Cómo y cuándo el levonorgestrel previene el embarazo si se administra como anticonceptivo de emergencia

Horacio Croxatto Avoni, María Elena Ortiz Scarlazetta

Resumen


En esta revisión se actualiza el mecanismo de acción del levonorgestrel (LNG) usado en anticoncepción de emergencia. El análisis crítico de la estimación de la eficacia anticonceptiva del LNG indica que su tasa de falla es más alta que la publicada. El LNG aumenta la viscosidad del moco cervical impidiendo que los espermatozoides del reservorio cervical vayan a renovar la población espermática en el sitio de fecundación. Diversos autores han documentado que LNG suprime el pico preovulatorio de gonadotrofinas e interfiere con el proceso ovulatorio en la mujer y en modelos animales. Administrado después de la ovulación en rata, en la mona Cebus apella y en la mujer, no interfiere con la implantación del embrión. Se concluye que LNG previene el embarazo solamente cuando se administra en un momento del ciclo menstrual en el cual puede impedir la fecundación y que el método falla cuando la administración es más tardía.

Palabras clave


levonorgestrel; migración espermática; ovulación.

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Referencias


McLean J. M., Van Vagenen G. Compounds interfering with ovum implantation and development. III The role of estrogens. Am J Obst Gynecol 1966; 96: 804-15.

Haspels A. A. Interception. Postcoital estrogens in 3,016 women. Contraception 1976; 14: 375-81. 3 Yuzpe A. A., Lancee W. J. Ethinylestradiol and dl-norgestrel as a postcoital contraceptive. Fertil Steril 1977; 28: 932-6.

World Health Organization Task Force on Postovulatory Methods of Fertility Regulation. Randomized controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Lancet 1998; 352: 428-33.

Croxatto H. B., Devoto L., Durand M., Ezcurra E., Larrea F., Nagle C., Ortiz M. E., Vantman D., Vega M., von Hertzen H. Mechanism of action of hormonal preparations used for emergency contraception: a review of the literature. Contraception 2001; 63: 111-21.

Croxatto H. B., Ortiz M. E., Müller A. L. Mechanism of action of emergency contraception. Steroids 2003; 68: 1095-8.

Croxatto H. B., Ortiz M. E. Mecanismo de acción del levonorgestrel en la anticoncepción de emergencia. Rev Chil Obstet Ginecol 2004; 69: 157-62.

Croxatto H. B., Ortiz M. E. Cómo y cuándo el levonorgestrel previene el embarazo cuando se administra como anticonceptivo de emergencia. Población y Salud en Mesoamérica. Revista electrónica publicada por el Centro Centroamericano de Población Universidad de Costa Rica, 2060 San José, Costa Rica http: //ccp.ucr.ac.cr/revista/ 2007; 4: artículo 3.

Croxatto H. B., Ortiz M. E. Anticoncepción de Emergencia con Levonorgestrel. En E. Guzmán (ed). Selección de temas en Ginecoobstetricia. Tomo II. Ediciones Publimpacto, Santiago, 2008. pág. 829-844.

Von Hertzen H., Piaggio G., Ding J., Chen J., Song S., Bartfai G., Ng E., Gemzell-Danielsson K., Oyunbileg A., Wu S., Cheng W., Ludicke F., Pretnar-Davorec A., Kirkman R., Mittal S., Khomassuridze A., Apter D., Peregoudov A. Low dose mifepristone and two regimens of levonorgestrel for emergency contraception: a WHO multicentre randomized trial. Lancet 2002; 360: 1803-10.

Ngai S. W., Fan S., Li S., Cheng L., Ding J., Jing X., Ng E. H. Y., Ho P. C. A randomized trial to compare 24h versus 12h double dose regimen of levonorgestrel for emergency contraception Human Reprod. 2005; 20: 307-11.

Piaggio G., von Hertzen H. Effect of the delay in the administration of levonorgestrel for emergency contraception. XVII FIGO Congress of Gynecology and Obstetrics, 2-7 November 2003, Santiago, Chile.

Espinós J. J., Rodríguez-Espinosa J., Senosiain R., Aura M., Vanrell C., Gispert M., Vega C., Calaf J. The role of matching menstrual data with hormonal measurements in evaluating effectiveness of postcoital contraception. Contraception 1999; 60: 243-7.

