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If you search for declining sperm counts you'll find that the evidence is all over the place. It makes a good headline, but studies have it dropping, rising, st

by jemmyw 1y ago

If you search for declining sperm counts you'll find that the evidence is all over the place. It makes a good headline, but studies have it dropping, rising, staying stable. There's no real evidence that people are having a harder time having babies at the same ages they did traditionally. The fertility rate is a social problem, probably (I guess it could be chemically induced behavior)

chneu 1y ago
Except what you're saying isn't true. There is a lot of evidence that fertility, especially male, is dropping. This isnt societal. The actual fertility rate of sperm has been measured to be dropping. This isn't "people aren't having kids." It's "male sperm is less fertile". This is in addition to societal trends in developed countries to have less kids.
- jemmyw 1y ago
  There are a number of studies. I wouldn't call that a lot of evidence, because they don't agree on the results. And, because the methodology changes over time, it's probably just not possible to say that there is evidence of change between pre and post-90s papers. https://www.nature.com/articles/s41585-022-00626-w.epdf https://www.nature.com/articles/s41585-022-00626-w.epdf https://www.scientificamerican.com/article/are-sperm-counts-really-declining/ https://www.scientificamerican.com/article/are-sperm-counts-... There need to be more studies of higher quality to actually establish what is happening. It's really not clear right now that anything is happening, and, if it is, if it's even a problem.
criddell 1y ago
The Cleveland Clinic says sperm counts have been stable for the past 50+ years for men in the US: https://consultqd.clevelandclinic.org/no-cause-for-panic-as-sperm-counts-found-to-be-steady https://consultqd.clevelandclinic.org/no-cause-for-panic-as-...
- bhouston 1y ago
  It is a weird caveat in that study that sort of makes it a tautology: “We found that at least in men with no known fertility challenges, sperm counts are largely stable and haven't changed significantly in the last few years, which is reassuring news." It is a weird exclusion. I response I would ask then if the number of males with fertility issues, and thus excluded, are increasing or also stable. They answer that at the end: "“We didn't track men who were fertile who became infertile. I think based upon the literature so far, that might be the case due to obesity or environmental exposures, and more research is needed to definitively answer that question."

by jemmyw 1y ago

chneu 1y ago

Except what you're saying isn't true. There is a lot of evidence that fertility, especially male, is dropping. This isnt societal. The actual fertility rate of sperm has been measured to be dropping. This isn't "people aren't having kids." It's "male sperm is less fertile". This is in addition to societal trends in developed countries to have less kids.

jemmyw 1y ago
There are a number of studies. I wouldn't call that a lot of evidence, because they don't agree on the results. And, because the methodology changes over time, it's probably just not possible to say that there is evidence of change between pre and post-90s papers. https://www.nature.com/articles/s41585-022-00626-w.epdf https://www.nature.com/articles/s41585-022-00626-w.epdf https://www.scientificamerican.com/article/are-sperm-counts-really-declining/ https://www.scientificamerican.com/article/are-sperm-counts-... There need to be more studies of higher quality to actually establish what is happening. It's really not clear right now that anything is happening, and, if it is, if it's even a problem.

criddell 1y ago

The Cleveland Clinic says sperm counts have been stable for the past 50+ years for men in the US: https://consultqd.clevelandclinic.org/no-cause-for-panic-as-sperm-counts-found-to-be-steady https://consultqd.clevelandclinic.org/no-cause-for-panic-as-...

bhouston 1y ago
It is a weird caveat in that study that sort of makes it a tautology: “We found that at least in men with no known fertility challenges, sperm counts are largely stable and haven't changed significantly in the last few years, which is reassuring news." It is a weird exclusion. I response I would ask then if the number of males with fertility issues, and thus excluded, are increasing or also stable. They answer that at the end: "“We didn't track men who were fertile who became infertile. I think based upon the literature so far, that might be the case due to obesity or environmental exposures, and more research is needed to definitively answer that question."