Friday, July 9, 2010

weeks v. months v. trimesters

This topic drives me INSANE. I love numbers. LOVE them. That said, I prefer that numbers match up. In pregnancy, nothing matches up. Seriously. This keeps me up at night. I know many of you will read this and say, "Who cares?" (Or just not read it at all.) But I like numbers. So I care, which means I have a love-hate relationship with the pregnancy countdown.

Let's get started.


A "full term" pregnancy is 40 weeks from your last menstrual cycle, 38 weeks from conception. I prefer to go by the 40-week calendar. Weeks do not cleanly break down into months OR trimesters. Read on.


A "full term" pregnancy (according to 40 weeks) is 9 months-ish. It is more like 9 months and one week. More precisely, 9 months and 5 days depending on the months you are pregnant.

Technically a "month" is from one date to the same date in the next month, right? So if you conceived on, say, the 5th of June, then you are 1 month on the 5th of July. That's 4 weeks and 2 days. Close enough, right? Sure. It's close enough in the beginning, but let me go on.

Here's what drives me crazy. As I pointed out above, one month is NOT 4 weeks. The only month that is 4 weeks is February (3 out of every 4 years). So if you want to say you are 1 month at 4 weeks, fine. You're only 2 days off. But if you want to say you are 5 months at 20 weeks, you are almost 2 weeks off. You are really only 4 1/2 months at that point. If you round off your months to every 4 weeks, then you will be "10 months" pregnant by the time you have your baby. And who wants to be pregnant for 10 months?

Today I am 17 weeks. According to this baby's conception date, I will not be 4 months until this coming Monday, July 12th. 17 weeks, 3 days. Not 16 weeks.

{Can you tell this drives me batty?}


Trimesters are even worse. 12 weeks is not the end of the first trimester (since 12 weeks is not 3 months). 40 weeks divided by 3 is 13.3333. That's 13 weeks and approximately 2 days. This means that the third trimester would start at 26 weeks, 4 days. Sorry to break it to all the 4-week-monthers out there, but the 3rd trimester does not start at 24 weeks. That's not 6 months.

I know it's not nice, but it takes everything in me not to correct people who say they are 6 months pregnant at 24 weeks. 7 months pregnant at 28 weeks. 8 months pregnant at 32 weeks.

Does this bother anyone else? Do I have issues?


The Bundys said...

It drove me batty too. I hated that all the numbers didn't add up and that each time you said something it was really a different measurement. I hated saying months and weeks and all that. I usually just said weeks when people asked or gave the lower number in months or trimesters. Also when I estimated lower or just said lower it seemed like things went faster.

LJ, DC and ML said...

hahahha! And this is exactly why when people asked me how far along I was I always answered "I don't know!" :)

Ella said...

Yes, you have issues! You know how swimmers say 33 laps or 66 lengths is a mile. It isn't technically but it's a swimmer's mile. What's worse is that they tend to call 66 lengths a mile whether they are swimming in a 25 yard OR meter pool. Women aren't saying they've literally been pregnant for 4 months at 16 weeks but they've been pregnant for 4 PREGNANCY months. Get it? Ha. Yes, you give birth at the END of your 9th month. Yes, we will continue to say that every 4 weeks we are one month farther along because that's what books say, that's what doctors say, etc. It's NOT because we can't count. And by the way, don't you know you are considered "pregnant" from the first day of your last period and NOT from the day of conception? When you conceive you are technically about 2 weeks pregnant. It's 40 weeks from LMP not conception. So, now you can drive yourself crazy thinking about that. So, why don't you join the rest of us, and just call yourself 4 months and 1 week pregnant already?! And the next time we're pregnant and every 4 weeks I post that I am one month farther along I hope you don't die from wanting to tell me the truth. Go ahead and tell me, because I won't care, because I think YOU'RE wrong. :)

Erica said...

It totally bothers me too. I completely understand!! lol!

Molly said...

Ha! Ella, I love you! But I will probably always want to correct you. There's no such thing as a pregnancy month!

When you are 10 months and I'm 9 months, I'll tell you that it must really suck to be a month overdue. :)

(And thanks for pointing out my 40 v 38 weeks mistake. I was typing too fast and totally wrote the wrong words down.)

Julianne said...

I have had multiple people try to explain to me that pregnancy is actually 10 months long. What a silly business.

Ashley said...

You know this bugs me too, mostly when people say they are 6 months at 24 weeks because I think they are trying to look skinny for what a real 6 month-er (more like 27-28 weeks) would look like. But I have issues. I assume the general world thinks of pregnancy as 9 months, so I could back from my due date. I'm due Aug. 12th, so right now I'm a few days shy of 8 months. (although weeks-wise I'm 9 months and ready to pop!)

Ashley said...

I meant I COUNT back from my due date. OR I just say how many weeks/months I have left.

LJ, DC and ML said...

HHAHAHAHA Ashley, that's exactly what I thought too! They just want to look skinny, or they feel awful if they were leaning the other direction.

Amy Carter said...

agreed! 4 weeks doesn't equal a month!

i agree that counting back from the due date makes it easiest.

Ella said...

Molly, suit yourself. I think you'd like it over here on my side, though. The numbers crunch really well. And you don't have to consult a calendar when someone asks how far along you are.

Ashley and Lenessa, Now you're just being silly. I didn't realize you're supposed to look a certain way at 24 v. 27 weeks. I would cut your friend some slack and realize she's probably saying 6 months because her doctor told her she's six months, because her book told her she's 6 months, and because in the pregnancy-timeline-made-easy version she is 6 months. Not that she's trying to pull a fast one on you.

Holley Williamson said...

you're so funny, but I totally agree with you. That's why when people say how many months they are, I ask, but how many weeks?

Dana said...

That is the best blog entry!!! I agree, it is so confusing. I hate when people ask me how many months I am, I always respond back in how many weeks I am.

Em said...

Not being a numbers person, I have a feeling I'm one of the idiots in the last paragraph telling people I'm farther along than I really am. But it's only because it's so dang confusing, which is why I love this post. It PROVES how confusing and stupid it all is.

The worst is that anyone who is unfamiliar with pregnancy knows NOTHING about weeks. Telling a man that you're 36 weeks is like telling him that you like the way his tie looks with his pinstripe shirt. Makes no sense to him.

Congratulations, by the way!!! You have the cutest, smiliest little boy, I'm sure No. 2 will be the same.

Bonnie said...

Molly, you're HILARIOUS! I love confusing people by using all the different "amounts" at different times, so they never keep up. So, I voted for Rett Syndrome, and I'm wondering... can you vote more than once a day? Or is it once a day, or once ever? I'm having a hard time keeping up with all the different contests!

Kerri said...

Yep, thought this very thing, and still do! It ALSO gets confusing when you're telling your baby's age and it's "one week" "two weeks", etc. but then you start saying months. When he's 4 weeks old, he's not really 1 month yet, so you don't start changing into months until the "weeks" numbers get to be too much. I still haven't heard someone introduce me to their 48-week old baby.