This poem definitely has a form, but it's not one that you've heard of before because it's particular to this poem—you could say it's custom fit, perhaps maternity fit.
The first line gives us a big hint about the form—each line has nine syllables. Count on down, and you'll find that the poem is nine lines long. This makes us think of the term of pregnancy—nine months. Writing nine lines, nine syllables each, is a pretty clever way to structure a poem about pregnancy.
As for a specific meter, or formalized rhythm, the lines are pretty all over the board in terms of which syllables they emphasize. Still, the poem has a lovely flow, by relying on sonic tricks like alliteration and assonance. And just like with meter, the poem has no highly structured rhyme scheme. Yet words like "syllables," "tendrils" and "apples" provide some end rhyme as well as the slant rhyme of "purse" and "house." Be sure to check out our "Sound Check" section for more.