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Day ONE (from an embryologists perspective)

When I was working in Rockhampton for #monashivf I had a very close and lovely relationship with most of our clients. I was the only full time member of staff, which meant that I often answered the phone, received the first tentative 'I think we might need some help' type phone calls.... and I got to look after these lovely families right through to when they (often) brought their newborn babies in for me to cuddle (oh those cuddles!!).

I am still connected with a lot of them on Facebook and some of those little embryos are now old enough to have their own Facebook pages!!!

One of the things my patients would often get confused about was the way we count the 'days' in a fertility treatment cycle...

Firstly... day ONE of your cycle is the first day of bleeding, the first day of your period. This is sometimes a sad day when you're trying to conceive, because it means that you have not been successful yet.... (just as an aside.... when you are asked how long your cycle is, it is counted from Day 1 of one cycle, to day 1 of the next cycle - usually somewhere between 25-33 days is considered normal)... So we are used to Day ONE meaning the first day of your period... Once you are under the care of a fertility specialist, and you've had all of your preliminary testing done and you are ready to start a treatment cycle - then Day ONE - your first day of bleeding, is the day you are asked to phone the clinic so that your treatment for that cycle can get started.

You will have already talked to a nurse who will have given you the treatment plan for that cycle and day ONE is when it all gets started.....

Depending on what kind of stimulation you are having (the injections to make the eggs grow) you will have a number of days of injections, a few ultrasounds, maybe some blood tests and eventually arrive at 'pulling the trigger'. The Trigger is the last injection before your egg collection, given 36-38 hours before you are scheduled to be in theatre having your eggs collected... this could be anywhere between day 9 and day 20 of your injections (maybe even more!)

But all of a sudden, as soon as your eggs are collected, people start talking about days again - and that's confusing... your last day ONE involved having a period and you're most definitely not there yet.... no... which leads me to 'Embryologists' Time'

Your egg collection day is, in embryologists' speak:


This is the beginning of your relationship with your embryologist - the scientist who will be looking after your eggs, sperm and embryos until they are ready to be transferred back to your uterus, or stored for future use (vitrified or frozen).

You may or may not get to meet your embryologist, depending on your clinic's procedures, but they're pretty important people (of course I think that!).

On day Z E R O (in lab time) the embryologists are VERY busy.. this is the day the eggs and the sperm get to meet, and we have to make sure everything is as it should be.. so I'm going to go back one day to D A Y: M I N U S O N E

Day M I N U S O N E - preparation day - preparing dishes, tubes, paperwork

Day Z E R O - egg collection day / sperm production day / insemination day (IVF or ICSI)

Day O N E - fertilisation check

Day T W O - embryos should be between 2 - 6 cells, ideally 4 cells

Day T H R E E - embryos should be between 6 - 10 cells, ideally 8

Day F O U R - embryos should be compacting and forming Morula

Day F I V E - embryos should be forming blastocysts / Embryo transfer day / vitrification

Day S I X - last chance saloon

This is one of the older style of incubators - these days most clinics use mini-incubators or time-lapse incubators. But they still need these big ones for tubes full of media

Day MINUS ONE (the day Before your egg collection)

As soon as you are told when to take your trigger and your time for egg collection has been scheduled, your medical notes are sent to the lab. Your egg collection is timed very specifically for 36-38 hours after you take your trigger shot. Timing from here on in is crucial.

Once we have your notes in the lab, the first thing to do is to make sure we have all the correct paperwork and we understand exactly what we are expecting - how many eggs we might get, whether we are growing them to day 2, day 3 or blastocyst, and read up if there is anything else special we need to know.

There is a lot to prepare in the lab - we need to label up ALL of the things we might need for the next day - dishes, tubes, paperwork etc.

In my day, we did this with a 3 code system - a name, a number and a colour (and these days most labs also have a barcode system too). We had special pens that had been tested to be safe for use in an embryology lab and we were really good at writing backwards and upside-down so that names and numbers could be read whilst looking at embryos down the microscope.

There are tubes for the follicular fluid to be flushed into, dishes ready to search for the eggs in and other dishes ready to put the eggs in once we find them. We need to put the right kind of culture media (feeding liquid/solution full of nutrients right for the eggs) into the dishes and tubes and we need to equilibrate them - this is how we make sure that they are at the right temperature and the right pH for the eggs to be safe.