Espinós-Gómez J. J., Senosian R., Mata A., Vanrell C., Bassas Ll., Calaf J. What is the seminal exposition among women requiring emergency contraception? A prospective observational comparative study. European Journal of Obstetrics & Gynecology and Reproductive Biology 2006; 131: 57-60.

Raymond E., Taylor D., Trussel J., Steiner M. J. Minimum effectiveness of the levonorgestrel regimen of contraception. Contraception 2004; 69: 79-81.

Wilcox A. J., Weinberg C. R., Baird D. D. Timing of sexual intercourse in relation to ovulation effects on the probability of conception, survival of the pregnancy, and sex of the baby. New Engl. J. Med. 1995; 333: 1517-21.

Espinós-Gómez J. J., Senosian R., Mata A., Vanrell C., Bassas Ll., Calaf J. What is the seminal exposition among women requiring emergency contraception? A prospective observational comparative study. European Journal of Obstetrics & Gynecology and Reproductive Biology 2006; 131: 57-60.

Croxatto H. B., Ortiz M. E., Müller A. L. Mechanism of action of emergency contraception. Steroids 2003; 68: 1095-8.

Gemzell-Danielsson K., Marions L. Mechanism of action of mifepristone and levonorgestrel when used for emergency contraception. Human Reproduction Update, 2004; 10: 341-8.

Wilcox A. J., Weinberg C. R., Baird D. D. Timing of sexual intercourse in relation to ovulation effects on the probability of conception, survival of the pregnancy, and sex of the baby. New Engl. J. Med. 1995; 333: 1517-21.

Wilcox A. J., Weinberg C. R., Baird D. D. Post ovulatory ageing of the oocyte and embryo failure Human reproduction 1998; 13: 394-7.

Wilcox A. J., Weinberg C. R., Baird D. D. Post ovulatory ageing of the oocyte and embryo failure Human reproduction 1998; 13: 394-7.

Croxatto H. B. Female Reproductive Physiology/Function. En K. Heggenhougen, S. Quah (eds) Encyclopedia of Public Health. Vol 2. Academic Press. San Diego 2008 pág. 603-613.

Trussell J., Ellertson C., von Hertzen H., Bigrigg A., Webb A., Evans M., Ferden S., Leadbetter C. Estimating the effectiveness of emergency contraception pills. Contraception 2003; 67: 259-65.

World Health Organization Task Force, óp. cit.

Von Hertzen H. 2002, óp. cit.

Ngai, óp. cit.

Task Force on Postovulatory Methods of Fertility Regulation. Comparison of three single doses of mifepristone as emergency contraception: a randomized trial. Lancet 1999; 353: 607-702.

Hamoda H., Ashok P.W., Stalder C., Flett G. M., Kennedy E., Templeton A. A. randomized trial of mifepristone (10 mg) and levonorgestrel for emergency contraception. Obstet Gynecol 2004; 104: 1307-13.

Espinós, óp. cit.

Stirling A., Glasier A. Estimating the efficacy of emergency contraception-how reliable is the data? Contraception. 2002; 66: 19-22.

Severi F. M., Bocchi C., Florio P., Cobellis L., Ignacchiti E., Petraglia F. Transvaginal ultrasonography in women receiving emergency contraception. Fertil Steril. 2003; 79: 1074-7.

World Health Organization Task Force, óp. cit.

Von Hertzen H. 2002, óp. cit.

Ngai, óp. cit.

Stirling 2002, óp. cit.

Ho P. C., Kwan M. S. A prospective randomized comparison of levonorgestrel with the Yuzpe regimen in post-coital contraception. Hum Reprod 1993; 8: 389-92.

Wilcox 1995, óp. cit.

Dixon G. W., Schlesselman J. J., Howard W. O., Blye R. P. Ethinyl estradiol and conjugated estrogens as postcoital contraceptives. J Am Med Assoc, 1980; 244: 1336-39.

Trussell J., Rodriguez G., Ellerston C. New estimates of the effectiveness of the Yuzpe regimen of emergency contraception. Contraception, 1998; 57: 363-9.

