IVF 14: Game, SET, match

Last night we became preoccupied with the choice of whether to have one or two blastocysts transferred. All along we'd assumed two was the right number, because we felt up to handling twins and wanted the extra safety margin that came along with a "spare."

However, there turn out to be a host of reasons for considering single embryo transfer (SET):
--Multiple pregnancies, even twins, increase the risk factor for all types of prenatal problems: gestational diabetes, pre-eclampsia, etc.

--On average, twins are born at 35 weeks (5 weeks preterm) and weigh 5.5 pounds (2.5 kilos), rather than the 7+ lbs (3.5 k) of singleton babies. Preterm labor and low birthweights place them at greater risk for all types of neonatal problems: cerebral palsy, developmental disorders, digestive problems, etc. (Not to say it always does! Plenty of preemies are just awesome. But the odds are longer.)

--It could even get worse. For unknown reasons, blastocyst transfer during IVF is associated with a higher-than-average rate of identical twins: ~3% of births following single embryo transfer are identical twins. Thus it is not unimaginable that two blastocysts could produce triplets. You don't want to know what the risk factors are for triplets.

--Even in relatively uneventful twin pregnancies, women are often ordered to bed rest for weeks or months to reduce the chance of pre-term labor. I am selfish enough about my career and sanity to want to minimize that possibility.

--A surprising number of studies have now shown that in women under 35, the chance of pregnancy following SET is indistinguishably lower than the chance after two-blast transfer (depending on the study, the numbers are usually something like 59% vs 61%, respectively). Meanwhile, the risk of twins is ~3% and 45%, respectively.

--Due to the sky-high cost of intensive neonatal care for preterm babies, reports suggest that if all good candidates for SET were to select it over two-blastocyst transfer, the increased cost for a second frozen-embryo transfer (if the first one didn't take) would run an extra $100 million--but the savings on neonatal intensive care, due to the reduced number of preemies, would be around $1 billion. And on average, there would be no change in the number of live births.

--For these reasons, the American Society of Reproductive Medicine now officially recommends SET for women who meet the following guidelines: Under age 35; first IVF attempt (or second attempt after successful first); plenty of high quality blastocysts for freezing. Check, check, check.

Europe is way ahead of us on this. Why? Well, patients here usually pay out of pocket for IVF, meaning the cost of an additional frozen embryo transfer (~$3K) is not negligible. Most insurance plans, though, will cover a reasonable portion of neonatal care costs. So patients think with their pocketbooks: why take the risk of having to do this again, if Kaiser will pick up the tab on the other end? In contrast, because IVF is covered in most of Western Europe, couples are more willing to take the chance of needing a second cycle, and so doctors in fact refuse to transfer two blastocysts to women in my category. Europe has noticeably lower rates of multiple births, and accompanying lower rates of neonatal problems. (Learning this has possibly shifted my stance on mandatory insurance coverage for IVF, but I'll talk about that in more detail in another post.)

Meanwhile, the emotional recoil at reducing one's pregnancy chances, however minimally, by transferring one rather than two is hard to understate. We've been working on child production for three years, during none of which have we gotten younger. The holidays are coming up. I want to spend Christmas beaming at Dr Hyde, not crying under a comforter.

Even less nobly, I must admit that I have been so jealous of my fertile friends in the last few years. The thought of twins brings out my competitive streak. Two at once! Top that, all you "on our very first try!" folks. It's embarrassing to write, but it's how I feel.

So we spent last night wavering, angsting, talking, Googling, and thinking. What would be worse: failing to get pregnant on this cycle and blaming ourselves for only transferring one? Or getting pregnant with twins, perhaps forcing me to bed rest, perhaps putting them at greater than average risk for complications, pre-term birth? And what were the relative likelihoods of these events? Impossible to calculate. We went to bed undecided, though Dr H leaned a bit towards SET.

In the morning we met with the embryologist. She had great news for us: we have a total of ten viable blastocysts, with five of them achieving the highest grade they give (4AA).

As straight-A students ourselves, we took this as a given (and thought that perhaps our 3AA and 4BB blasts were not living up to expecations) until she explained that she grades strictly: she rarely sees a 4AA, let alone 5 of them; that 3BB is still above average; and that the majority of embryos they transfer are 4BB or 3BB quality, and the clinic has awesome success rates with those.

I don't mind saying that we preened like peacocks. "Er, could we have a copy of that report card?" Dr Hyde asked.

So we took the plunge and just transferred one 4AA beaut. Will post later about the details of the procedure (no amnesia this time, and Dr Hyde got to watch too), but the gist is that all went smoothly and we are having a restful day at home.

Next Friday is the final exam.