Monday, December 24, 2007

'Tis the Season

But I can't figure out for what - whether it's a good time to blog, since so few people are that it makes my newly-updated blog more appealing or to take a blogging-vacation (since hardly anyone's around to read blogs, as is clearly obvious from the relative lack of comments about the results of Kirby's cancelled IUI... well, that and my stats, which are basically in the toilet.)

As I mentioned in a previous post, I spent last month reading journal articles about eSET - elective Single Embryo Transfer - when couples have more than one good embryo available, but choose to transfer only one. It's fairly obvious that this is the trend of the future, since pregnancies with multiples are far riskier than singleton pregnancies. It also isn't surprising that deciding on eSET is really hard*, especially for women. Not only is there a sense that the pregnancy rate is lower (per cycle, it is, but if you transfer one embryo one cycle and then thaw and transfer another the following cycle, the pregnancy rates are similar- at least according to one team of researchers**) but it pretty much eliminates the chance of having twins. A survey done among IVF mothers who had already conceived found that mothers with twins perferred twins, but also that 62% of mothers with singletons would have preferred to have twins.***

I'm sure I've said this before, but even after knowing all the risks (which I didn't when I chose to transfer 4 embryos) I still think I would have found myself in the group that was unable to make the decision to transfer a single embryo - if you're going to finally achieve pregnancy, a pregnancy that might be your only one, it almost makes sense to 'try for' twins...

Funding is a partial solution - couples who know they'll be able to have treatment toward an additional pregnancy are more likely to agree to transfer a single embryo. This, apparently, is a good economic choice, since pregnancy with multiples and then multiples are prone to increased health risks, which are a burden to the health system - meaning that long-term it will be cheaper to finance additional IVF cycles than let the current twin rate of 20-25% continue. I believe Finland is one of the first countries to make this decision, but other countries have begun or are at least talking about it. In Finland, the multiple pregnancy rates dropped from 25% to 7.5% between 1997 and 2001 (when eSET increased from about 11 to 56%)**** The overall pregnancy rate per oocyte retrieval was almost unchanged.

One last (and totally subjective) thing I'll mention is that from reading many infertility blogs, it seems that the successful freeze-thaw rate in the US is terrible. It appears that relatively few embryos are frozen and that not enough survive the thaw. Having had lousy embryos frozen and thawed in 1995, when there were only 4 excess embryos, all were frozen and all survived the thaw, I wonder if improving the methods used in the US (or perhaps just being less strict about what embryos clinics freeze) might result in higher FET pregnancy rates. (My FET resulted in my 11-1/2 year old twins.)

*Blennborn et al. (2005)
**Thurin et al. (2004)
*** Pinborg et al. (2003)
****Tiitinen et al (2003)

Ah, and to all those celebrating, Merry Christmas & a Happy New Year :-)
Need some tips on surviving the holidays? (Not an ad, just an article I posted in the past.)


Bea said...

I commented over at Kirby's blog last time.

As for eSET - I remain a big fan. For us, it was a matter of stepping back and asking how we'd feel about our decision in 5 years, 10 years etc. The decision to go safe was an easy one from that point of view.

But of the first half of the batch, we had couple of embryos that only technically survived the thaw (so two SETs and two DETs, as in the second instance the other option was discarding or doing a near-hopeless cycle) and then the last half of the batch were frozen in pairs due to quality issues (so we agreed to thaw the pair and see what we had on the day - both survived).

We reasoned that a SET was logical for our latest transfer, too, with DETs to follow if it didn't work, but we were getting nearer to the end of our tether so transferred two. Well, initially we had twins, but now a singleton.

All going well, I would like to go back to SETs for our remaining embryos.

The funding helps a lot. We would not have held out so long without it. The Australian government has also achieved a great reduction in twin rates simply by funding unlimited IVF.

We are also in the slightly unusual position of having great fertility coverage (in Oz) but poor obstetrical coverage (in S'pore). So it makes financial sense for us to aim for a singleton.

The single/double embryo transfer dilemma is an excellent argument for making the person who funds maternity/obstetrics also fund fertility treatment. Otherwise you don't get an economic solution.


Bea said...

P.S. We had age and prognosis on our side, too.

Thalia said...

Interestingly, an article in fertility and sterility that I read ages ago showed that the funding issue DID NOT have an effect on whether people (study was done in the US) chose SET or not. The thing that had an effect was getting graphic about the risks of gestating multiples. MOst people really underestimate that in advance, but once they are educated are much more likely to chose SETs.