Some IVF clinics copy our services, texts, presentations and arrange seminars in the same locations. Please be attentive to which seminar you register and which clinic you land in. Dr. Olga Zaytseff and her team runs own clinic O.L.G.A. in St. Petersburg and does not work for any other clinics. Lectures at our seminars are personally done by Dr. Olga Zaytseff

Blastocyst culture

Prolonging the cultivation of an embryo is a method whereby we are able to acquire additional information concerning the vitality of embryos in fertility treatments. Prolonged cultivation can be used in both IVF and ICSI treatments. It does not alter hormone stimulation.

During treatment, the embryos are usually cultivated 2–3 days after fertilization. The embryos have divided into 2–8 cells by the time they are implanted into the uterus. At this point, choosing the most robust embryos to be implanted may be difficult because there may be many good quality embryos. By cultivating the embryos a bit longer, we are able to select the most robust embryos that continue dividing and developing.

The embryos are cultivated 4–5 days before being implanted into the uterus. At this stage, the embryo has more than 100 cells and it is in either the morula or blastula phase. This corresponds to the stage of development in a natural pregnancy as it makes its way to the uterus. At the morula stage, the embryo is a cluster of cells that can no longer be precisely counted. At the blastula stage, the cells' first phase of differentiation has occurred. The tissues of the fetus develop from formed tissue mass in the inner cell and the tissue of its placenta develops from the cell tissue surrounding it. At the blastula stage of development, the embryo is ready to attach itself to the wall of the uterus after first having hatched from the zona. The probability that an embryo, which has reached this stage, will attach to the uterus is significant. For this reason, implanting just one embryo is easier, reducing the risk of a multi-fetal pregnancy.

Prolonging the cultivation of an embryo is a feasible alternative in cases where the embryo has not attached to the uterus in previous treatments. One disadvantage to prolonged cultivation is that only about 40–60% of the embryos develop into blastula and it is possible that all embryos cease to develop in which case an embryo implant is no longer possible.

“Three times I went to Russia to pick up some eggs. Six embryos tested by PGS and one was good ))) This little embryo was born when I was 44 and the egg they used was from me when I was 43…”


"...If I would have known at the start, what I know now, I would not have done my IVF-attempts at my age as egg donation gave us result straight away. It was the best decision of our lives!"

Karin and Pedro, Sweden

After 3 IVF in Sweden, 3 miscarriages, Elisabet and Pär became parents of lovely Ester through egg donation in St. Petersburg

Having questions? Ask our doctors now!

A blog by Tone Bråten

A blog — to help you on your journey to become parents!

Our patients tell their stories

    The Egg Solution
    Aftenposten, 27 September 2019, Norway. Miriam Lund Knapstad, Helle Aarnes
    Olga is the miracle doctor who gives baby guarantee, Sweden. 6 August 2019. Text & Malin Aunsbjerg
    Cilla Holm became a mother on her own – this is her new Liv (life)
    Dagens Nyheter, Sweden. 7 May 2019
    Russian baby guarantee is the Swedes’ last chance
    Svenska Dagbladet, Sweden. 7 April 2019
    Mum through embryo donation
    Marie Granmar is my very dear patient from more than 8 years ago. Please listen to Marie’s interview on TV4 7 March 2019 in Sweden
    "I became pregnant with an embryo adoption”
    One more story about our dear patient Cilla Holm by Tara Magazine, Sweden
    Titiyo became this year's Comeback Mum: "I've broken the norm"
    Monika and André pay 240,000 SEK for having a child
    "Had to travel abroad to get pregnant after 8 IVF attempts in Norway"
    Interview with our patient Elin Renate by TV2 Norway
    Report on us on Norwegian Television TV 2
    Enjoy our dear patient Cilla's story, who has been interviewed by the "Dagens Nyheter", daily newspaper in Sweden
    Report on us and our dear patient Hillevi on SVTPlay & SVTNews