Anna Alcott is an actress trying to get pregnant, and Danielle Valentine spends a considerable amount of the book on what that actually involves: the injections, the appointments, the scheduling of a body around a medical process, and the particular way a public career interacts with all of it.
Then things start going wrong in ways Anna cannot get anyone to take seriously. Appointments she did not make. A man she keeps seeing. Symptoms that do not fit. She becomes certain that someone is tampering with her pregnancy on purpose.
Everyone around her has an available explanation that does not require believing her: hormones, stress, the drugs, her history. Her husband, her friends and her doctors all reach for it. The novel is horror built out of an ordinary and very well-documented fact, which is how readily a pregnant woman's account of her own body gets set aside, and it does not resolve the ambiguity early.