What kind of birth defects were found when men take lyrica?

Lyrica is categorized as Pregnancy category C. It was not studied in pregnant women. However, this medication was studied on rats and rabbits. Increased incidences of fetal structural abnormalities, lethality, growth retardation, and nervous and reproductive system functional impairment, were observed in the offspring of rats and rabbits given Lyrica during pregnancy.

Source: PDR drug information for Lyrica.