What's with the fascination with fruits?

If you've ever been pregnant, you know what I am talking about. Just about every book on pregnancy describes the youngun's size at each stage of development by comparing it to a fruit.

By six weeks, baby will be approximately the size of a grape. By twelve weeks, you've got a lime in the coconut, if you know what I mean. By twenty weeks, you know baby's doing well if you can feel the little avocado bouncing around. It's all well and good, until you get into the third trimester. Then you're in canteloupe stage.

Trust me, it's not fun to be in canteloupe stage.

But why stop the comparisons at birth? By one month, you have a pumpkin. By two months, a watermelon. By 16 months...

um...

Oh, that's why they stop. I get it.

But really, are pregnant women so spaced out with baby bliss that they are incapable of understanding Very Abstract Data such as "one inch long"? Oooh, baby is smaller than the period at the end of this sentence - ah-ha, what if I used an exclamation point! or a question mark?