Is there a difference between a round of IVF and cycle of IVF? What does it even mean when someone says “two cycles of IVF”? In this article, IVF veteran Halle Tecco explores the definition. 


By Halle Tecco, MPH

It seems like we’re missing a consensus among patients and providers on the definition of a “round” or “cycle” of IVF.  I would consider myself an IVF veteran, yet I don’t know if I’ve been through five or 13 rounds. Or is it cycles? So I decided to dive in deeper to figure out the real definition of a round of IVF. 

A “cycle of IVF” and a “round of IVF” are synonymous. They are also used to define the number of egg retrievals, regardless of how many eggs are retrieved or embryos transferred. So:

  • If you have an egg retrieval and zero transfers, that’s one cycle of IVF.
  • If you have an egg retrieval and one transfer, that’s one cycle of IVF.
  • If you have an egg retrieval and four transfers, that’s one cycle of IVF.

A “cycle of IVF” and a “round of IVF” are synonymous. 

A round (AKA a cycle) of IVF is pegged to the number of egg retrievals and not the number of transfers. Going through an egg retrieval and zero transfers, or going through an egg retrieval and five transfers, are both considered “one cycle of IVF.” So if the number of cycles of IVF is just how many retrievals you do, why don’t we just call it egg retrievals instead of cycles?

This is probably because for the first 20 or so years of IVF, we were only able to transfer “fresh” embryos three to five days after the retrieval. Now that embryo freezing is pervasive, families are able to create embryos, have them genetically tested, and keep them frozen until they are ready for a transfer. So while you used to only be able to have at most one transfer per retrieval, now with embryo freezing patients are only limited by the number of embryos they can create and freeze for use later.  Simply put, our definition of a “cycle of IVF” has not evolved as fast as IVF technology.

The definition around the world

There are some inconsistencies in the definition around the world, too. A friend of mine in Singapore said they count the number of transfers as the number of cycles. So one egg retrieval with three transfers would be three rounds. But what if it takes you multiple retrievals to get any embryos to transfer? It feels like this would be undercounting the experience for those women. 

And in the UK, it’s only considered a full cycle if a transfer has occurred: “A full cycle of IVF/ICSI has been clearly defined as one in which 1 or 2 embryos are replaced into the womb…with any remaining good-quality embryos frozen for use later.” Which begs the question: what happens if the egg retrieval doesn’t lead to any embryos? Is it not counted as a round? (This might be a good thing since the NHS offers three free cycles to qualified individuals). And also, is ICSI then performed on all cycles? 

I’ve also noticed some people count every IVF-related procedure (retrieval, transfer, ERA) as a round. And honestly, to me, this seems like a better way to calculate the magnitude of going through IVF. We are IVF warriors, and we want credit for every poke and prod! 

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What about frozen embryo transfers (FET)?

So if a round of IVF is just the number of egg retrievals, how do we count the transfers? Most clinics today only do frozen embryo transfers (FET) versus a fresh transfer. This is the part of IVF where a frozen embryo is placed in the womb, french fries are consumed, and all fingers and toes are crossed until you can take that pregnancy test.

Technically, FETs should be counted separately from the number of IVF cycles (AKA retrievals AKA rounds). According to my REI sources, one egg retrieval and four subsequent transfers would be defined as “one round of IVF and four FETs.”

What about a cancelled cycle?

Approximately 10% of cycles are cancelled before the egg retrieval. This generally occurs due to inadequate egg production (84% of cancelled cycles) or hyper-responsiveness (4% of cancelled cycles) and is strongly associated with age. I have had two cancelled cycles due to low follicle count and fibroids. Because this was before the stims started, I don’t count these cancelled cycles as a round of IVF. But what if a cycle is cancelled last minute before the retrieval? Should that be counted as a cycle? The answer isn’t clear. 

My suggestion: a new way to keep IVF score 

If we want a clear and consistent way to describe our IVF journeys, I propose we develop a new way to talk about our experience. Let’s count every retrieval and every transfer that we’ve incurred. We can use the total number, along with parentheses that indicate (retrievals + transfers). So: 

  • If you have an egg retrieval and zero transfers, that’s IVF x 1 (1+0)
  • If you have an egg retrieval and one transfer, that’s one cycle of IVF X 2 (1+1)
  • If you have an egg retrieval and four transfers, that’s one cycle of IVF X 5 (1+4)

Should we count canceled cycles? Endometrial Receptivity Analysis (ERAs)? Donor egg retrievals? Transfers to gestation carriers? These are all part of our emotional and physical journeys, and if you feel like counting them, then you should.

Does it even matter?

Sometimes it feels like we are competing for who is the most infertile, and admittedly, having stats on our infertility can feel a little icky. But, for the new kids in the room, it’s important to help set expectations that IVF is rarely one and done (read more in my article, The IVF Funnel: Understanding Your Chances of Success). And having a universal understanding of what it means when someone says they’ve gone through “12 rounds of IVF” is only helpful. 

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Featured Image by Yaroslava Borz