Old habits die hard

As you may recall from my last post, the current plan is IVF homework this month; stims and ER next month; detox in July; and FET in August. Not wanting to waste a single egg (what if it’s my only good one left?!), I naturally asked Dr. Y for permission to try ‘the old-fashioned way’ this month. Ever the gentleman, Dr. Y refrained from sharing his thoughts (Why not just enjoy the break? Don’t you realize how low your chance of success is?), and he politely said that would be fine.

So I pulled my BBT thermometer, pen, and a blank chart out of the nightstand drawer, and dug around in the bathroom cupboard for my ClearBlue Fertility Monitor and a stash of test sticks. (Okay, so I may have used the phrase ‘the old-fashioned way’ a tad liberally…) I had skipped all this during our IUI cycle thinking it would be a relief not to have to trouble myself with the morning routine, but I actually ended up regretting it. Throughout the cycle I found myself missing all that precious data! I wanted answers:

  • Would the Menopur injections cause a ‘peak’ reading on the monitor?
  • What about the hCG trigger shot?
  • How long after the trigger shot did my BBT rise?
  • Did the progesterone suppositories cause a higher BBT than usual?

I don’t know! And that bugs me a little bit.

Anyway, I’m back to collecting my precious data this month (and probably will through IVF too, because, why not?!)

And to everyone who wondered how the ClearBlue Fertility Monitor works, the rest of this post is for you. (Wait, nobody is wondering that? In that case, read this hilarious post by Stupid Stork instead…)

Still here?

So, the ClearBlue Fertility Monitor…

Like OPKs, the ClearBlue Fertility Monitor (or CBFM for short) monitors the levels of hormone in my urine. While OPKs detect luteinizing hormone (LH) that surges 24-48 hours prior to ovulation, CBFM detects both LH and estradiol (E2). E2 rises a bit sooner, and a bit more gradually than LH, which means the CBFM can give me more advance warning before ovulation. (This makes it easier to have some semblance of romance in this whole TTC thing. I can say ‘It’s been awhile since we’ve gone out; let’s make Wednesday a date night,” instead of “Wake up! Sexytime! Now! NOW!”)

Each morning starting on CD6, I POAS, cap the little stick, and snap it into the appropriate slot on the monitor. The monitor waits 3 minutes for the stick to develop and then shines a little red light on the stick ‘reading’ the result. For the scientists reading this, I assume the monitor works like a visible absorbance spectrophotometer; I’m looking forward to taking it apart to investigate once I’m sure I don’t need it anymore…

Anyway, after reading the stick, the monitor displays one of three possibilities:

  • Low: low E2 and LH levels. You can have sex today for fun or romance, but you can’t in good conscience use TTC as an excuse.
  • High: high E2 but low LH levels. You can use TTC as a pretty good excuse to have sex today.
  • Peak: LH surge. Ovulation is imminent. Sex today is pretty much required.

The sticks (which you have to purchase separately) look a lot like OPK sticks. But there’s no ‘control’ line – just one line for E2 and one for LH. And the color changes (particularly the E2 color change) are definitely more subtle than for OPKs – hence the need for the monitor to read the result.

I tried, unsuccessfully, to figure out the chemistry (or biochemistry) behind how CBFM works. I imagine that the LH line works using antibodies in a way similar to what I described in this post about how HPTs work, but I don’t know for sure. The mechanism for detecting E2 has to be somewhat different since (a) it’s not a protein hormone, and (b) the E2 line gets lighter as E2 levels increase, instead of darker.

Anyway, here’s a figure showing my monitor & corresponding test sticks for each possible fertility reading:

Image

Note the cute little egg symbol on the display for ‘peak’ fertility.

I color coded the hormone labels in the figure above to match this diagram I found on the interwebs showing how the menstrual hormones rise and fall at varying stages in a cycle. Note the gradual estradiol rise (blue), peaking a day or two before the LH surge (green):

Image

Incidentally, while doing a Google image search for LH and estradiol levels, I found the coffee mug above right, which I would want…except that I don’t think I’m gutsy enough to use it in public. They also sell a hat…

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