We are still working on this, but the most relevant tidbit I've found in the meantime is the following:
"Journalists Release Guantanamo Bay Report" by Ashfaq Yusufzai (Inter Press Service (IPS), July 31, 2006)
[excerpt]
"Startlingly, [two Afghan journalists released from the prison at Guantanamo Bay] also claimed to have seen evidence of female inmates in Guantanamo. 'We saw forms filled in by female inmates at the office of the investigators.'
"One of the forms, left lying around carelessly on a table by U.S. military investigators, had apparently been filled in by a woman from Lahore, in the Punjab province of Pakistan, and it showed that she was pregnant, they said."
It was also pointed out by another Rad Ref librarian that this is not the sort of solid, confirmable information likely to be found published anywhere. Pulitzer Prize-winning journalists have come up with less. Even the International Committee of the Red Cross reports on Guantanamo detainees are confidential and not released to the general public:
