Monday, December 20, 2010

Pet peeve: how long pregnancy ACTUALLY is

Yesterday marked exactly one month until my due date. Which means that technically when people ask when I'm due, I could say, "The 19th," and not need to qualify it with a month, because it's the NEXT 19th. Yikes! I think I'm going to keep saying "next month" until we actually get to January, though. But still. Less than a month away.

Speaking of pregnancy months, here is a pet peeve of mine: it feels like every pregnant woman I know complains that nobody ever told her that pregnancy is actually TEN months long, not nine (which, given that everybody seems to complain about this, makes it surprising that they all seem so shocked by this apparent revelation, since you would think they would have heard each other complaining about it in the past).

But my real issue is this: pregnancy is NOT ten months long. It's not really even quite nine months long. Let me break this down for you. Those of you who have been pregnant before likely know this, but I didn't know some of it until I myself got pregnant, so let's start at the beginning.

Pregnancy is measured as being 40 weeks long. As in, when you hit 40 weeks, that is your due date. BUT, the 40 weeks are counted from the date of your last menstrual period, NOT from the date of ovulation or conception (and those can actually happen a day or so apart as well). Most women ovulate at least two weeks after the first day of their period. So for those first two weeks of "pregnancy," you are NOT actually pregnant. You are only considered to have been pregnant retroactively, but during those first two weeks you could easily have avoided getting pregnant, by using birth control or not having sex (or not going through fertility procedures, and so on--the point is, during those two weeks, the pregnancy was not a foregone conclusion).

Got it? For the first two of the 40 weeks, you were NOT pregnant, even though that time is counted as part of your pregnancy.

So for one thing, pregnancy is actually only 38 weeks from conception to due date. Though sometimes it pushes closer to 40 weeks again if the baby comes late.

But let's just say, for a second, that pregnancy really is exactly 40 weeks long. THAT IS STILL NOT TEN MONTHS. That is approximately ten LUNAR months, but we DO NOT COUNT TIME IN LUNAR MONTHS. If we did, we would say that a year is 13 months long, but we don't. We say it is 12 months long, because that's what our calendars say--all of our months except February are longer than four weeks.

To be exact, a 30-day month is 4.29 weeks long, and a 31-day month is 4.43 weeks long. Let's average those out and round down a tad to account for February (or we could divide 365 by 12, and then divide that by 7, which would give us the same result) and say that a month is, on average, 4.35 weeks long.

So, if we count pregnancy as 40 weeks and a month as 4.35 weeks, that would make pregnancy about 9.2 months long. And if we count the actual time that you are pregnant, assuming an on-time delivery, as 38 weeks, that makes pregnancy about 8.7 months long. NOT EVEN NINE MONTHS.

In case your eyes crossed when I started using decimal points, I charted my cycle the month I got pregnant, so I have exact dates that I can use to demonstrate this more concretely:

My last period started on April 13. I ovulated on April 26. My due date is January 19 (though some calculators/wheels list it as January 18, which I think is actually more accurate--but is not what's in my chart). So, let's see. April 13 to January 19? NOT ten months. April 26 to January 19? DEFINITELY not ten months.

I KNOW, the point pregnant women are trying to make is that pregnancy is long and often feels even longer, but it drives me NUTS when they try to express this by talking about how it is ten months long. IT IS NOT TEN MONTHS LONG.

Nine months is long enough that we all have PLENTY of legs to stand on when it comes to complaining about the misery of the experience. Let's not all undermine our credibility by exaggerating just to make our plights sound THAT much more dire.


  1. I agree with you- it's not ten months. But I *Do* understand the temptation to round up when one is estimating how pregnant one is. Like, 28 weeks is not seven months, clearly. But when you feel like you've been pregnant forever, it is SORELY TEMPTING to round up when someone asks how far along you are and say "seven months." I don't- I say "6 and change"- but I wish I could, sometimes.

  2. ha, you must have been reading the Girlfriend's Guide to Pregnancy, which refers to "nine(ten) months" constantly...

    people are just lazy and don't like doing math - perhaps we should switch to the lunar calendar to really make it simple. Then the 4 weeks in a month thing would work out for people and they would never need to look at decimal points again :-)

  3. I love how precise this is! I started focusing on days remaining for my own sanity, but when someone asks me how many months I am, I get flustered for .5 seconds while I do the math switcheroo. Still, going into the final month of pregnancy makes April seem SO LONG AGO!

  4. This has always been a pet peeve of mine as well! Without looking at charts or anything else, I've always used the formula of last period+nine months+7 days, which would have you at January 20. If a woman conceived exactly 2 weeks after her period began, then we could say conception+nine in the end, it's pretty easy to see that most women are actually pregnant for around 9 months, less a week. The End.

  5. Hahahahaha... Love it! My pet peeve as well.

    Don't get me started on people who talk about "giving it 200%" and other mathematical impossibilities.

  6. Word. This annoys me too! I also like to add in that you don't actually find out you're pregnant until you have been officially pregnant (ie date of conception note lmp) for two weeks. And for those two weeks you don't feel many symptoms. So really, you are only aware of pregnancy for a little over eight months (which does still feel like an eternity by the end, yes).

  7. LOLOL

    My kids were all "late" so I think my pregnancies all lasted forever.

    Including first child who was 3 weeks later than the ultrasound dates and four weeks later than the possible conception. (Yes, he was late to everything else)

  8. Oh, oh YES.

    Whenever someone says pregnancy isn't really nine months, I reply that it's nine calendar months. Having been pregnant into my 41st week, both times I've earned the right to complain, but never have I said that I was ten months pregnant.

    Also, it kind of annoys me when people say that they're x number of months pregnant by dividing the number of weeks pregnant by four. Like, 20 weeks pregnant is NOT five months pregnant. It's four and a half. I just went by the date of my due date, so on the 31st, or whatever, I was then another month pregnant.

    Whatever. You said it better.

  9. I love this! Though, I will say that the weeks to months conversion is often confusing for people. When you are 24 weeks pregnant, you aren't really considered 6 months pregnant. It's all very confusing. But yes, pregnancy is 9 months...and that first month you aren't even aware of it...unless of course you are going through fertility treatments and find out you are pregnant WAY before your missed period!

  10. Yes, YES. There are even BOOKS that have been PUBLISHED with the "ten months" thing in it. I'm always like, "52 minus 40 is 12 weeks, and 12 weeks is not 2 months!!!" Then I fall to the floor, frothing at the mouth with frustration.

  11. Amen! 52/4 is 13!!! There are not 13 months in a year! People are idiots!

  12. It sure feels like 10 months. And I had a baby at 32 weeks, so I don't even know what the very end of pregnancy feels like, but I can tell you that at 32 weeks of pregnancy I felt like I'd been pregnant for a year. :)

    The weeks/months thing has been a hard conversion for us. Since she was a preemie, everything was originally done by her gestational age, which went in weeks. Then when she went home from the hospital and hit her due date, the pediatrician starts talking in months. Which didn't really reconcile with the weeks I was counting in my head. I finally just had to say "OK, they don't match, we're going with months based on the day she was born each month, cause that's what everyone else does."

  13. Not really understanding, but I Been trying to figure out when I conceived and when my last period was as I don't remember. Anyone can help me figure it out :) I had my son on 27th April, due date 30th April , so when would I have conceived my baby or when would my last period have been? Sorry to sound dumb lol

  14. Yesterday marked exactly one month until my due date. Which means that technically when people ask when I'm due.