As I mentioned, our plan… assuming we had something left at day 5/6… was do preimplantation genetic screening. Preimplantation genetic screening (or PGS) is testing for overall number chromosomal normalcy. It significantly decreases the risk of miscarriage by screening out the embryos with specific genetic abnormalities of the number of chromosomes that are incompatible with life (and some that theoretically could survive, like Down’s Syndrome). It does not guarantee implantation. It does not eliminate the risk of miscarriage—among other things it does not test for structural abnormality. But if you know you have a chromosomally normal embryo, your chances of success are much higher.
The problem with IVF is that chromosomally abnormal embryos can develop for a while before pooping out. (Part of the reason we wait until 12 weeks into pregnancy to tell people!) For example, one article suggests that “Embryos classified as abnormal on day 3 reached the blastocyst stage at a 40% rate if they were trisomic (having a third copy of a particular chromosome), 21% if polyploid (containing more than 2 sets of chromosomes) and 0% if haploid or monosomic (having one less than the diploid number of chromosomes)—this was true for all chromosomes except for chromosome X or 21.” What this means is that many embryos tested on day 3 and found to be “abnormal” were still growing on day 5 and, without testing, could be implanted only to ultimately fail (or result in a chromosomally abnormal pregnancy). (Source article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169679/)
PGS is different from preimplantation genetic diagnosis (PGD). PGD tests for a speciic genetic condition (like cystic fibrosis).
Eggs / embryos can be biopsied at three stages: (1) egg, (2) day 3 embryo, (3) day 5/6 blastocyst. Egg testing doesn't tell you anything about the health of the embryo. Research has shown that the day 3 testing is not good for embryo development, so it is losing traction. There are many response people might choses to do PGS/PGD, including:
Eggs / embryos can be biopsied at three stages: (1) egg, (2) day 3 embryo, (3) day 5/6 blastocyst. Egg testing doesn't tell you anything about the health of the embryo. Research has shown that the day 3 testing is not good for embryo development, so it is losing traction. There are many response people might choses to do PGS/PGD, including:
- Advanced maternal age (ie 37+) because of the high chance of genetically abnormal eggs (50% of the average 38 year-old’s eggs are abnormal)
- Repeated IVF failure (ie. 3 or more failed attempts)
- Recurrent miscarriages
- Screening for inherited diseases or chromosomal translocations (generally PGD)
Well, we have 2 of 4, and we’re close on a third one. I’m 36 (37 when the baby would be born), 3 failed IVF attempts, and recurrent miscarriages (5!).
Pros of PGS – decreased chance of miscarriage (because genetically abnormal embryos likely to result in miscarriage are not implanted); lower chance of having a child with a chromosomal abnormality (in the general population a 35 year old woman has a 1/164 chance of giving birth to a child with a chromosomal abnormality, that goes to 1/15 for a 45 year old woman); (theoretical) higher implantation rates, which means a single genetically normal embryo can be transferred with a (theoretically) higher success rate than the transfer of an untested single embryo, decreasing the need for multiple embryos to have acceptable success rates and thus decreased chances of multiple pregnancies; potential cost savings because of avoidance of failed IVF attempts
Cons of PGS – possibility that the procedure damages the blastocyst (it sounds like a perfect test of a day 5/6 blastocyst should not damage it, but like anything things are not always perfect); possibility that a genetically good embryo will not survive the thaw (PGS cannot be done in time to do a fresh transfer, a top notch lab should have a 90% survival rate, which means there is the risk that a even healthy embryo will not survive the thaw); potential increased cost (it is necessary to do ICSI [>$1,000] with PGS to avoid the risk that the blastocyst is contaminated with another sperm, and then the actual testing of the embryos [>$2000])
There is an ongoing debate about the value of PGS/PGS. Some argue that the benefits (listed above) mean that it has great value:
Others argue that there is not an increased chance of pregnancy (because there’s nothing about PGS that actually increases the success rate, it just lets you know in advance that there is no point in trying), and there might actually be a decreased chance of success (because the embryo can be damaged):
I think both are right. I would not do PGS because of an “increased” chance of getting pregnant. PGS can’t make bad embryos better. I would do PGS because I don’t want to go through what I went through last year—three failed IVF attempts. I don’t want the heartbreak of having a series of miscarriages. I don’t want to do all of the drugs for no reason. I don’t want to spend money on a series of embryo transfers that will lead to nothing. I don’t want to make it to 20 weeks only to be told the fetus I’ve been trying so hard for has a severe genetic abnormality, and then be thrown into the position of considering whether or not to have an abortion.
