Ethan of Athos (Vorkosigan Saga)

Dr. Ethan Urquhart, an obstetrician on a planet forbidden to women, is Chief of Biology at the Severin District Reproduction Center and one of the busiest men on the planet Athos. Then a mysterious genetic crisis threatens Athos with extinction. Drafted to brave the wider universe for his cloistered fellows in quest of new ovarian tissue cultures, Ethan braces himself for his first encounter with those most alien of aliens--females of his own species.