08 December 2009

Pregnancy ≠ Nine Months

You know what really gets my goat? Okay, well, lots of things, but one of them is when someone whines that pregnancy is ten long months, OMG, because they've concluded that 40 weeks divided by four-weeks-in-a-month is ten.

WRONG.

Let’s do the math.

One year = 12 months = 52 weeks.
¼ of a year = 3 months = 13 weeks.
¾ of a year = 9 months = 39 weeks.

Now, gynecologists have perpetrated the myth that pregnancy lasts 40 weeks. But that’s only because they assume that most women don’t know the date of conception, but that most do know the date of the beginning of their last menstrual period (LMP). For convenience, therefore, gynecologists start counting the pregnancy from the date of the LMP. But the date of the LMP is generally understood to be about two weeks prior to the date of conception – two weeks in which one is most definitely NOT pregnant. You aren’t pregnant until you’ve conceived.

So, take the 40 weeks, subtract the two weeks in which you aren’t pregnant, and you get 38 weeks of actual pregnant time. The careful reader will note that 38 weeks is LESS than nine months. Ta da!

26 comments:

Angelina said...

This is just another example of how math is very practical and useful and more of us should use it to get at the truth.

I never paid much attention to how many exact months pregnancy was. It was going to feel long at any length.

Anjali said...

That's always bothered me, too!

Of course, for me, pregnancy has always felt like nine years.

FreshHell said...

Either way, it FELT like 10 months. Sounds like new math to me and I'm suspicious of it. :) *places tin foil on head*

Rima said...

But it Feeeeeeeeeels like ten months!!

kathy a. said...

well, and the length of pregnancy is approximate, and not every baby stays put for the predicted time. "due dates" are kind of guesstimate; who is ever born on a due date?

my daughter [20] hates that i know exactly when she was conceived, on account of EW! ew. eeewwww.... she was born exactly 8 months later -- a month or so "early," but everything worked out fine.

meno said...

By the new math, i am two weeks pregnant! Along with every other woman in the world.

Aunt Becky said...

Math is hard.

Marty, a.k.a. canape said...

Dammit.

I'm 33.5 weeks pregnant. I don't care how many months it is. I would just like for this wonderful miracle of mine to get his ass out of my ribcage for five minutes.

Ahhhhhhhhhh. I feel better now.

ozma said...

Math is hard.

Melissa said...

Mine was born on his due date. And hasn't been on time for anything since...

Carol said...

I'm pretty sure that I've known that a human pregnancy lasts nine months since I WAS a human pregnancy lasting nine months. Doesn't everyone and their dog know this??

I personally have long been amused by the fact that someone "two weeks pregnant" hasn't even conceived yet...

Fresh Mommy said...

Hahaha, that is great. Except for the fact that I'm at 31 weeks, and have always felt like the baby will come earlier than 40 weeks, but I'm also not ready yet!!! Meaning that I've got to get stuff ready! Ahhh.

vodkamom said...

It feels like nine YEARS.


xoxoxox

erin said...

They freaked me out by shooting me up with drugs when Elijah started coming at supposedly 37 weeks...he was born six hours later, despite their medicines, weighing in at 10 pounds 14 ounces bright pink and super healthy.

YourFireAnt said...

Math isn't hard. Demythologizing is hard.

Bibliomama said...

I can't say that's ever gotten my goat. Not even once. My goat has been ungotten by that particular thing. But I was a little bugged by the 'millennium' thing coming up to 2000.

repliderium.com said...

9 or 10 months- it baffles me that some of you can BUILD A HUMAN BEING! Hell, I can barely make coffee some days!

I Am Very Mary said...

Bibliomania cracked my arse up! I was going to come up with some wry & witty commentary, but now? I'll just reread that comment.

mayberry said...

This has always bugged me too. There's only ONE month of the year that is exactly four weeks long.

nonlineargirl said...

AND there is the extra annoyance for anyone who had an IVF-induced pregnancy of knowing one's exact date of conception but still having to use two weeks before then. (and two weeks before then was a maze of shots and tests and there was no period happening then and and and)

Gwen said...

If only I could get pregnant again to test your math accuracy.

Wait.

That came out wrong.

Jenn @ Juggling Life said...

I never even thought about it. I am one of these people that can tell you the when and the where--except for the last surprise.

Kyla said...

But it feels like forever. LOL.

Julie Pippert said...

You crack me up -- love this. Be my Math Queen for always.

But also, then there are those of us who know the day-hour-minute of conception, in which case, our due dates are an exact science, not art, and still, those babies do NOT keep to schedule lol!

Gotta Knit! said...

To funny! I was just explaining this math to my husband the other day when I was trying to explain why due dates are just stabs in the dark to get into the neighborhood of the actual date my friend might deliver.

Jocelyn said...

I like you cranky.

The only thing I pay attention to is that I carried my second kid for 41 days longer than the first one (that's, like 10 weeks!), which resulted in his weighing 50% more than the first one. I've not yet forgiven him for that.