Ethan of Athos is a science fiction novel by Lois McMaster Bujold

Warning: Wikipedia contains spoilers

It tells the story of Dr. Ethan Urquhart, Chief of Biology at the Severin District Reproduction Centre on the planet of Athos, and his quest to Kline Station to find out what has happened to a shipment of vital ovarian tissue cultures.

Athos has strict controls on its population, requiring it to be exclusively male. There is strict censorship and a prohibition on anything to do with women. Children are grown in and birthed from uterine replicator machines (an artificial womb) but the ovarian tissue cultures, which are the only source of human eggs, are dying from old age, after 200 years service. The new shipment of ovarian tissue cultures, which the planet has paid hard currency for, have been replaced with dead and animal tissues. The Population Council make Ethan the planet's ambassador and direct him to track down a new supply of tissue cultures and also to find the supplier who handled the shipment, to see if the money can be recovered.

Ethan's first encounter with a woman is when he asks directions from Commander Elli Quinn, an intelligence officer with the Dendarii Free Mercenary Fleet, who is on home leave for the first time in ten years. Ethan discovers he is not the only person looking for the missing Athos tissue cultures. In the process of tracking the shipment down, he gets mixed up in a kidnapping plot by bounty hunters after a fugitive who knows about a mysterious genetic experiment that is connected with the missing cultures.

After some unexpected, and chance, events, Ethan and Elli recover the tissue cultures and have them shipped back to Athos. Though not before Ethan asks if Elli is prepared to make a donation of some of her tissue as well...

See also: Sex in science fiction