Why do some people describe pregnancy as lasting ten months?

[Overthemoun]

I have seen this a few times recently and I do not understand the thinking. Average is 40 weeks. 52 weeks in a year. 52/12=4.333. 40/4.333=9.231

Also, whilst they count your pregnancy as from your last period, it’s much more like 38 weeks.

Do the people in 10 month pregnancy have 13 month years?

I think you need to look up what average means.

Which you would round down to 4 if doing a rough calculation. I'm only explaining to the OP what she asked

I went to 42 weeks and it was more like 10 years of pregnancy, felt that way anyway.

No, they are 4 weeks and a few days on average I think.

I have never heard a single person say this! Didn’t you ask them why they thought that?

Well this makes me very worried about the state of our schools then.

Sorry, I don’t know who that is! Genuinely never, ever heard anyone talk about pregnancy being anything over than 9 months.

Maybe you're talking to horses...

Several calendar systems do have 13 months, but I don't think nearly any people in the UK who say pregnancy lasts 10 months are using one of those as the reason.

I would have thought that as pregnancy would typically be 9 and a bit months that some just rounded up, if only because of how long it feels at the end. I've never asked though.

Some cultures say 10 because of lunar months. A woman's cycle isn't a calendar month, it's average 28 days.

28 x 10 = 280
280 / 7 days = 40 weeks

The modern western calendar we use now has a whole long history of faffing with it and stealing days off February and the Church arguing about it. Whereas women before that existed would've wanted to estimate a pregnancy. 10 moons would've been a decent yardstick.

I have only ever heard pregnancy described as 9 months personally. But my own pregnancy was actually closer to 10 months because dd was so late.

<weeps>

Yes you can. Solidarity sister.

No it doesn't, by any standards of averages.

The mean average is 30.4 days. The median average is 30. The mode average is 31. None of those are four weeks.

Four weeks is 28 days. Only one month has 28 days, and only three years out four, as every fourth year it has 29. Four weeks is a lone outlier, not the average.

You’ve just described accounting periods though - not months.

A month is either 28, 29, 30 or 31 days long.

My work has 13 4 week periods in a year, but it doesn’t mean there are 13 months.

No Gregorian month has 5 weeks in any scenario (despite PP’s comment that some months “obviously” have 5 weeks). Most other calendars have even shorter months as they’re lunar based.

Spare a thought for the elephant, whose gestation period can be up to 22 months.

The only 4 week month is February. All the rest are 4 weeks and 2 or 3 days

I mean if you find out you’re pregnant in June, are pregnant enough to feel sick at the beginning of July, and don’t give birth until April, by a finger count you will have very much experienced a full 10 calendar months of pregnancy!

People have been talking about pregnancy as 40 weeks since at least the early fourteenth century (that's off the top of my head).

Because people confuse 4 weeks and 1 month. My friend was counting her baby's months as 4 weeks and I didn't say anything about the "monthly" photoshoots, but when she said that he was nearly 6 months and it must be "time for weaning" I pointed that actually he was only 23 weeks and 3 weeks off. She was very sure that 4 weeks was counted as 1 month when measuring baby ages until I told her that by that metric, 1 year was 13 months.

that is actually quite a good explanation!

Sympathies to anyone who goes the full 2 weeks over, past or future.

Induced at 14 days, with baby arriving a full 17 days after the due date. And even then, she had to be taken out by c-section as she clearly had no intention of going anywhere!

I think you might be me

How can someone not realise that 🤣

I thought the 10 mth thing is because we're pregnant for 9.5 mths, but they always date you from the first day of your last period which makes it 10 mths (even though you're not actually pregnant for the first two weeks!)