Sperm Count Down? What's the Problem?? There have been several posts lately about a reported drop in human (male) sperm concentrations. The current (Jan 16, 96) issue of The NEW YORKER has a 12 page article which gives a summary of this situation. Briefly it is this. Several reports, mostly from Denmark, have claimed a recent drop in the concentration of strong viable sperm cells in men. There has been confirmations from studies in Philadelphia and Houston. Other researchers disputed that these reports reflect a "real" drop, but rather a change in the way the data was gathered and evaluated. In 1992, Niels Skakkebaek and his Danish group reviewed all published studies (61) of sperm counts from around the world, going back to 1938. It is not as easy as you might suppose to draw valid conclusions from such data, since there is a large variation between men, and sperm count drops with age. Often those counted are not representative of the population at large. It was suggested that some earlier counts were on men selected as sperm bank donors (thus way above normal) while more recent studies have been on men with fertility problems (thus likely below normal). And age was not recorded in some studies, etc. But included is data from a clinic in Paris which has been using the same counting protocol and procedures for twenty years, so unlike most of the data, this should be meaningful. IN SUMMARY To sum it up: the reported drop MAY be real. I would guess it probably is, but this is not certain. Sperm counts may be down as much as one half their levels of 1940. If real, it is not clear whether it has been gradual or happened suddenly during the 1960's (the cliff model). If real, it is at least as common in Europe as in the US (a point I will return to later). It may vary a lot by region, being minor or not happening at all in Finland and parts of the US but large in Denmark and Paris. It may be happening in Africa, Pakistan, Hong Kong and Germany. Explanations range from tight underwear to riding bicycles to global warming (since sperm count tends to drop with temperature). Those who believe in the drop usually suggest that it may be due to increased low levels of estrogen and/or compounds which mimic estrogen that are now in the environment. These can, even at very low levels, perhaps too low to detect, shut down sperm production in the male fetus. The news recently had an article about a conflict between the US and Europe over the European Union's attempts to stop the import of US beef into Europe. The Europeans claim this is not an attempt to protect European farmers from competition but rather a health issue: US beef is fed estrogen-like compounds to promote growth. But if US cattle have these compounds and European cows do not, it is not consistent with the estrogen explanation that the sperm drop is at least as large in Europe. SO WHAT'S THE PROBLEM?? A typical ejaculation may contain from 60 million to a billion sperm. Only one is needed to fertilize an egg cell. The sperm count would have to fall to much lower levels before it would have an impact on birth rates. Let's consider the "worst" case --or is it the "best" case? What if the sperm drop IS real, and that sperm levels HAVE dropped by 50 % since 1940. And that they continue to drop. So what? Isn't OVERPOPULATION the problem (or potential problem)? Who thinks there are just not enough people in the world? Suppose male sperm levels were to drop so low that fertility clinics were needed for women to get pregnant. This would limit population growth, and could provide a way to insure that children were WANTED and had TWO parents who are able and willing to provide for them before they are conceived. This could mean that child poverty and child neglect would become rare to non-existent. Underpopulation now ranks number 235 on my list of things to worry about, just ahead of "what is going to happen to all those forms with 19___ printed on them when the year 2000 arrives." When the world population falls to 1 billion, it will graduate to my Top Ten. And, for those of you who put any stock in the Gia Theory of the whole earth as a giant organism/feedback mechanism, maybe this is Mother Nature's way of telling us to back off. FALLING SPERM UPDATE After I posted Sperm Count Falling? What's the Problem? (Now on my web page) I saw a TV news report on the topic and TIME had an article in the March 18, 1996 issue. Several replies from the Newsgroup post were interesting. No one suggested that a decline in birth rates would be a serious problem, at least not for a while. jrc@tei.umass.edu pointed out that the end of 19-- and its replacement by 20-- is no laughing matter, and sure enough, soon after an article in USA TODAY estimated a cost of billions of dollars projected to switch over computer software which now thinks 2000 entered is really 1900 since it reads only the last two digits. Do We Suffer from TOO MUCH SEX? Another suggested a cause (assuming there exists something that needs a cause) that had crossed my mind when I read the New Yorker article, but that I set off in a corner. But there could be something to it: what do you think? The idea is this: sperm count is lowered for a while after a man has sex. If men have sex more often now than in the past, the sperm count would be lower. The drop (if real) is thought to have occurred during the late 1960's, maybe down sharply in the late 60's but steady since. Could this be due to men getting more sex since the "pill" ? Are women more willing since then? A consequence of the "sexual Revolution"? That combined with a general change in attitudes could be the cause. And if so, will this be reversed by the concern over AIDS? More Birth Defects? Several replies were concerned that the reduction in number of sperm is associated with more weak, damaged or deformed ones, and that this would lead to more birth defects. If that were a problem, it should be happening now. Recently I attended a talk by Renata Laxova of the UW Department of Medical Genetics. The talk was being picketed by a student group (memories of the 1960's!!). They seemed to oppose the concept of genetic counseling on the grounds that mothers might abort fetuses which had serious genetic disorders. After the talk, I asked if there has been any increase in birth defects. The answer was no change has been noted. My follow up question was: is there enough data (past and present) to know if a change has happened? The answer was "probably not", the change would have had to be very large to be noticed. To a first approximation, more deformed or weakened sperm won't cause more deformed children since they won't have the strength to make the long swim to the egg and fertilize it. And most fertilized eggs that do have serious genetic defects either don't implant or are spontaneously aborted. But whether or not a large increase in damaged sperm result in more or fewer deformed children will depend on societies' attitude/laws concerning genetic counseling and abortion. If genetic testing, counseling and abortion are accepted, there will be a decline in birth defects and congenitally deformed children whether or not there are more damaged sperm. But if the protesting students have their way, there will be MORE deformed kids. This is because advances in medical technology result in saving deformed babies that would have died in the past. They could constitute as many as 3/4 of the future population (See the article "the Politics of Abortion" on my web page). ,,,,,,, ____________________ooo__(_O O_)__ooo_________________________ (_) Jim Blair (jeblair@facstaff.wisc.edu) University of Wisconsin, Madison (USA). For a good time, call http://www.execpc.com/~jeblair/index.html "This message is brought to you using biodegradable binary bits and 100 % recycled bandwidth."