Piaggio 2003, óp. cit.

Piaggio G., von Hertzen H., Grimes D. A., Van Look P. F. On behalf of the Task Force on Postovulatory Methods of Fertility Regulation. Timing of emergency contraception with levonorgestrel or the Yuzpe regimen. Lancet 1999; 353: 721.

World Health Organization, Reproductive Health and Research. Improving access to quality care in family planning: medical elegibility criteria for contraceptive use. 3rd edition. Geneva, 2003. www.who.int/reproductive-health.

World Health Organization 1998, óp. cit.

Von Hertzen 2002, óp. cit.

Piaggio 2003, óp. cit.

Von Hertzen 2002, óp. cit.

Trussell 1998, óp. cit.

Piaggio 2003, óp. cit.

Wilcox 1995, óp. cit.

Yeung W.S., Chiu P.C., Wang C.H., Yao Y.Q., Ho P.C. The effects of levonorgestrel on various sperm functions. Contraception 2002; 66: 453-7.

Bahamondes L., Nascimento J.A.A., Munuce M.J., Fazano F., Faúndes A. The in vitro effect of levonorgestrel on the acrosome reaction of human spermatozoa from fertile men. Contraception 2003; 68: 55-9.

Brache V., Faúndes A., Johansson E., Alvarez F. Anovulation, inadequate luteal phase and poor sperm penetration in cervical mucus during prolonged use of Norplant® implants. Contraception 1985; 31: 261-73.

Croxatto H.B., Diaz S., Salvatierra A.M., Morales P., Ebensperger C., Brandeis A. Treatment with Norplant® subdermal implants inhibits sperm penetration through cervical mucus in vitro. Contraception 1987; 36: 193-201.

Kesserü E., Garmendia F., Westphal N., Parada J. The hormonal and peripheral effects of d-Norgestrel in postcoital contraception. Contraception 1974; 10: 411-24.

Croxatto H. B. Gamete Transport. Cap. 18. En: E. Y. Adashi, J. A. Rock, Z. Rosenwaks (eds): Reproductive Endocrinology, Surgery, and Technology, New York, USA: Lippincot-Raven, 1996; pág. 386-402.

Álvarez F., Brache V., Fernández E., Guerrero B., Guiloff E., Hess R., Salvatierra A. M., Zacharias S. New insights on the mode of action of intrauterine contraception devices in women. Fertil Steril 1988; 49: 768-73.

Kesserü 1974, óp. cit.

Landgren B. M., Johannisson E., Aedo A. R., Kumar A., Yong-en S. The effect of levonorgestrel administered in large doses at different stages of the cycle on ovarian function and endometrial morphology. Contraception 1989; 39: 275-89.

Hapangama D., Glasier A. F., Baird D. T. The effects of peri-ovulatory administration of levonorgestrel on the menstrual cycle. Contraception 2001; 63: 123-9.

Durand M., Cravioto M. C., Raymond E. G., Duran-Sanchez O., De la Luz Cruz-Hinojosa M., Castell-Rodriguez A., Schiavon R., Larrea F. On the mechanism of action of short-term levonorgestrel administration in emergency contraception. Contraception 2001; 64: 227-34.

Marions L., Hultenby K., Lindell I., Sun X., Stabi B., Gemzell Danielsson K. Emergency contraception with mifepristone and levonorgestrel: mechanism of action. Obstet Gynecol 2002; 100: 65-71.

Marions L., Cekan S.Z., Bygdeman M., Gemzell-Danielsson K. Effect of emergency contraception with levonorgestrel or mifepristone on ovarian function. Contraception 2004; 69: 373-7.

Croxatto H. B., Brache V., Pavez M., Cochon L., Forcelledo M. L., Alvarez F., Massai R., Faundes A., Salvatierra A. M. Pituitary-ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75 mg dose given on the days preceding ovulation. Contraception 2004, 70: 442-50.

Hapangama 2001, óp. cit. 66 Durand 2001, óp. cit.. 67 Marions 2002, óp. cit. 68 Marions 2004, óp. cit. 69 Croxatto 2004, óp. cit.

Landgren, óp. cit.

Durand, óp. cit.

