What is IVM? Your Guide to In Vitro Maturation

What is IVM? Your Guide to In Vitro Maturation


It seems there are new acronyms added to the wide world of fertility treatments every day.

First, a quick science lesson.

Our ovaries, at any given moment, have several follicles (cells that house eggs) present in an immature state.

Based on your age, this number can range from millions to thousands to a few.

A natural menstrual cycle involves the growth of a select number of follicles until a single dominant “follicle of the month” matures to release the “egg of the month”.

Naturally, the rest of the follicles recruited in that cycle undergo atresia or death, so that the single dominant follicle can be chosen.

But what if you could shift these growing follicles and give them a chance to grow in the lab?

Welcome to IVM: in vitro maturation.

In this article: 📝

  • What does IVM stand for?
  • Who is IVM recommended for?
  • How is IVM different from IVF?
  • How long does in vitro maturation take?
  • How is IVM done?
  • How much does IVM treatment cost?
  • Does IVM work?

What does IVM stand for?

IVM stands for in vitro maturation.

This fertility treatment procedure involves the collection and in vitro (in the lab) maturation of existing, immature oocytes in the ovary.

This gives the chance to grow multiple mature oocytes in the lab, rather than a single dominant egg that naturally matures in the ovaries every month.

These mature oocytes can be used for IVF, ICSI, or even frozen for future use!

But how can these eggs be grown outside the ovary?

This is where the concept of IVM media comes in.

Naturally, the eggs need the hormones of the menstrual cycle and gonadotropins (the growth hormones) to grow and mature.

To substitute this, IVM media is used to grow these immature eggs in the lab.

These eggs are collected in a nonstimulated cycle.

And once taken out of the ovaries, they have the capacity to resume their cell division, and maturation, and even undergo fertilization.

When was IVM created?

In vitro maturation was first successfully used in humans in 1991.

Practiced for several years since 1935, the first birth after IVM of immature oocytes was reported in 1991 from procedures that took place in 1988 and 1989.

Who is IVM recommended for?

IVM has become an established treatment option for women with PCOS.

Apart from this, the benefits of IVM can also be applied to:

  • People who over-respond to hormonal stimulation during IVF. IVM has mild to no medication involved, making it a suitable and safer choice.
  • People who respond poorly to hormonal stimulation during IVF.
  • In cases of oocyte donation as well, when patients have a higher ovarian reserve. If the number of follicles growing is higher in a cycle due to the dosage of stimulation used in IVF, there is a risk of OHSS (Ovarian hyperstimulation syndrome). With minimal medication in IVM, it can prevent OHSS from occurring.
  • People with hormone-sensitive tumors. IVM can enable taking out the oocytes at any stage of the natural cycle. An ovarian biopsy can also be done to extract the immature oocytes and freeze them. This way, people going through chemotherapy can preserve their fertility by freezing these oocytes and continuing treatment of their primary disease.

How is IVM different from IVF?

IVM differs from IVF in a few key ways, but it’s also important to note that IVM can be a procedure prior to IVF.

IVM is the process where immature oocytes are grown in the lab, matured, and then used for IVF or ICSI.

On the other hand, IVF is where readily matured eggs that are retrieved are used for the cycle.

Some other differences between IVM and IVF include:

Minimal to no hormonal stimulation is involved Mild to moderate hormonal stimulation involved
Can be done at any point in the natural cycle Can be done only after controlled stimulation and trigger for the eggs to mature
Involves longer culture of the eggs in the lab, egg retrieval and fertilization may not happen on the same day Limited culture of the eggs in the lab, egg retrieval, and fertilization occurs on the same day
Reduced to no risk of Ovarian Hyperstimulation Syndrome (OHSS) Risk of OHSS

How long does in vitro maturation take?

The duration of in vitro maturation depends on the state of the eggs retrieved on day 1.

During egg retrieval, the eggs retrieved can be in 3 stages:

  1. Germinal vesicle stage (immature), which may take about 48 hours to mature.
  2. Metaphase I stage (immature), which may take about 24 hours to mature.
  3. Metaphase II stage (mature).

The ideal maturation stage of eggs to be used for fertilization procedures is MII (metaphase 2).

The other immature stages are kept in IVM media and checked at a 24 and 48-hour point for any growth.

Once mature, they are used for fertilization procedures such as IVF or ICSI.

Hence, the entire procedure takes about 2-10 days if the end result is an embryo transfer, and about 2-4 days if the end result is the freezing of the mature eggs.

How is IVM done?

The procedure of IVM is similar to IVF, except there’s an additional process of actually maturing the eggs in the lab.

The steps involved include:

  1. Transvaginal ultrasound to gauge the number of eggs recruited in that month’s natural cycle, in each ovary.
  2. Egg retrieval to aspirate immature and mature follicles that house the eggs.
  3. Segregation of mature and immature eggs in the lab.
  4. Fertilizing the mature eggs while the immature ones stay in IVM media.
  5. As the immature eggs undergo maturation, they are fertilized in the 24-48 hours after the egg retrieval.

How much does IVM treatment cost?

While a typical IVF cycle may cost anywhere from $15,000 to $30,000 in the US and between £3,000 and £4,000 in the UK, an IVM cycle is often cheaper due to the minimal medications used.

In the US, IVM is usually around $3,000 to $5,500, and in the UK, you could be looking at about £1,700 to £3,000.

However, as clinics set their own price lists, patients can pay differing amounts for the same treatment.

Does IVM work?

IVM is said to work best for women with high antral follicle counts (having a large number of immature follicles in the ovary).

It also works best for women with PCOS, and the hormonally sensitive population.

It is estimated that around 400 babies have been born through IVM.

While the number is increasing, and the study group for IVM cases is small for any conclusive evidence, the pregnancy rates per transfer vary between 4-27%.

More studies and conclusive evidence are expected in the years to come.

Ultimately, it’s best to have a chat with your fertility provider about the procedure that works best for you.

While fertility procedures may seem like a “one protocol for all” situation, modifications like IVM could be a viable option.

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