We decided that we were generally comfortable with the “risks” of PGS—some chance of damage to the embryo (sounds slim) or failure to survive the thaw—UNLESS we only had one or two blastocysts to test. Before the cycle we decided that if, theoretically, we ended up with only one blastocyst, our reasons for PGS start to fly out the window. I won’t have a series of miscarriages. I won’t “waste money” on multiple rounds of IVF or even spend a lot of money at all—the cost of a transfer is similar to the cost of PGS. And if I only had one blastocyst, I would be a little more worried about even the small risk of damage to it.
So, where did that leave us? We told the clinic that if we had more than 2 day 5/6 blastsys, we wanted to do PGS. But if we only had 1, we thought we would just do one fresh cycle with it.
So we talked to the lab/doctor on day 4. We were told we had EIGHT still growing on day 3, THREE of which were rated PERFECT. (Like 5% of their day 3s are rated perfect, so that’s amazing.) The embryologist told us that was amazing and she expected we’d have a number growing on day 5. So, with that news, we were pretty confident we were going to have enough to do PGS, and emotionally prepared ourselves that we would NOT be doing a fresh transfer. If, however, disaster happened, and we only had one left, we’d be getting an early call on day 5 to schedule us for a fresh day 5 transfer.
Of course the phone rang at 6:18am on day 5. The embryologist said that only one had made it to blastocyst. The good news was that it was a B2, and that five more were still growing. The bad news, of course, was that it was possible none of the ones still growing would make it to blastocyst, so we were in the position of having to decide almost immediately if we wanted to risk biopsy / thaw loss of what could be our only chance of having a baby, or hope that a number of those still growing would make it to blastocyst on day 6 to be biopsied. She said we did still have 5 growing, and maybe one or two would make it to day 6. (She did not sound super optimistic, but said it was definitely possible.) We had an hour—literally—to decide if we wanted to transfer that day or not. (There was no doctor on site at the time, but we were told we could talk to someone—unfortunately, not our main doc—in an hour when we made our decision.)
It was a difficult conversation. Originally my husband took the position that it was our plan to biopsy and we should stay the course. I was worried that if it ended up being our only one and if we biopsied and if it came back normal, but then if it did not survive the thaw, that would be a life-long what-if kind of regret. I reasoned that it really just came down to the cost of a transfer. Because if we put it in and it didn’t work, well at least we tried. And if it did work, boy wouldn’t we be glad we didn’t risk it. And if it worked but then we miscarried, well we’d know that it was a mistake… but I was feeling strong enough to go through one more miscarriage. Maybe it shouldn’t have, but what may have ultimately made my decision was the answer to the last question I asked the embryologist at around 6:25am in the morning. I said, “what would you do if you were me?” She hesitated and then said, “if you’re not afraid to have a miscarriage, I’d put it in today.”
So, we called back a hair before 7:15am and said we were in. Screw PGS, we’re doing a fresh transfer. We were then scheduled for a 9:15 transfer, so things were a little chaotic in our house. (Quick breakfast, clean everyone up as much as we could, chug water, valium, doc’s office.) Our doc’s office does not like having kids in the waiting room, but we did not have time to line-up childcare for the little man. (It can be insensitive to people in the waiting room. I’ve never taken him there before.) We just had him wait outside and when I checked in I explained our situation, so they hurried us back to a waiting room where my husband and toddler could wait without bothering anyone.
When we met with the doctor, it was pretty clear that he thought we should have just waited and done the genetic testing. He explained that while the thaw rate was 85% there, normal embryos tended to that at a higher rate—he spitballed 90%. He said if we wanted to do PGS to avoid a miscarriage, we should not have worried about the number of embryos we had to test. (Not sure I agree with that.) We had some second thoughts, but decided to just go for it.
SO, as I suggested yesterday, sometimes the best laid plans can go awry at the last minute. We were not planning on doing a transfer when we woke up Saturday morning, but by 10am that morning I was laying down in the transfer after what might be our last chance for a kid was floating around somewhere in my uterus.
Anyway, here are some articles on genetic testing:
http://www.advancedfertility.com/pgs-ivf-genetic-testing.htm - general information on PGS
http://www.medscape.com/viewarticle/766626_2 - PGS does not have a negative impact on children born from the testing.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169679/ - PGS may not even increase implantation rate (not good!), although that appeared to be when day 2/3 were tested, not day 5, and in less quality labs
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