We collected 12 eggs… so why did we end up with only 2 embryos?

Let’s follow those 12 eggs

Twelve eggs can feel like twelve little possibilities. You hear the number after collection and, without even meaning to, you start holding onto it.

Twelve.

Then the updates begin.

Some eggs are not mature. Some do not fertilise. Some embryos stop developing along the way.

And suddenly, a number that once felt reassuring starts getting smaller.

That can be one of the hardest parts of IVF.

One thing I want you to remember is that the drop does not automatically mean that something has gone wrong. IVF simply allows us to watch, step by step, a biological process that would usually happen quietly inside the body without us ever seeing the numbers.

First: not every egg collected is ready

After egg collection, the embryology team looks at how many of those eggs are actually mature. An egg being collected does not necessarily mean it is ready to be fertilised. So you may hear "12 eggs collected", and then later learn that only 9 are mature.

That can sting.

You had already heard twelve. Twelve had already started to feel like yours.

But those three eggs simply had not reached the stage needed to move forward.

This is the first point where IVF reminds you that the number collected and the number able to continue are not always the same.

Next: not every mature egg will fertilise

Now imagine that 9 of the 12 eggs are mature.

Those 9 move on to fertilisation.

And then comes another update.

Maybe 7 fertilise normally. Again, the number gets smaller.

And when you are the person waiting for that phone call, "9 became 7" feels like two chances disappearing.

A mature egg is ready for fertilisation, but that does not mean fertilisation is guaranteed. There are still several tiny biological steps that have to line up perfectly. Sometimes they do... and others they do not.

Then comes the waiting

Once an egg has fertilised, the waiting really begins.

Over the next few days, the embryo has to keep dividing and developing.

Some do, some slow down and some...stop.

And by this point, every update can feel heavier than the last.

You are not just hearing numbers anymore. You are waiting to find out how many are still growing.

That is why this stage can feel so cruel.

But embryos stopping before the blastocyst stage is not unusual. Not every fertilised egg will have what it needs to keep developing.

And then, maybe, there are two

After all of that, you might end up with two blastocysts.

And I know how easy it is to look back at the original 12 and think, how did we get from there to here?

But those two embryos have already made it through every step before them.

They were mature enough to fertilise, they fertilised normally, they kept dividing, they kept developing... And most importantly they made it to a stage that many embryos never reach.

The numbers can mess with your head

It is almost impossible not to get attached to them.

Twelve feels hopeful. Then it becomes nine. Then seven. Then two.

And somewhere along the way, it can start to feel like you are losing something each time the number changes.

I want you to remember those numbers are not a grade for how well your cycle went!

They are just snapshots of what is happening at each stage.

And sometimes, two embryos are enough to change everything.

The same starting number can tell very different stories

Two people can both collect 12 eggs and still have completely different outcomes.

One might end up with several blastocysts. Another might end up with one or two.

That difference can come down to lots of things: age, egg quality, sperm factors, genetics, and simply how each embryo develops over those first few days.

That is why the number you hear after egg collection can never really tell you what the final number will be.

It is only the beginning.