In this poem, the narrator is describing her pregnancy in metaphorical language, exploring an ambivalence about it.
She first announces herself as a "riddle in nine syllables" (the poem is also nine lines long). She then describes herself as an elephant, similar to a huge house. She is also like a watermelon, walking along on two small legs, though she praises both the “red fruit” of her belly and the “fine timbers” of her legs. She then compares herself to a loaf of bread, its yeast rising big and full, and a coin purse stuffed with newly-minted money.
She views herself as simply a “means," a carrier for a child. She is merely a “stage,” a hardworking “cow in calf.” She believes she looks as though she has eaten a large bag of green apples. Ultimately, since there is nothing she can do about her pregnancy, she sees herself as having boarded a train which she cannot leave.
"Metaphors" is a very short poem from 1959. Plath announces that she is a riddle in nine syllables, and then uses a multitude of seemingly unrelated metaphors to describe herself. However, it is clear upon inspection that she is describing a state of pregnancy. The nine lines correspond to the nine months of pregnancy, and each line possesses nine syllables. Plath was pregnant with her first child, Frieda, at the time of the poem's composition. Though most critics concur that Plath's healthiest relationships in life were with her two children, the poem suggests a deep ambivalence about motherhood. The basic conflict is the poem is that of duty vs. individuality. The narrator feels that by subsuming herself to the duty of motherhood, her own individuality is being stifled. Though the poem uses consistent first person, the ironic effect is that the speaker's individuality is only expressed in terms of the child she carries. She is aware of herself, but only in terms of what she cannot be.
While some of the poem's images are rather humorous - she describes a pregnant woman as "a melon strolling on two tendrils," for instance - the overall depiction of pregnancy is not very heartening. The woman, whom readers should assume is Plath herself, is discouraged by her physical appearance. She feels large and unwieldy, comparing herself to an elephant, a "cow in calf," and a "ponderous house." She expresses no joy with her increasing size. Instead, she is too well-aware of how she has lost control of her body. She lacks individuality, and is instead only a "means" and a "stage" for another. Everything happening to her is for someone else, not for herself.
The bleakness of this situation is crystallized in the last line of the poem – "Boarded the train there's no getting off." Here, she suggests that she lacks any agency, and is instead at the mercy of another. She implies that her feelings about the child mean nothing; she must carry the pregnancy to term. She has no choice in the matter. Quite obviously, the stereotypical image of the glowing, exuberant pregnant woman is not found in "Metaphors." The famed Plath scholar Stephen Gould Axelrod agrees, writing that "Beneath the humor of Plath’s imagery, we discover very little real pleasure...indeed, in the last two lines even the humor vanishes, displaced by anxious awareness of remorseless fate."
Upon closer analysis, Plath's choice of imagery reinforces her belief that she is simply a carrier. For instance, an elephant is valuable not for itself, but for its ivory. The timber of a house is valuable only for what it contains - a family - and not in itself. A purse is insignificant; only the money which it holds matters. Her evocation of green apples suggests both a sour, uncomfortable treat, but also offers an implicit allusion to Eve, who ate an apple from the tree of knowledge and thus cursed all women with the legacy of painful childbirth.
It is not surprising that Plath was so ambivalent about motherhood. As a young woman who had high hopes for her academic and literary career, motherhood could, and did, place limitations on her productivity. She had little time to work on her writing after Frieda and Nicholas were born, while husband Ted Hughes could devote his time towards a professional literary career. Resentment grew for her as she placed her husband, children, and housewifely duties before her career. Women in the 1950s and 1960s often experienced this problem, clearly documented in Betty Freidan's 1963 book The Feminine Mystique. Plath's struggle to harness her creative powers amid the overwhelming solitude and monotony of motherhood manifested itself in "Metaphors" even before she gave birth, and she would continue to explore this theme throughout the rest of her life and work.