HI, Letrozole may help women with PCOS become pregnant. HERSHEY, Pa. The drug letrozole results in higher birth rates in women with polycystic ovary syndrome (PCOS) than the current preferred infertility treatment drug, according to a nationwide study led by Penn State College of Medicine researchers. Sir you said that letrazol only ovulation drug, but this message passes fertilization occur, am fully confused, pls inform.