Adam L. Beberg
Thu, 18 Apr 2002 19:18:55 -0700 (PDT)
Since we're on the topic of chemicals and mutant frogs...
They found a way to get asians to stop smoking :)
On a biological basis, harsher conditions of any kind should favor the
allocation of resources to females of course, dah. Tho the facts that we are
animals and that smoking is dangerous are both still unknown to modern
- Adam L. "Duncan" Beberg
Couples Wanting Baby Boy Should Not Smoke
Thu Apr 18, 7:08 PM ET
By Patricia Reaney
LONDON (Reuters) - Couples wanting to conceive a boy should not smoke,
New research reported by Japanese and Danish scientists in The Lancet
medical journal on Friday showed that couples who smoked around the time
their child was conceived were less likely to have a son.
"If the father smokes more than 20 cigarettes a day and the mother does not
smoke the sex ratio is significantly decreased with fewer boys than girls,"
Professor Anne Grete Byskov, of University Hospital of Copenhagen, said in
If both parents smoke the chances of producing a male child are even lower.
Byskov and Dr. Misao Fukuda of the Fukuda Ladies Clinic in Hyogo, Japan, who
conducted the study, are not sure why smokers produce fewer boys.
But they suspect that sperm carrying the Y chromosome for male children may
be more susceptible than sperm with the female-forming X chromosome to the
effects of tobacco which could make it less likely to fertilize the woman's
"Smoking may cause a stress effect on the sperm cell itself since the sex
ratio also declined when the mother smoked but not the father," Byskov
Observational studies from Denmark, Britain, the United States, Canada and
other countries have shown a decline in the male to female ratio of children
during the past few decades.
Exposure to toxins such as dioxin, which can affect the male reproductive
system, and stress have been suggested as possible causes.
The scientists studied the smoking patterns around the time of conception of
the parents of 11,800 Japanese infants. The mothers were questioned about
their smoking habits and their partner's.
After dividing the couples into three groups -- non-smokers, less than 20
cigarettes a day smokers and 20 plus a day smokers -- they found that the
male-to-female sex ratio declined with the increased number of cigarettes
smoked by the parents.
It was the highest in the non-smoking group and the lowest among the top
"We suggest that periconceptual smoking (around the time of conception) of
the parents reduces the frequency of conceiving male children," the
scientists said in the study.
A study by Italian scientists of men who had been exposed to dioxin
following an explosion at a chemical plant in 1976 showed they were more
likely to father daughters than sons.