- Email: [email protected]
Use of Pentoxifylline in IVF—Helpful?
Dana A. Ohl, M.D. Department of Surgery, Section of Urology University of Michigan Ann Arbor, MI April 14, 1993 REFERENCES 1. Keel BA, Webster BW. Semen analysis data from fresh and
cryopreserved donor ejaculates: comparison of cryoprotectants and pregnancy rates. Fertil Steril 1989;52:100-5. 2. Hurd WW, Menge AC, Randolph JF, Ohl DA, Ansbacher R, Brown AN. Comparison of intracervical, intrauterine, and intratubal techniques for donor insemination. Fertil Steril 1993;59:339-42. 3. Byrd W, Bradshaw K, Carr B, Edman C, Odan J, Ackerman G. A prospective randomized study of pregnancy rates following intrauterine and intracervical insemination using frozen donor sperm. Fertil SteriI1990;53:521-7.
Use of Pentoxifylline in IVF-Helpful?
in vitro insemination may have been too long for the pentoxifylline effect to be maintained (2). In a somewhat oversimplified manner, pentoxifylline appears to be useful in IVF in two particular conditions: insufficient number of rapidly moving and hyperactivated spermatozoa after incubation for in vitro capacitation, and the insufficiency of the (stimulus-induced) acrosome reaction (AR). The former condition, and the degree of improvement with pentoxifylline, can be identified by computer-assisted sperm movement analysis of incubated sperm samples before and after pentoxifylline addition. Cases falling into the latter category can be selected by examining the effects of pentoxifylline on the spontaneous and stimulus-induced AR (3); pentoxifylline is indicated when it sensitizes spermatozoa to AR stimuli without exerting considerable direct effects on the AR frequency. At our Center, pentoxifylline is used in these two indications for more than 1 year with very encouraging results.
To the Editor (Letter 1 of 2): In a recent article (1), Tournaye et al. report the lack of a beneficial effect of pentoxifylline (Trental; Sigma, St. Louis, MO) on IVF results in 22 couples with previous IVF failure. Even though the authors wisely admit at the end of their paper that pentoxifylline might be more effective when applied to a selected subgroup of patients, the title of the article is potentially misleading. The number of cases included in the study appears too small to warrant a negative statement about the therapeutical usefulness of a drug. Moreover, recently published data (2,3) can help to improve the conditions of pentoxifylline application and to determine the cases in which its use should be indicated. Because these data were published after the acceptance of the above article (1), this is not a criticism, merely a comment destined to those considering the use of pentoxifylline in their IVF program. As to the series reported by Tournaye et al. (1), the possible explanations of their negative findings are the following: first, pentoxifylline was applied indiscriminately in a heterogeneous group of patients, which possibly involved those with defects of sperm-zona pellucida recognition where pentoxifylline is probably of no help; second, the pentoxifylline treatment was combined with the swim-up technique, which is less efficient than Percoll (Pharmacia, Uppsala, Sweden); and third, the approximately 2.5-hour interval between the removal of pentoxifylline from sperm incubation media and Vol. 60, No.2, August 1993
Jan Tesarik, M.D., Ph.D. Center for Reproductive Biology and Medicine American Hospital of Paris Neuilly sur Seine, France February 8, 1993 REFERENCES 1. Tournaye H, Janssens R, Camus M, Staessen C, Devroey P,
Van Steirteghem A. Pentoxifylline is not useful in enhancing sperm function in cases with previous in vitro fertilization failure. Fertil Steril 1993;59:210-5. 2. Tesarik J, Thebault A, Testart J. Effect ofpentoxifylline on sperm movement characteristics in normozoospermic and asthenozoospermic specimens. Hum Reprod 1992;7:125763. 3. Tesarik J, Mendoza C, Carreras A. Effects of phosphodiesterase inhibitors caffeine and pentoxifylline on spontaneous and stimulus-induced acrosome reactions in human sperm. Fertil Steril 1992;58:1185-90.
