- Fertile women (defined as those who are not surgically sterile, are not >1 year post-menopausal or who are not currently using or complying with a medically approved method of contraception). Lubiprostone has not been studied in pregnant women and should only be used during a pregnancy if the potential benefits justify the potential risk to the fetus. Women should have a negative pregnancy test before beginning treatment with lubiprostone and need to practice effective contraceptive measures