The cycle pregnancy rate is normal in baboons with stage I endometriosis but decreased in primates with stage II and stage III - IV disease. - D'Hooghe,T.M.; Bambra,C.S.; Raeymaekers,B.M.; Riday,A.M.; Suleman,M.A.; Koninckx,P.R. (Fertil Steril, 1996)