The Marriage Guide
Frederick Hollick, M.D.'s The Marriage Guide sounds like it might be a self-help book for newlyweds who cannot figure out how to compromise, but in 1860 the only way to write a book about the science behind sex was to put it in its socially proper place: marriage. Thus, The Marriage Guide or Natural History of Generation is written.
Meant to be instructive nominally "For Married Persons and those about to marry, both male and female," the guide is full of instructive scientific knowledge regarding how how conception occurs and what happens during pregnancy. Thus is includes many images of the female body, but in a turn towards newer trends that occured in the later Victorian era, these images are more of isolated body parts and thus somewhat less sexualized.
Interestingly, it covers both "the production or prevention of off-spring," perhaps a break from social norms of the time, though the engraved frontispiece reads "The triumph of love is a happy and fruitful marriage," (emphasis mine).