We also need to make up bottles and tubes for the semen sample to be washed and prepared (a topic for another blog post!)

Then we need to make dishes ready for the sperm and eggs to meet. If you are having IVF then the washed and prepared sperm goes into a dish with the eggs and we leave them alone overnight, but if you are having ICSI then we need to prepare a special culture media that is used when the sperm are injected into the individual eggs using the special microscope. This is made up the day before so that it can be at the right temperature and pH, ready for the next day

Day Z E R O

This is YOUR big day - the day of egg collection. You may meet with an embryologist on your way into theatre (we need to make sure that your name band matches with our notes, dishes, tubes and bottles and that we have the right person's eggs going into the right dishes!) and then we sit right there in theatre (or sometimes through a little hatch) and receive the follicular fluid as it is sucked out of the follicles with the egg collection needle.

We search through that fluid searching for eggs and call out as we find them, at this stage, your eggs look a little bit like fluffy clouds as they are surrounded by extra cells that have been supporting them in the follicles in your ovaries. Eggs are covered first by a layer of cells called the corona cells, then by a big halo of cells called Cumulus cells.

Meanwhile, the semen sample arrives in the lab to be cleaned and prepared.

Eggs and Sperm need to meet within 42 hours of your trigger injection.

There are two ways for them to be introduced to each other - Standard IVF or ICSI. Which one you have depends mostly on sperm quality, but also on previous cycles (if you've had them). If you have a male factor infertility (low count, low motility or high numbers of abnormal forms) then you will most likely have ICSI. If you are having IVF for other reasons and your semen sample is within normal ranges, then you may have Standard IVF. In Australia, roughly 70% of IVF cases use ICSI.

If you are having Standard IVF, then the eggs are washed and placed into an insemination dish ready to meet the sperm (after the semen sample is washed and prepared)

If you are having ICSI (see other blog post) then we need to remove, or strip, the corona and cumulus cells from the eggs so we can get a good look at them and work out how many of them are mature enough to be injected (there are a number of different stages of maturity and the eggs will only be receptive to the sperm at certain stages).

After the eggs and sperm have been introduced to each other (either through IVF or ICSI) we then leave them in the incubator and let them do what they need to do.

Then it's time to prepare dishes and media for the next day - labelling everything carefully, double checking and preparing for every eventuality..

(and to be preparing for other patients who will be having their own Day Zero the next day... or the day after... and let's not forget about the ones who are already on day 2,3,4 or 5.. we're looking after them too!)

Which brings us to..

D A Y O N E (again - but this time, no period!)

this is the day we look for signs of fertilisation - there are very specific things we need to see, at very specific time points. 16-18 hours after the sperm and eggs have been introduced, we need to check them for these signs of fertilisation. If we don't see them at this point, then there either hasn't been fertilisation, or there has been abnormal fertilisation.

Any eggs that have been fertilised are then transferred to fresh dishes and fresh culture media and placed in the incubator. In some labs, your embryos are checked again in the afternoon of day one, roughly 24 hours after insemination (insemination is when the sperm and eggs are put together, either standard IVF or ICSI). What the embryologist is looking for at this time is something called syngamy, which is the very first division of the embryo. An embryo that shows signs of syngamy at 24 hours post insemination is definitely one that should be watched closely as it is likely to be the front runner on transfer day!

We then watch your embryos grow and develop for the next few days and depending on your clinic's practices and what is best for you and your embryos, you will have your transfer on day 2,3,5 or 6. (future blog post on Embryo Development)

It's really unusual to have an embryo transfer on day 4... but that's a topic for another post too!

On each day in the embryology lab, the embryologists are freezing embryos, thawing embryos, preparing for egg collections, doing egg collections, inseminating eggs (ICSI or IVF), preparing sperm, checking for fertilisation, checking for cell division and embryo growth and development, scoring, classifying and grading your embryos, choosing embryos for transfer, for freezing/vitrification... if you think about a lab that is doing 10-20 egg collections each day... that's a LOT to keep track of!!


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