Ethan of Athos — Lois McMaster Bujold

You might think that an obstetrician on a planet forbidden to women would be underemployed .. .

Not so; Dr. Ethan Urquhart, Chief of Biology at the Severin District Reproduction Center, is one of the busiest men on the planet Athos. That is, until a mysterious genetic crisis threatens Athos with extinction.

Drafted to brave the wider universe in quest of new ovarian tissue cultures, Ethan braces himself for his first encounter with alien beings . . . women. But not in his wildest imaginings is he prepared for an alliance with Commander Elli Quinn, an utterly gorgeous free mercenary intelligence officer, who has her own secret interests in Athos's problems.