Monday will mark 13 weeks. The time at which I lost the last pregnancy and the farthest I’ve ever gotten in a pregnancy. I’m a little nervous.
--------
I have been meaning for a long time to clear up a post from several months ago. My father, trying to be helpful and using some numbers I gave him from our RE (that Jason and I had a 75% chance of success with no intervention), incorrectly assessed our successive chances. Here is what he wrote:
"Suppose you decide to try 4 more times, in future (Hope you are willing to look that far ahead).
What's the probability of success in at least one of those 4 times?
Probability of first failure = 0.35
Probability of first and second tries failing = 0.35 x 0.35 = 0.1225
Probability of 3 failed attempts = 0.35 x 0.35 x 0.35 = 0.042875
Probability of 4 failed attempts = 0.35 x 0.35 x 0.35 x 0.35 = 0.01500625
The probability of at least one success in those 4 attempts = 1 - 0.01500625 = 0.985"
It seemed a little fishy at the time since, in all my book and blog reading, the statistics definitely did not parse out so optimistically. But I thought, what the hell do I know about probabilities? His math must be right.
Anyway, the human body does not bend to such a straightforward probability model. I was confirmed in my intuition by some materials that Misfits posted after returning from her fabulous trip to Chicago where she met experts who had written books specifically about RPL. One of the books came with the table below, which corrected my father’s assumption that each “event” is independent from the other. In undiagnosed RPL – that is not the case; from occurrence to occurrence, the probability of success does NOT stay the same.
I have also included a seriously shocking graph depicting the estimated survival of human conceptions by gestation. They say that human reproduction is incredibly inefficient, and this graph certainly presents it as such.
Though not quite so optimistic as my father’s calculation, I think the RPL landscape (if the losses are unexplained) still presents a hopeful picture. Happy Thanksgiving.
14 comments:
Right on! You know I heart numbers. I'm going to have to bookmark this link. Horribly inefficient indeed.
I have all great thoughts for this particular week and all the rest from here in out. I know how unnerving the lack of symptoms are, but it's got to be that magical place where women say they start feeling good in a pregnancy!
i wish they showed you what it looks like after 5 losses. I guess they thought the women would sever their own uteruses by this point! I think you are just heading into that wonderful period called "Second trimester" where everything is feeling great. And more power to you for it. I understand the anxiety though. Totally. I wish you the best.
for me, i see any pregnancy of having a 50-50 chance. either it'll stick or it won't. i know the actual odds are better than that for me, but seeing as the odds of me having a miscarriage last time were slim to none, that's not very reassuring.
human reproduction is insanely wasteful and honestly, i'm amazed that anyone ever has a healthy living baby.
Yep, the moment I saw your father's calculations (charming though his effort was) I thought "not independent events". That part has always struck me as a super sucky feature of recurrent loss. But anyway! Monday. Huge milestone. I won't try to talk you out of your anxiety (I mean, I totally would if I thought that would WORK!) but I'm gonna assume you're just all fully placental and whatnot. I mean, it is TIME for you to start feeling better. Lots of good thoughts coming your way.
I love data!!! This is great and I too will bookmark it. Even though these numbers aren't ~99%, I am still very heartened to see that most of them are above 50%.
HUGE congratulations on 13 weeks-- and I'll be so happy for you when you are finally past that last loss benchmark. When is your next appointment?
I am happy see you past 12 wks. I know there is no promise granted to anyone, but you get closer and closer to the end goal. Great news! Happy 2nd trimester.
My RE used the same phrase with me - inefficient reproducers. I can confirm this is true.
ps - I cannot seem to find your email address? I would love to take you up on your offer. Thanks for the kindness.
Mixers: The Artisan is what I have and I have not been able to break it in 6 years of infrequent use. The KitchenAid Professional 600 Series 6-Quart Stand Mixer was what I wanted, but if you are an avid bread maker, that still might not hold up. It seems that the Cuisinart 5.5 is the shiz at the moment. I am sure that what you got will be fine!
No news is bad news in this world, but if not (or if so and our feeble words of comfort could possibly do any good), let us know. Or not. Either way, I'm thinking of you.
hey. i just wondered if you're ok as you haven't updated for ages. i hope all is well.
Have not seen any posts for a couple months. I hope you are well.
Soooo..... where you been??? Come back.
Wonder where you went. I hope you are well.
still hoping you're ok melanie x
Post a Comment