Jane Villanueva, the titular character in Jane the Virgin, becomes pregnant due to an accidental artificial insemination.
More specifically, Jane, a 23-year-old virgin, goes to her gynecologist, Dr. Luisa Alver, for a routine check-up. Unbeknownst to Jane, Dr. Alver is going through a difficult personal time and is distracted. At the same time, Luisa's brother, Rafael Solano, has stored his sperm at the clinic as he is recovering from cancer treatment and wants to preserve his fertility. Due to a mix-up and Luisa's negligence, Jane is accidentally artificially inseminated with Rafael's sperm. This sets the stage for the entire plot of the show, which explores the complexities and comedic situations that arise from this unexpected pregnancy.