# Fetal growth rates - How many cells?

**URL:** <https://boards.straightdope.com/t/fetal-growth-rates-how-many-cells/123409>\
**Category:** Factual Questions\
**Created:** [August 11, 2002, 4:30pm UTC](https://boards.straightdope.com/t/fetal-growth-rates-how-many-cells/123409 "2002-08-11T16:30:04Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Neptune](https://avatars.discourse-cdn.com/v4/letter/n/b5a626/32.png) [@Neptune](https://boards.straightdope.com/u/Neptune)\
**Post date:** [August 11, 2002, 4:30pm UTC](https://boards.straightdope.com/t/fetal-growth-rates-how-many-cells/123409/1 "2002-08-11T16:30:04Z")

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I tried to search the web for a table like this and couldn’t find anything.

How many cells does a human fetus have at different stages? How many cells at one hour from conception, at one day, at one week, at one month, two months, three months, and so on. How many cells in a newborn? How many cells in my adult body?

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**Author:** ![DMC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dmc/32/18049_2.png) [@DMC](https://boards.straightdope.com/u/DMC)\
**Post date:** [August 11, 2002, 5:04pm UTC](https://boards.straightdope.com/t/fetal-growth-rates-how-many-cells/123409/2 "2002-08-11T17:04:19Z")

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I doubt such a table exists, due to the wide variance in cell count estimates and the variance between one person and another. Even a single individual’s cell count changes from day to day.

If you want the counts for the first week or so, those are pretty reliable, but after that it’s educated guesswork. To give you an idea of why, the adult body is estimated to consist of between 10 trillion and 100 trillion cells. Not only is that a large number, but there is a 90 trillion cell difference between the two. Not very exacting.

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**Author:** ![Neptune](https://avatars.discourse-cdn.com/v4/letter/n/b5a626/32.png) [@Neptune](https://boards.straightdope.com/u/Neptune)\
**Post date:** [August 11, 2002, 9:19pm UTC](https://boards.straightdope.com/t/fetal-growth-rates-how-many-cells/123409/3 "2002-08-11T21:19:38Z")

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According to the last time I stepped on the scale, I must be one of those hundred trillioners.

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**Author:** ![Washte](https://avatars.discourse-cdn.com/v4/letter/w/dc4da7/32.png) [@Washte](https://boards.straightdope.com/u/Washte)\
**Post date:** [August 12, 2002, 10:04am UTC](https://boards.straightdope.com/t/fetal-growth-rates-how-many-cells/123409/4 "2002-08-12T10:04:14Z")

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This site offers a good [description](http://www.sanfordcpc.org/Fetal%20Development.htm) .

One site I found says that division was

> [@](#):
>
> 16 to 32 cells by 3 days…it has formed into a ball called a morula

This site provides a [timeline](http://members.tripod.com/~peacepigeon/fetal.html) , but there is only a couple mentions of cellular divisions - apart from the obvious first split that begins the miracle…

> [@](#):
>
> at 7-10 days after conception he will have grown from a single cell into 128 to 256 cells.

I’m sure with enough Googling you could find the cell divisions you are looking for.

I agree with **Neptune** 😃