of eggs can be obtained. This provides the opportunity not to cancel the treatment in case of failing to retrieve egg from the expectant mother or create embryo(s) with the eggs retrieved from the expectant mother. After the embryo transfer, the unused embryos can be stored for future use upon the consent of the expectant mother.

There are several indicators to identify the patients who are suitable for Tandem IVF cycle:

• The patient is not yet in the menopausal age group and continues to menstruate, but is now in the age range posing risk of having low ovarian reserve
• Observing lower ovarian reserve and poor quality eggs via ultrasound
• Finding signs such as elevated follicle-stimulating hormone levels indicating lower ovarian reserve via hormonal analysis
• Encountering lower ovarian reserve during the patient's previous IVF cycles or other ovarian induction treatments

Treatment Process in Tandem Cycle

1. Both the expectant mother and the egg donor, who is selected by taking into account certain criteria, receive fertility medication to help synchronize their menstrual periods. Besides, they both receive medication to stimulate ovaries to produce eggs in appropriate quantity and quality just as in the standard IVF cycle.
2. Since their menstrual periods are synchronized, mature oocytes are retrieved simultaneously from both the expectant mother and the egg donor on the same day.
3. The mature eggs that retrieved from the expectant mother and the donor are fertilized with the sperm, which is collected from the male partner on the day of egg retrieval, via ICSI method in the embryology lab.
4. Embryos obtained after insemination are kept in such a way that they do not mix with each other. The development of the embryos is monitored in the lab.
5. Embryos created using the expectant mother's eggs and embryos created using donor eggs are evaluated separately. On the day of embryo transfer, the expectant mother is informed about the development of embryos created from her own eggs and donor eggs. The expectant mother can choose between donor’s embryos, her own embryos, or a combination of the two. After the embryo transfer, the unused embryos are vitrified and stored for future use upon the consent of the expectant mother.