The novel was met with critical success and praise for crafting a tender exploration of gender, parenthood, love, and trans life.

Because of his complicated relationship with his gender, Ames is hesitant to accept the role of a father to a child in a heterotypical family because of the label's social connotations of masculinity.

Ames reconnects with Reese, who has long wanted to mother a child of her own, believing that the three of them could form an unconventional family to raise the baby together.

Reese grapples with the same self-destructive coping mechanisms that soured her old relationship with Amy, including sex with married men and chasers, while Ames tries to navigate life as a man again.

Katrina attempts to adjust to a different understanding of gender and questions her own queerness, but intends to get an abortion if she cannot be sure she will have a support system.

[11][12][13][14] Kirkus called Detransition, Baby "a wonderfully original exploration of desire and the evolving shape of family.

[15] Writing for The New Yorker, Crispin Long identifies the novel as "a bourgeois comedy of manners" and notes that Peters is "refreshingly uninterested in persuading the public of the bravery and nobility of trans people, and lets them be as dysfunctional as anyone else.

"[16] In a review for Vox, Emily St. James praised the depiction of Ames as someone "just trying to fumble his way through a life that has afforded him very few good options.

[20] Authors including Melinda Salisbury, Joanne Harris, and Naoise Dolan—another nominee for the 2021 prize—condemned the letter and expressed their support for Peters.

The organisers of the prize released a statement condemning the letter and defending the decision to nominate Peters' book.