Marions 2002, óp. cit.

Ugocsai G., Rozsa M., Ugocsai P. Scanning electron microscopic (SEM) changes of the endometrium in women taking high doses of levonorgestrel as emergency postcoital contraception. Contraception. 2002; 66: 433-7.

Durand M., Seppala M., Cravioto M. C., Koistinen H., Koistinen R., Gonzalez-Macedo J., Larrea F. Late follicular phase administration of levonorgestrel as an emergency contraceptive changes the secretory pattern of glycodelin in serum and endometrium during the luteal phase of the menstrual cycle. Contraception 2005; 71: 451-7.

Vargas M., Tapia A., Henríquez S., Quezada M., Reyes P., Cárdenas H., Noe G., Salvatierra A. M, Gangi L., Monroe D., Velásquez L., Croxatto H. B. Efecto de la administración postovulatoria de levonorgestrel sobre el perfil de expresión de 20.383 genes durante el período de receptividad endometrial analizado por microarreglos de ADN. XIX Reunión Bienal de la Asociación Latinoamericana de Investigadores en Reproducción Humana, ALIRH. Cartagena de Indias, Colombia, mayo 10-13 de 2006.

Wu J., Chen J., Xu R., Zhou P., Wang H., Zhou P. Qiao G., Zhu P., Wang J. Effect of mifepristone and levonorgestrel on the human endometrium during periimplantation. En Ch. P. Puri, P. F. A. Van Look (Eds.): International Conference on Reproductive Health. New Age International (P) Limited, Publishers, New Delhi, 2001, pág. 143-148. 77 Durand 2001, óp. cit. 78 Marions 2002, óp. cit. 79 Durand 2005, óp. cit. 80 Vargas, óp. cit. 81 Landgren 1989, óp. cit.

Ugocsai, óp. cit. 83 Wu 2001, óp. cit. 84 Landgren, 1989, óp. cit. 85 Ugocsai, óp. cit. 86 Wu 2001, óp. cit. 87 Marions 2002, óp. cit. 88 Müller A. L., Llados C., Croxatto H. B. Postcoital treatment with levonorgestrel does not disrupt postfertilization events in the rat. Contraception 2003; 67: 415-9.

Ortiz M. E., Ortiz R. E., Fuentes M. A., Parraguez V. H., Croxatto H. B. Post-coital administration of levonorgestrel does not interfere with post-fertilization events in the New-World monkey Cebus apella. Hum. Reprod. 2004; 19: 1352-56.

Ortiz R. E., Ortiz A. C., Gajardo G., Zepeda A. J., Parraguez V. H., Ortiz M. E., Croxatto H. B. Cytologic, hormonal, and ultrasonographic correlates of the menstrual cycle of the New World Monkey Cebus apella. Am J Primatol 2005; 66: 233-44.

Novikova N., Weisberg E., Stanczyk F. Z., Croxatto H. B., Fraser, I. S. Effectiveness of levonorgestrel emergency contraception given before or after ovulation – a pilot study. Contraception 2007; 75: 112-8.

De Santis M., Cavaliere A. F., Straface G., Carducci B., Caruso A. Failure of the emergency contraceptive levonorgestrel and the risk of adverse effects in pregnancy and on fetal development: an observational cohort study. Fertil Steril 2005; 84: 296-9. 93 Wilcox 1998, óp. cit.

Davidoff F., Trussell J. Plan B and the politics of doubt. JAMA 2006; 296: 1775-8.

Kives S., Hahn P. M., White E., Stanczik F. Z., Reid R. L. Bioavailability of the Yuzpe and levonorgestrel regimens of emergency contraception: vaginal vs. oral administration. Contraception 2005; 71: 197-201.

Vasilaskis C, Jick S. S., Jick H. The risk of venous thromboembolism in users of postcoital contraceptive pills. Contraception 1999; 59: 79-83.

International Planned Parenthood Federation (IPPF). Emergency contraception. In: Medical and Service Delivery Guidelines for Family Planning, 2nd ed. London, IPPF, 1997.

World Health Organization. Emergency Contraception: a guide for service delivery. Geneva, 1998.




DOI: http://dx.doi.org/10.11565/arsmed.v37i2.116



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