Tuesday, July 20, 2010

Making it Count

Everybody's got their coping mechanisms. Now that Shannon and I are back in the swing of things, trying once again to wrap our heads around the fact that thousands of miles away, in the belly of a virtual stranger, grows the hint of an idea of a family - well, if that isn't a time to cope, I don't know what is. My preferred method is to do poor man's research - Google and Wikipedia - in order to snow myself into believing I understand everything that's going on.

Here's an example of the mess I get myself into.

How long has R been pregnant? Simple enough, right? It's helpful to know this information over the short run as we use that length to determine if the beta numbers are within normal limits. For example, see here. In the long run one uses it to estimate the delivery date. Turns out the answer's not so simple for those of us going through multiple rounds of IVF.

First of all, measurement of pregnancy length (aka gestational age) begins on the date of the carrier's last menstrual period (the LMP). The reasoning is that with natural conception there is no way of knowing when conception actually occurred - all the woman knows is the date of her LMP. We were told R's LMP was June 7. (There's a fact one doesn't typically know about an acquaintance.) This means we've been pregnant 43 days.

Here's the problem. This entire pregnancy length calculation is an estimate based on the assumption that conception occurred two weeks after LMP. If doctors know the exact date of conception then one no longer needs the LMP date. Instead, one measures the length of time from conception (called gestational period) and then adds two weeks to get the length of pregnancy.

We know our conception date. Sort of. The actual marriage of egg and sperm occurred back in February. After two days of wedded bliss, our two unused embryos were put on ice and then thawed four months later for our second attempt. The thawing occurred on June 24 and, a few hours later, on June 25, these two potential lucky ones were implanted. So take your pick. Assume conception happened on either June 25 or (two pre-thaw days earlier) June 23, then backtrack two weeks. This gets us to being either 39 days or 41 days pregnant.

So we know, without a shadow of a doubt, that we're either 39, 41 or 43 days pregnant. :-)

(Why haven't we just asked the doctors, you're wondering. Well it turns out the Drs. have acknowledged that the gestational age listed on R's blood reports are wrong. We haven't received a straight answer so - coping mechanism to the rescue!)

Thanks for hanging in there. And my apologies because this is probably a waste of time. Using these hCG charts is a feel good exercise when the betas are high and a feel bad exercise when betas are low. As we've discussed in earlier entries, the range of "normal" measurements is absolutely huge. So huge that you typically can't even use these numbers to determine if more than one embryo is growing. What matters is how fast the beta count grows from one test to the next. This early on in the pregnancy, we're looking for doubling every two to three days. (So far, so good!)

For what it's worth, we'll be using the length calculated from R's LMP. As of Wednesday, July 20 we're at 43 days, or 6 weeks and 1 day. I think. Let me check those numbers again.....


  1. There's no way of working out exact dates at this stage, there are so many variables. just take your date of pregnancy test as being 4 weeks pregnant. I don't know that all these beta tests add anything to the comfort level of IPs, in Australia (and our clinic in Delhi)you get one beta test and if the level looks good - as yours does - there are no more betas, unless there is an obvious problem like bleeding. I think we get over tested in india, most of it unnecessary, compared to what we would get in our home countries. The agony of waiting for results it just awful, been there done that, many times.

    If you're six weeks you have your big milestone scan - yolk sac, gestational sac and heartbeat. That scan means more than a blood number. Hoping it is all fine for you, I would expect it to be, you have an excellent number to start with. i know it's difficult, but do try to relax and enjoy the fact that you are solidly pregnant and there is no indication to show you won't continue to be. You'll feel a whole lot better as you pass those milestones, promise!

    It's looking great for you guys. Live in the moment and enjoy the miracle that IS happening for you!!!

  2. I think that the ranges are so wide that you can't really specify the actual dates. I think that you should count your conception date as a 2 days before the implantation. I think SI freezes the embryos after 2 days (that was our experience) so if you add another 14 days you have your first day of the last menstrual period.

    Anyway, the numbers are really good, and it's all that matters. YOU ARE REALLY PREGNANT!
    Congratulations, can't wait to hear from you after the first ultrasound.

  3. to calm your nerves a bit, you may want to request an ultrasound for a heartbeat check from your clinic. it should be detectable at 43 days. good luck, hoping you guys get that most magical number of all, 2, the number of thumps in a heartbeat!