The Nearness of You by Amanda Eyre Ward

Successful, driven heart surgeon Suzette is caught off guard when her husband, Hyland, tells her that he'd like them to have a child. Married now for fifteen years, they had agreed that they weren't going to have children, because Suzette feared passing on her mother's mental illness. Hyland explains that he would like them to have a baby with a surrogate. Reluctant at first, Suzette agrees. After several false starts, a young woman named Dorrie agrees to be their surrogate, hoping that she can use the money she receives to go to college, but things don't go as planned... Taking place over the next fifteen years, the book explores the bonds of motherhood, marriage, and what it means to be a family.