Wednesday, 18 September 2013

Numbers and Figures

As we were wrapping our initial REI consult last July, my RE commented, "I think you have a good chance with IVF." "Forty percent" he estimated off the top of his head. I wasn't quite prepared to hear that we would need to consider IVF at that moment, let alone to comprehend that a forty percent success rate would be accepted as 'good'. I couldn't think of any other situation in medicine, or in life for that matter, where a higher failure rate is satisfying. It truly reflects the unique and precarious nature of infertility. "So, that means there is a sixty percent chance that IVF will not work..." I immediately countered. "Well Jane, that depends if you see the glass as being half full or half empty..." He replied, sounding a bit like my mother. "No. That all depends if you are drinking or pouring." I retorted with a saucy tone.

I hadn't intended to be a smart-alec, although it was an added bonus. I did have a point. I've always hated that simplistic test used to determine if one is an optimist or pessimistic, as it entirely depends on the situation. One cannot make an evaluation without any context. A mother who is trying to feed her baby is happy when the bottle is half empty. A pregnant woman taking her glucose challenge test is annoyed when the bottle is half full. A bartender is optimistic when he sees a half empty glass, as it means that the patron may order another. I become irritable if the night is getting late and Husband's pint glass is still half full as I want him to finish up so we can go the fuck home. As it is with so many things in life, it's not black and white.

The 40%-60% split stood out in my mind for another reason. Years ago, when I was talking a colposcopy training course, the instructor referenced a retrospective study from New Zealand. The researchers collected data on women who had high grade lesions on a Pap smear, but failed to comply with the recommended evaluations and treatments. Twenty years later, 40% were eventually diagnosed with cervical cancer. "Isn't it more impressive that 60% did not progress to cervical cancer?" I asked earnestly. The instructor chided that I could not view the results with "Pollyanna thinking." Thus, implying that 40% was still a significant cancer rate, and was irrespective to the fact that 60% did not develop cervical cancer. Maybe it reflects the fact that it's a difficult comparison between infertility and cervical cancer, but on the surface it still seemed odd. In one situation fewer patients gets cancer, but it's still considered bad; in the other, fewer patients get pregnant, but that's considered good? I suppose it helps to frame with ideals and realistic expectations. Ideally, one wants to have a zero percent cancer rate, and I think my instructor was trying to emphasize the role of intervention and treatment in this situation. Ideally, one would like all infertility patients to become pregnant, but unfortunately it's not realistic at this time. Forty percent becomes a significant number when you compare it to the fact that very few patients would be able to conceive without intervention. I also appreciate that 40% is a higher rate compared to couples with more challenging diagnoses.

If we were to take the laize-faire approach to conception, I would estimate our chances for success to be 0.1%. I am somewhat making these numbers up as I go along, with a preference for whole numbers to make my maths easier. I am basing that figure on the fact that even with my Clearblue Monitor, it is still difficult to determine when I will ovulate, and being able to schedule coitus during that time is another obstacle. Perhaps with proactive efforts, our chance of spontaneous conception would be around 1%. Thus IVF increases our chances by 40-400%. It is projected that an IUI only has a 15% opportunity for success in ideal conditions. My RE noted that the sperm count should be between 5-10 million (in the absence of male factor issues, there doesn't seem to be an increase in pregnancy rates when the count is higher than ten million). As we had less than half of the desired sperm count and if you round down a bit to adjust for my old age, we probably had a 4% chance for pregnancy. IVF increases those odds ten-fold.

The diagnosis of infertility really starts to hit home when you approach the data that way. Modest success rates are still preferred to the alternative of doing nothing. It's also helpful to frame your expectations. There is a greater probability that this won't work. It is statistically anticipated that I won't get pregnant with these treatments. Two out of three couples leave their REI clinic heartbroken. I haven't asked my RE to re-estimate our chances for success, and I don't plan to do so. I already know they're probably lower that what he conjectured last year. Just as I dismiss the platitudes proclaiming it will happen! as merely being meaningless words; statistics are only numbers, and they don't necessarily mean anything.


  1. When I had my FET, I asked the RE doing the procedure what he thought our chances were. He hemmed and hawed and threw out, "35%." I remember kicking myself a little because I realized, why ask, he really couldn't know. I mean, that's not completely true, but still. I realize the statistics are all real, but vary greatly between studies and clinics and perspective.

  2. I think it's good that you are going into this with eyes wide open. I had convinced myself during both IVF cycles that I would get pregnant. Sure, the statistics weren't in my favour, but I could come up with a million reasons why I still thought I would get pregnant. I think that made the failures that much harder.

    That being said, one just never knows what will happen. People get pregnant at 40 with their own eggs, and transferring 1 blast, I transferred 6 (over 2 cycles) and I am 27 and got nothin... I guess my point is, we just never know how our cookie is going to crumble.

    I am wishing you all the best, I hope this works for you from the bottom of my heart :)

  3. I like the reference to "The Scientist" again in your title :) And good for you for answering your RE's "glass is half full" remark with a sassy retort! I also hate when people use that expression. Like you said, even wanting the glass to be full or empty is relative, so seeing it as halfway to one or the other can't simply be broken down into "optimism" and "pessimism." I like your analysis of the 40% IVF odds. Another thing to consider is that even the most fertile Myrtle's out there (with their Myrtlepantses in tow) only have a 25% chance of conception on a given month. So with IVF, you are nearly doubling those odds. Another thing to consider is that IVF doesn't have to be a one strike and you're out situation. If a fresh cycle isn't successful, you can always try FETs, depending on how many embryos you end up with. Obviously there's a price tag that comes with that, but I think it's comforting to know you have more options if the first try isn't successful. All things considered, I think your odds look good!

    1. I love that you picked up on my reference to 'The Scientist' -I thought it might be too subtle! Yes, I couldn't resist my snarky comment, although I probably came off sounding like a lush! Good point about normal fertility with Myrtles! I didn't ask if the 40% was cumulative or per cycle, but I guess I'll find out soon!

  4. The researcher in me loves knowing the numbers, but more often than not I end up on the wrong side of them and feel like I'd probably be better off not having ever known them at all. But you're right, they're just numbers, and until you actually start the IVF process you have no way of knowing whether you're going to be one of the ones that gets lucky. I really, really, REALLY hope you are, though.

  5. It always astounds me that the "normal" fertile people have such a low success rate on any given month as well. When you then figure 40% next to their 25% on any given month, it sounds pretty dang good! However, I am with you about going in with realistic expectations. I HAVE to do that in order to not feel so crushed if/when it doesn't work. I am hoping the odds are ever in your favour.

  6. And even when your RE gives you a higher estimated success rate...TRUST ME...many couples still leave heartbroken.
    I just keep telling myself "I'll do (and am doing) the best I can".

  7. its weird. i know the numbers for donor egg IVF; about 66% success. But the truth is, you are either 100% successful or 0% successful. Its not like you get 66% of a baby. so the data is pretty meaningless to the individual. it only applies to the group.