To the Editor (Letter 2 of 2): Tournaye et al. (1) concluded in their recent article that pentoxifylline is not useful in enhancing sperm function in cases with previous IVF failure. We wish to make the following comments: Compacting the semen at 750X g for the pellet/ swim-up technique can exacerbate cellular damage caused by oxygen free radicals (2) and give an inadequate and unequal exposure to pentoxifylline, which is not the case when sperm suspensions are Letters-to-the-editor
377
cryopreserved donor ejaculates: comparison of cryoprotectants and pregnancy rates. Fertil Steril 1989;52:100-5. 2. Hurd WW, Menge AC, Randolph JF, Ohl DA, Ansbacher R, Brown AN. Comparison of intracervical, intrauterine, and intratubal techniques for donor insemination. Fertil Steril 1993;59:339-42. 3. Byrd W, Bradshaw K, Carr B, Edman C, Odan J, Ackerman G. A prospective randomized study of pregnancy rates following intrauterine and intracervical insemination using frozen donor sperm. Fertil SteriI1990;53:521-7.
Use of Pentoxifylline in IVF-Helpful?
in vitro insemination may have been too long for the pentoxifylline effect to be maintained (2). In a somewhat oversimplified manner, pentoxifylline appears to be useful in IVF in two particular conditions: insufficient number of rapidly moving and hyperactivated spermatozoa after incubation for in vitro capacitation, and the insufficiency of the (stimulus-induced) acrosome reaction (AR). The former condition, and the degree of improvement with pentoxifylline, can be identified by computer-assisted sperm movement analysis of incubated sperm samples before and after pentoxifylline addition. Cases falling into the latter category can be selected by examining the effects of pentoxifylline on the spontaneous and stimulus-induced AR (3); pentoxifylline is indicated when it sensitizes spermatozoa to AR stimuli without exerting considerable direct effects on the AR frequency. At our Center, pentoxifylline is used in these two indications for more than 1 year with very encouraging results.
To the Editor (Letter 1 of 2): In a recent article (1), Tournaye et al. report the lack of a beneficial effect of pentoxifylline (Trental; Sigma, St. Louis, MO) on IVF results in 22 couples with previous IVF failure. Even though the authors wisely admit at the end of their paper that pentoxifylline might be more effective when applied to a selected subgroup of patients, the title of the article is potentially misleading. The number of cases included in the study appears too small to warrant a negative statement about the therapeutical usefulness of a drug. Moreover, recently published data (2,3) can help to improve the conditions of pentoxifylline application and to determine the cases in which its use should be indicated. Because these data were published after the acceptance of the above article (1), this is not a criticism, merely a comment destined to those considering the use of pentoxifylline in their IVF program. As to the series reported by Tournaye et al. (1), the possible explanations of their negative findings are the following: first, pentoxifylline was applied indiscriminately in a heterogeneous group of patients, which possibly involved those with defects of sperm-zona pellucida recognition where pentoxifylline is probably of no help; second, the pentoxifylline treatment was combined with the swim-up technique, which is less efficient than Percoll (Pharmacia, Uppsala, Sweden); and third, the approximately 2.5-hour interval between the removal of pentoxifylline from sperm incubation media and Vol. 60, No.2, August 1993
Jan Tesarik, M.D., Ph.D. Center for Reproductive Biology and Medicine American Hospital of Paris Neuilly sur Seine, France February 8, 1993 REFERENCES 1. Tournaye H, Janssens R, Camus M, Staessen C, Devroey P,
Van Steirteghem A. Pentoxifylline is not useful in enhancing sperm function in cases with previous in vitro fertilization failure. Fertil Steril 1993;59:210-5. 2. Tesarik J, Thebault A, Testart J. Effect ofpentoxifylline on sperm movement characteristics in normozoospermic and asthenozoospermic specimens. Hum Reprod 1992;7:125763. 3. Tesarik J, Mendoza C, Carreras A. Effects of phosphodiesterase inhibitors caffeine and pentoxifylline on spontaneous and stimulus-induced acrosome reactions in human sperm. Fertil Steril 1992;58:1185-90.
To the Editor (Letter 2 of 2): Tournaye et al. (1) concluded in their recent article that pentoxifylline is not useful in enhancing sperm function in cases with previous IVF failure. We wish to make the following comments: Compacting the semen at 750X g for the pellet/ swim-up technique can exacerbate cellular damage caused by oxygen free radicals (2) and give an inadequate and unequal exposure to pentoxifylline, which is not the case when sperm suspensions are Letters-to-the-editor
377