Posts Tagged ‘2-day’

2-day, 3-day or blast transfer?

Friday, September 25th, 2009

When you do IVF, it is possible to transfer your embryos

  • on Day 2 after egg collection (usually 4-cell embryos),
  • on Day 3 after egg collection (usually 8-cell embryos) or
  • on Day 5 (after the embryos have reached blastocyst stage).

If you have only a small number of embryos and plan to transfer them all, the usual procedure is to put them all back on Day 2 because the uterus is the best possible place for them. However, if you’re doing assisted hatching, you usually need to keep them out for one more day and transfer on Day 3.

If you have a large number of embryos, and particularly if several of them are high grade, you will usually be encouraged to take them all to blast because that turns your ‘longlist’ dilemma (which to choose, which to choose …) into a ‘shortlist’ of embryos that are more likely to be viable.

As any specialist will tell you, odds of a pregnancy with a blastocyst transfer are higher than the odds with a Day 2 or Day 3 embryo transfer. This is an undisputed fact.

Some specialists will also tell you the extreme version of this (which is not actually proven, and is IMHO quite questionable), i.e. that if your embryo doesn’t make it to blast it wouldn’t have been a viable pregnancy anyway.

At virtually all NZ clinics (from what I have heard), the default is to make any leftover embryos go to blastocyst stage before they are frozen. The kicker is that many (and sometimes all) embryos don’t make it as far as blastocyst, i.e. they die in the petrie dish some time between Day 3 and Day 5.

Why does my clinic want us to take our embryos (or leftovers) to blastocyst stage?

The main reasons for these policies (as I understand it) are:

1. For women and couples with a large number of embryos, it is often difficult to tell which are the ‘winners’ that should be put back to give the best odds. By taking them all to blast, only some will make it, and in the ones that do, quality differences will hopefully be more obvious, thereby making the choice easier.

2. There are loads and loads of frozen embies that will never be used and no-one knows what to do with them. Ethical dilemma, and a logistical storage dilemma. Getting people to take their fresh embies to blast, and/or making any leftovers go to blast, cuts those numbers down.

3. More frozen embies means more TERs, which means greater expense for the govt (if you are publicly funded) or greater expense for couples (if you go private) – and more stressful 2wws with lower chances of a BFP each time (compared to a blast transfer). If those embies aren’t going to make it, they think you are better off finding out during the 2ww of your fresh cycle than prolonging the agony and expense. [Personally, I think this is a trade-off each couple needs to consider for themselves; having all frosties tank while you’re in the 2ww makes a VERY stressful time even worse.]

4. They don’t want to give people the “false hope” of thinking that their spares in the freezer are potential children because most of them are not. Quite apart from the points made in #3, above, if you’re an older mum, the months you spend doing TERs that end in BFN are months you are getting older before trying another fresh cycle. [I know some women overseas who cycle and freeze several times before transferring ANY for this reason; if they do get pg on the fresh cycle they will be too old and very low odds by the time they try for a sibling, so they bank several embies up front in the hopes that they might get 2-3 kids out of the lot. I have a friend who banked about a dozen embies at age 43-44, got pg on her last fresh cycle at 44, now is 46 and looking to do TERs, thankfully using embies made at age 43-44, not the near-zero-odds ones she’d produce now (if any).]

5. If you’re transferring blasts it’s easier to talk couples into transferring just one (because of the higher odds) and this reduces the number of twin births, which reduces the burden on the taxpayer, health system, the pregnant mum (twin pgs are sooooo not fun, trust me!), and the parents (possibility of losing one or both is higher, health problems are higher in twins than singletons, the first few months in particular are really really gruelling).

So, what are the main arguments against making your fresh embryos or leftovers going to blast?

The big issue here is, of course, could a potentially viable embryo die in the lab when it would have lived in utero? It’s unlikely but possible, in my view. Here’s why:

1. The number of embies that don’t make it to blast seems to me to be far higher than you’d expect for the age of the woman. Just an observation. This not only raises suspicions for me that viable embies are being lost this way, but in all those cases where there are none left to freeze (so many recently, it’s heartbreaking), it also massively increases the stress when you are in the 2ww and find out that EVERYTHING now hinges on your fresh cycle. Even if the day 3ers aren’t viable, some couples would rather have the psychological comfort of knowing there was another non-zero chance if they get a BFN.

2. There are some absolutely clear cases where people have had babies from embies that any self-respecting embryologist would stake their career on their not making it to blast. Case in point a board buddy of mine who put back four including two 5-cells that were so fragmented they looked like dollops of oatmeal, in her words. The embryologists gave them NO hope of surviving, so she just thought what the heck, put them all back. She’d had 5 failed IVF cycles already and was 35. She got pg with quads including one set of identical twins, so one of those oatmeal dollops turned into a baby (or two!). They are now 6yo, BTW.

3. The research apparently shows that blast pregnancies are more often boys, yet this is not the case with IVF pgs from 3-day transfers. This strikes me as extremely compelling evidence that SOME genetically normal girl embryos for some reason don’t make it in the lab but DO make it in utero.

It’s not an exact science of certainties; it’s a mix of probabilities and possibilities. Each couple is going to weigh these considerations quite differently. A lot depends on the woman’s age, how many cycles and TERs you can do without going broke or insane, how many kids you want eventually (and how you feel about ‘surplus’ embryos once you’ve achieved your quota), how stressful the various scenarios are to YOU, how many eggs you get each time, etc etc. Also, the aforementioned downtime (with the woman getting older) while you try multiple low-odds TERs instead of moving onto another fresh cycle.

The major issue I have with this is that IMHO (and based on reports from women all over the country I have spoken to) clinics in New Zealand consistently fail to consult adequately with patients, particularly on whether leftover embryos are taken to blast. The vast majority of patients are left with the impression that they had no choice in the matter. Frequently, ALL leftover embryos die before making it to blast, and patients are upset and dismayed to find out that they COULD have asked for their leftover embryos to be frozen on Day 3 instead. Here’s a typical comment from an IVF patient:

I had no idea we had the opportunity to freeze embies at day 3. This has NEVER been offered to us. From what we understand they are to be frozen day 5. We unfortunately have never had any to freeze as we’ve waited to day 5 for them to get to blast. I didn’t even know it was possible? I wonder why [my clinic] have never mentioned this?

This situation is especially upsetting if you are on your last IVF cycle and can’t ttc any other way (e.g. because of no tubes or MFI/sperm issues). When you’re standing in those shoes, it can just feel like the clinic has done everything it can to get you off their books (or onto another fresh cycle and more $$ in their coffers). I’m not saying that’s the motivation behind what clinics do; I’m just saying that can be what it feels like for patients who haven’t been offered the opportunity to give genuine informed consent on an important aspect of their treatment.

So, how should we tackle this and make sure we get what we want?

  • Think through these issues ahead of time and discuss them as a couple – there are trade-offs for either choice and there’s no single right answer
  • It may also be useful to ask the clinic lab/embryologists for some concrete data on what % of embryos make it to blast for women your age
  • Discuss the issue with your doctor and state clearly what you want
  • Write on your IVF consent form exactly what you want – make sure the nurse is clear on this too
  • Confirm this with the embryologist when you meet with them (e.g. at egg collection)
  • Confirm this AGAIN with your embryologist when you go in for embryo transfer
  • If you get any resistance from the embryologist, call in your doctor and refer them both to your consent form – INSIST on what you want. It’s your right!