年紀對於精蟲之影響

研究顯示，年紀對於精蟲之影響如下
>34歲，精蟲數量逐漸下降
>40歲，精蟲形狀正常比率逐漸下降
>43歲，精蟲活動力逐漸下降
>45歲，精液量逐漸下降

http://www.ncbi.nlm.nih.gov/pubmed/23809502

Fertil Steril. 2013 Jun 27. pii: S0015-0282(13)00687-0. doi: 10.1016/j.fertnstert.2013.05.046. [Epub ahead of print]

Age thresholds for changes in semen parameters in men.

Stone BA, Alex A, Werlin LB, Marrs RP.

Source

Reproductive Technology Laboratories, Los Angeles, California; Utah Fertility Partners, Pleasant Grove, Utah. Electronic address: bstone@californiafertilitypartners.com.

Abstract

OBJECTIVE:

To determine whether age thresholds for elements of semen quality exist.

DESIGN:

Retrospective analysis (covariance and point-change analysis) of results of 4,822 semen analyses and 259 fluorescence in situ hybridization (FISH) analyses.

SETTING:

Reference laboratory within an infertility clinic.

PATIENT(S):

A total of 5,081 men aged 16.5-72.3 years.

INTERVENTION(S):

None.

MAIN OUTCOME MEASURE(S):

Ejaculate volume, sperm concentration, sperm motility, sperm motion parameters, strict morphology, and results of FISH analysis.

RESULT(S):

Measured parameters of ejaculates did not change before 34 years of age. Immediately thereafter, total sperm numbers (and total motile) declined. Sperm concentration and the proportion of sperm of normal morphology declined after 40 years. Sperm motility and progressive parameters of motile sperm fell after 43 years and ejaculate volume after 45 years. The ratio of Y:X-bearing sperm in ejaculates decreased only after 55 years.

CONCLUSION(S):

Our findings project a declining likelihood of pregnancy following intercourse with men >34 years old, independent from the woman's age and increasing with advancing age. Age-related mechanisms associated with this oligoasthenoteratozoospermic progression are discussed.