"Prayer Before Birth" establishes its unique perspective right away: that of an unborn child ("I am not yet born"). Immediately, then, the poem confronts the reader, asking them to suspend their disbelief and understand that the following "prayer" will be more symbolic than literal.
The speaker fears being born, and feels the need to pray—possibly to God, but maybe also to humanity itself—for future assistance, guidance, and protection. The particular fears contained in this stanza feel like they've been taken from a horror movie, however. Few people, generally speaking, are genuinely afraid of bats, rats, stoats, or "club-footed ghoul[s]"! These are more childlike fears, the stuff of ghost stories. The poem lures the reader into a false sense of security by suggesting that the speaker's fears are unfounded—that speaker's concerns are akin to those of a child scared of monsters in the closet or under the bed.
The sounds of these lines themselves make the fears feel childlike and maybe even a bit comical. Note the strong consonance, assonance, and alliteration at work in these lines, with the intense repetition of /b/, /l/, /t/, /s/, /k/, /uh/, and /ah/ sounds:
[...] the bloodsucking bat or the rat or the stoat or the
club-footed ghoul come near me.
These sounds, combined with the polysyndeton (the repeated "or"), could almost be lifted from a nursery rhyme. In a way, this opening stanza emphasizes the inherent innocence of the speaker, who seems to represents humanity in pure, uncorrupted form.
The first stanza also establishes the overall formula for the poem. Though the poem is written in free verse (without strict meter) and with varying stanza lengths, it nevertheless has a very repetitive structure.
Each stanza (apart from the last) starts with the refrain "I am not yet born" and ends with the word "me" (an example of epistrophe). In this sense, the first stanza sets in motion the prayer-like structure of the poem—think about how Christian prayers often start with an address to God, and end in "Amen." This is part of the poem's overall parallelism, in which grammatical elements of individual sentences or phrases are frequently repeated.