Романова Ольга Олегівна
Головний лікар клініки, ведучий репродуктолог; основна спеціальність: акушерство і гінекологія.

Oocyte accumulation at low ovarian reserve

The number of eggs for fertilization is one of the major factors in the success of pregnancy in the IVF program. The effectiveness of achieving pregnancy directly depends on the quality and quantity of eggs we received for fertilization and the optimal number is considered to be from 6 to 8 oocytes.
There are situations when even at a young reproductive age the ovarian reserve (stock of eggs) is reduced and for one cycle of stimulation it is not possible to receive more than 1 – 2 eggs.

Reasons for premature decrease in ovarian reserve:

  • ovarian surgery in anamnesis
  • congenital decrease connected with oocyte reserves (usually genetically transmitted)
  • cysts in the ovaries (often endometrial)
  • selected autoimmune diseases (AIT – thyroid disease, rheumatoid arthritis, systemic lupus erythematosus), which may affect the immune system on the ovarian tissue
  • after chemotherapy, radiation therapy and exposure to certain toxic substances.

In this case, additional eggs are to be obtained from several cycles of stimulation, which significantly increases the effectiveness of the infertility treatment program and gives confidence in the success of the reproductive specialist and the woman.

There are situations when it is important for the reproductive specialist and the couple to accumulate oocytes (have more oocytes) for fertilization when carrying monogenic (genetic) diseases in the couple or one of the spouses, and we need more embryos for preimplantation genetic testing (PGT) to find healthy ones (without genetic changes) in order to achieve pregnancy and give birth to a healthy baby.

In this case, we use the program of accumulation of oocytes and their subsequent fertilization.

The successful application of the vitrification method to preserve oocytes has opened up new opportunities for women with a low ovarian reserve to accumulate eggs from several cycles. We obtain oocytes in both the stimulated or natural cycle. As a result, we achieve the number of oocytes obtained for fertilization from 6 to 8. This strategy allows us to reach the same effectiveness of the IVF program as in patients with normal ovarian reserve and response to stimulation.   In such a treatment program, oocyte vitrification is one of the methods of maintaining fertility in women.   The main advantage of oocyte vitrification compared to traditional freezing is that ice crystals which could damage the oocyte are not formed. The survival rate of oocytes after thawing in our clinic is 98 – 99%. The rate of fertilization gives clinical results compared to those with the use of fresh oocytes.

Vitrification of oocytes is a freezing process in which oocytes are treated with cryoprotectants (cryoprotectant) and immersed in liquid nitrogen at a temperature of -196 ° C. Oocytes can be stored for as long as patients need, retaining their ability to fertilize. When we accumulate the required amount, we carry out thawing embryos and commence fertilization.

Benefits of oocyte accumulation  


There is a concentration on the result, which allows a woman with her reproductive specialist to focus first on getting the optimal number of oocytes and also to focus at the stage of fertilization and cultivation. This significantly enhances the effectiveness of the IVF program.


We provide process of fertilization of all accumulated oocytes  simultaneously, that allows patients to optimize expences compared to the phased process of fertilization and cultivation in each cycle. There is payment for full treatment, not for several consecutive cycles.

Delayed embryo transfer 

It has been proved that the efficiency of delayed embryo transfer is much higher than the success rate of pregnancy compared to transfer in the cycle in which applied the stimulation of superovulation. Delayed transfer also promotes the increase the effectiveness of stimulating the growth and maturation of oocytes, use various stimulation schemes (including DuoStim), which are not used in stimulation in a cycle with sequential transfer of the embryo into the uterine cavity.   Thus, the accumulation of oocytes in women with low ovarian reserve is an effective strategy to achieve pregnancy and give the birth to a healthy baby.

However, it is important to discuss this option with a reproductive specialist, who will select the optimal treatment for your particular case.