In Vitro Maturation Culture(IVM) Guidance

Sumiyoshi Ginza

As for In Vitro Fertilization and micro-insemination, it will be usually done on the mature oocytes, but in rare cases, it can only be done on the oocytes that are not yet mature.
Immature eggs are hardly fertilized even if in vitro fertilization or micro-insemination are performed, so in vitro maturation culture (IVM) is performed.

egg
egg

What is this In Vitro Maturation Culture(IVM) ? circle

In vitro maturation culture (IVM) case circle

Ovum undergoing IVM circle

About “Rescue IVM” circle

What is this In Vitro Maturation Culture （IVM） ？

about IVM
  • A method of allowing the maturation to occur In Vitro by culturing it for 1-2 days using a special culture serum with added hormones.
  • Even when IVM is done and there are some rare oocytes not fertilized.
  • As for the developmental potential and fertilization potential of the matured oocytes by IVM, it is the same as the ones matured in the body.
  • When confirming the maturation, ICSI(Intra Cytoplasmic Sperm Injection) will be required because the granulose cells covering the oocyte will detach.
    (For the oocytes with granulose cells not attached, generally, they can’t be fertilized by In Vitro Fertilization)
  • Since ICSI will be performed at the time when the oocyte has matured, it is necessary that the sperm is collected again or cryopreserved.
  • Oocytes are matured, fertilized and divided by IVM will be cryopreserved and then later in the menstrual cycle, thawed and the embryo will be transferred.
    (Since the endometrium and the oocytes have different age in days, there cannot be an embryo transplant in the period of the oocyte pick-up)
  • The cost of the IVM, regardless of the number of times is ¥100,000.
  • In the case of egg freezing, the eggs are frozen at maturity.
    The number of frozen units may increase depending on the timing of maturation.

*¥45,000 is needed to cancel.
*The price including tax is an estimate stated due to obligation to display the total amount.
Minor differences in calculation may occur at time of actual accounting.

In the following cases an IVM will be done

  • When maturation does not occur even after ovulation stimulants were used.
  • In order to avoid ovarian hyper-stimulation syndrome caused by an overreaction to the fertility drugs, when there is no choice but to harvest the oocytes while they are still immature.
  • When the oocytes were mostly immature as a result of the maturation of oocytes is not in accordance to the size of the follicle(bag the oocyte is in) even though the oocyte has become large enough.
  • When at the same time the mature oocytes were collected, there were many immature oocytes.

Oocytes that actually had IVM

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The body of the oocyte itself is small, and the surrounding granulose cell is in a condition of being small and hard.
The pink color you are seeing is the culture serum of IVM.
As for premature oocytes, even if they undergo micro-insemination they do not fertilize.

We have 2 times the chromosomes(4n=92) of normal somatic cells.
As for the mature oocytes, from the meiotic division becomes a chromosome number that is decreased by half(2n=46)

IVM（24-48hours） ;Restart of Meiotic Division Restart of Meiotic Division

egg

The oocytes matured by IVM.
The granulose cell has softened and spreading out, and if we look at the oocyte itself, the polar body has been released which is a sign of maturation.
Matured oocytes have the same fertilization potential as oocytes that are matured within the body.
This is the mature oocyte that the oocyte reached in second meiotic metaphase.
With the division of the nucleus, there will be an excess number of chromosomes released from outside the cell.The released chromosomes are known as the first polar body and is a sign of maturation.

# # Fertilization

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With the entry of sperm the meiosis will complete, the “Second Polar Body” will be released and it will become a fertilized oocyte.

Rescue IVM

This is a method of in vitro maturation of immature eggs that cannot be fertilized at the stage of microinsemination.
The retrieved eggs are not necessarily mature eggs, and there are cases where they are immature eggs or mixed.

Since immature eggs cannot be fertilized, they were not used for fertility treatment and were discarded.
If enough mature oocytes have been retrieved, there is an option to discard the immature oocytes.
However, depending on the patient, there are times when sufficient mature oocytes cannot be retrieved and only immature oocytes continue to be produced.

With the desire to do something for such patients, we researched and developed a unique culture method for maturing immature eggs outside the body, and obtained the first government approval in June 2019.
As a result, it is now possible to mature and fertilize immature oocytes, which had been discarded due to lack of fertilization ability, to implant embryos, and to achieve pregnancy and childbirth.
It is also true that the average discus reach rate is inferior to the average for oocytes matured in the body.
We are continuing to work on this to improve rescue IVM performance.

The eggs used for in vitro fertilization are stimulated with a drug to mature the immature eggs in the ovary before being collected.

From Oak Clinic infertility blog