A Possible Explanation of the Decline in Birth Rate Among "Adolescent and Young Teen Girls

James Michael Howard jmhoward at anthropogeny.com
Tue Nov 16 09:49:03 EST 2004

A Possible Explanation of the Decline in Birth Rate Among "Adolescent
and Young Teen Girls in the United States" as Well as Other Groups

Copyright 2004, James Michael Howard, Fayetteville, Arkansas, U.S.A.

The birth rate of "adolescent and young teen girls in the United
States" has declined to the lowest levels since 1946.  The
explanations include abstinence programs and birth control.  Well,
this combination may be the reason and this would be positive because
it can be continued.  However, there may be another reason for this
decline in birth rate.

It is my hypothesis that the "secular trend," the increase in size and
earlier puberty occurring in our children results from increases in
testosterone.  That is, the percentage of people of higher
testosterone is increasing more rapidly than those of lower
testosterone.  (Testosterone, not estrogen, is the source of sexual
activity in girls and women.)  Over time the percentage of individuals
of higher testosterone increases within the population.  This is
driven by the percentage increase in women of higher testosterone and
the consequences of this are due to exposure of fetuses to higher
maternal testosterone.  The neonates become children who grow bigger
and enter puberty earlier, among other phenomena that are also
increasing within our population.

If individuals of higher testosterone are increasing in percentage and
this is the cause of reduced birth rates, then increased testosterone
should be connected with reduced fertility and conception in women and
girls.  This is supported.

In this citation, note the effects of testosterone on fertility "in
the absence of clinical signs of hyperandrogenism.  In other words,
increased testosterone may reduce fertility in women and girls without
outward signs of excessive testosterone.  "The mean level of free T
[testosterone] was significantly higher (P less than 0.05) in
anovulatory women when compared with ovulatory ones. 
The results show
that in infertile women determination of androgen levels, and
especially free T [testosterone], is indicated in the absence of
clinical signs of hyperandrogenism." (Human Reproduction 1988; 3:

This next citation supports, again, that high testosterone reduces
conception.  "In addition, levels of free testosterone during the
follicular phase were significantly lower in women who conceived
compared to non-conceptional IVF cycles, whereas levels of total
testosterone were similar." (Human Reproduction 1992; 7: 1365-70).

This effect does not affect women alone.  Too much testosterone
reduces spermatogenesis, sperm count, in men.   Testosterone
undecanoate increases free testosterone in men.  "Monthly injections
of testosterone undecanoate (TU) act as a male contraceptive by
reversibly suppressing spermatogenesis to azoospermia or severe
oligoazoospermia in 95% of Chinese men." (Journal of Andrology 2004;
25: 720-7)  I suggest the secular trend, the increase in testosterone,
is also affecting men.  This effect may be linear, that is, sperm
count may begin to be reduced at a high level of testosterone before
actually causing spermatogenesis to cease.  I think this is occurring
with the secular trend.

Again, I suggest the secular trend, which is real and robust in our
children ("Secular Trends in Height Among Children During 2 Decades,"
(Archives of Pediatric and Adolescent Medicine 2000; 154: 155-161),
represents an increase in individuals of higher testosterone.  As this
increase occurs, we increasingly see the effects of excessive
testosterone.  I suggest one of these effects is a reduction in birth
rates of individuals of high testosterone because high testosterone
reduces fertility / conception in females and reduces sperm count in
males.  This may be the cause the decline in teenage birth rates.

Now, as I stated above, the institution which reported these findings
regarding teenage birth rates suggested that abstinence programs and
contraception may be producing this effect.  If I am correct, then we
should be seeing other consequences of increasing testosterone within
our population that should not be ameliorated by abstinence programs
or contraception.  Autism has been connected with maternal
testosterone levels and autism is also increasing within our
population.  Testosterone levels have been directly connected with
breast cancer.  "
testosterone might be more strongly associated with
[breast cancer] risk than estradiol." ( Journal of the National Cancer
Institute (U.S.A.) 2002; 94: 606-616).  Breast cancer is rapidly
increasing and has been determined to not be due to increased
surveillance.  I also suggest a strong case may be made for the
involvement of excessive testosterone with obesity, premature and
underweight births, and learning problems, all of which are

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