0.001) y la población general (p>0.001). Conclusiones: Basado en este análisis, la concentración normal estaría alrededor de 65 millones por mL. Usando valor de referencia, solo el 25% de los estudios con hombres infértiles estaría por encima del rango, y el 75% de los estudios con hombres fértiles estarían en este grupo (>65 x 106 espermatozoides/mL).]]>
0.001) and in the general population (p>0.001). Conclusion: Based on this analysis the normal sperm count is about 65 million per mL. Using these reference value, only the 25% of the studies in infertile men are above this value, and the 75% studies with fertile men (>65 x 106 sperm/mL).]]>
Concentración espermática. ¿Necesitamos un nuevo valor de referencia?
Sperm count. Do we need a new reference value?
Walter Cardona Maya
Grupo Reproducción. Universidad de Antioquia. Medellín. Colombia.
Dirección para correspondencia
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RESUMEN
Objetivos: Evaluar las concentraciones espermáticas de individuos fértiles, población general e individuos infértiles en diferentes regiones del mundo.
Métodos: Las concentraciones espermáticas de diferentes estudios según el estado fértil de cada individuo fue evaluada: individuos con fertilidad comprobada, individuos que consultan a una clínica de andrología o centro de infertilidad y población general.
Resultado: El promedio de la concentración espermática observada en los estudios para cada grupo fue diferente, siendo menos en los hombres infértiles comparado con los hombres fértiles (p>0.001) y la población general (p>0.001).
Conclusiones: Basado en este análisis, la concentración normal estaría alrededor de 65 millones por mL. Usando valor de referencia, solo el 25% de los estudios con hombres infértiles estaría por encima del rango, y el 75% de los estudios con hombres fértiles estarían en este grupo (>65 x 106 espermatozoides/mL).
Palabras clave: Espermatozoide. Concentración espermática. Valores de referencia. Calidad seminal.
SUMMARY
Objectives: To evaluate the sperm count in fertile men, general population, and infertile men in different regions of the world.
Methods: Sperm counts were recorded according to their fertility status, proven fertility, men recruited from an andrology/infertility clinic, or healthy men ]]>
Results: The average of sperm count in the different studies is lower in infertile men that in fertile men (p>0.001) and in the general population (p>0.001).
Conclusion: Based on this analysis the normal sperm count is about 65 million per mL. Using these reference value, only the 25% of the studies in infertile men are above this value, and the 75% studies with fertile men (>65 x 106 sperm/mL).
Key words: Spermatozoa. Sperm count. Reference value. Semen quality.
Introducción
Es universalmente aceptado que el análisis seminal es una prueba fiable que da información sobre el potencial fértil de un individuo, y el conteo espermático es uno de los más importantes y cuantitativo parámetro que se obtiene durante en el análisis espermático. Aunque la Organización Mundial de la Salud (OMS, 1), ha reportado valores normales para el análisis seminal, existen sesgos en estos valores de referencia.
Acorde con Sandler y cols, (2) el valor de referencia original establecido en 1934 para considerar a un hombre incapaz embarazar a una mujer era de menos de 60 millones/mL. Dos décadas después este valor cambio, y se considero que 50 millones/mL era el límite inferior para considerar a un individuo fértil. En 1950, un nuevo valor de referencia fue establecido basado en un estudio de 1000 individuos, y fue reportado que 20 millones/mL era el limite inferior debido a que mas del 95% de los hombres fértiles usados en dicho estudio presentaban valores superiores (3). Adicionalmente, varios autores en diferentes regiones del mundo han intentado determinar el correcto valor para diferenciar entre individuos fértiles e infértiles; por ejemplo, Guzick y cols, (4) observan que los individuos fértiles tienen una concentración espermática mayor a 48 millones/mL, mientras los individuos subfebriles presentan valores menores a 13.5 millones/mL. Por lo tanto el objetivo de este estudio fue evaluar las concentraciones espermáticas de individuos fértiles, población general e individuos infértiles en diferentes regiones del mundo.
Materiales y métodos
En el presente estudio se realizó un análisis de 102 estudios previamente publicados (2-103) en los cuales se reportaba la concentración espermática en población general, hombres fértiles e infértiles incluyendo el estudio de Carlsen y cols, (5), en el cual se muestra como la concentración espermática declino significativamente desde 1938 a 1990.
]]> Los datos provenientes de cada estudio fueron documentados acorde con su estado de fertilidad: fertilidad probada (hombres fértiles); hombres reclutados en clínicas de andrología o de infertilidad (hombres infértiles); y hombres sanos (población general); adicionalmente. La concentración espermática fue evaluada en 59 artículos (hombres totales = 14919), en 21 artículos de hombres infértiles (hombres totales = 25963), y en 37 artículos de la población general (hombres totales = 12769).La media de los promedios de la concentración espermática en los diferentes grupos estudiados mostro un menor promedio en el grupo de individuos infértiles (50.9±25.7) comparado con el valor obtenido en el grupo de individuos fértiles (83±23.7, p>0.001) y en la población general (82.1±23.2, p>0.001), Figura 1. Adicionalmente, usando el análisis de percentiles se observa que el percentil 25 en el grupo de individuos fértiles y en la población general es similar al percentil 75 en los hombres infértiles, 62.4, 66 and 68.2, respectivamente.
Discusión
Yo propongo que un nuevo valor de referencia para la concentración espermática podría ser determinado basado en este análisis, el cual estaría alrededor de 65 millones por mL. Usando estos resultados yo estoy seguro que solo el 25% de los estudios de hombres infértiles no estarían en el grupo de hombres infértiles, y que el 75% de los estudios realizados con hombres fértiles estarían en el grupo de hombres fértiles.
Conclusiones
Por lo tanto, en el fututo este valor de referencia podría ser mas exacto que el valor de referencia actual considerado como normal, es decir más de 20 millones/mL.
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Dirección para correspondencia:
Walter Cardona Maya
Grupo Reproducción ]]>
Universidad de Antioquia
Medellín. A.A.1226 (Colombia)
wdcmaya@medicina.udea.edu.co
Aceptado para publicar: 24 de abril 2009.
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