To anyone of a cynical disposition, the joyful phrase “We’re pregnant” comes across not as charming but twee — or even, when uttered by the male, insufferably presumptuous. The narrator of Peter Ho Davies’s new novel is all too conscious of the asymmetry of childbearing. Is he an active participant in this nine-month drama, or is he merely, after the fun part, not much more than a worried bystander?

Though the American family at the heart of the narrative have enough quirks to be distinctive, the absence of names renders them emblematic. They are “the father”, “the mother” and “the baby”, later “the boy”. The central image is the flipped coin of randomness. “There was a chance the baby was normal. There was a chance the baby was not.” While tests are run on the foetus, the father — like Davies, a creative writing professor with a science background — meditates on that perplexing quantum feline, Schrodinger’s Cat, somehow both alive and dead. It’s significant, he feels, that “pussy” is a slang term for female genitalia.

“He” is an overthinker, pondering paradoxes, metaphors and word meanings; “she” is more pragmatic, even blunt. The desire for a child seems the only thing keeping them together. He wants more sex than she does (“He isn’t sure if he is pushing something into her, or driving something out”), but she wants a baby more than he does. Initial hope turns to disappointment, and quickly, on his part, to a deepening sense of shame. Eventual success only gives rise to more anxieties, more questions. ‘“What have we done?” his wife whispers as they take the baby home.

There are near-universal parental experiences — pets, potties, “the state of filth where Cheerios get everywhere” — and some unique to the parents of children whose development unaccountably lags. Paediatricians, specialists, physical therapists, specific activities, tools and toys, the A-word: all of this counts as material, and the father slowly begins to work with it, with the mother’s permission. One of the things he discusses in his classes is appropriation: “Young writers get exercised about these things, what they are and aren’t allowed to write.” He reflects that it’s because they want to be good people, “except he’s not sure writers are good people.”

An instruction the narrator gives his students — “avoid the autobiographical assumption” — is something Davies himself plays with knowingly in this text. The narrator talks about “the cover” fiction provides: “A story can be 1% true and 99% made up, or 99% true and 1% made up, and the reader won’t know the difference.” Clearly there is some professional overlap between author and narrator; they both write “slim volumes” at wide-spaced intervals, though Davies’s prize-bedecked career, unlike his character’s, can’t be described as “in the doldrums”. As to the personal trauma, it’s anybody’s guess, and nobody’s business.

In a relatively brief narrative, Davies encompasses some of the hugest questions of life, sex, morality and mortality. The prose might be spare and elegant, but the mess, muddle and sheer silliness of ordinary life is sharply evoked. A book about fatherhood becomes a book about writing a book about fatherhood; because the lie someone told you is fiction itself.

A Lie Someone Told You About Yourself by Peter Ho Davies, Sceptre £14.99,  192 pages