A CDC scientist analyzed international trends in the
rates of two birth defects that can affect males: hypospadias and
cryptorchidism.
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Hypospadias is a birth defect characterized by the
urethral opening not being correctly located at the tip of the
penis. The urethral opening is usually located closer to the body on
the ventral side of the penis in a boy with hypospadias. Surgery is
often required.
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Cryptorchidism is when one or both of the testes
have not descended into the scrotum by the time a full term infant
is born. If it persists it can require surgery.
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Researchers from seven European nations and the
United States have published reports of increasing rates of
hypospadias during the 1960s, 1970s, and 1980s. Reports of
increasing rates of cryptorchidism have come primarily from England.
In the 1990s, these reports have become one focus of the debate over
endocrine disruption.
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This study examines more recent data from a larger
number of countries to determine whether such increases are
worldwide and continuing and whether the increases show any
geographic patterns.
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The International Clearinghouse of Birth Defects
Monitoring Systems and individual systems provided the data.
Countries were categorized into rough quintiles by gross domestic
product in 1984.
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Hypospadias increases were most marked in two U.S.
systems and in Scandinavia and in Japan. The increases leveled off
in many systems after 1985. Increases were not seen in less affluent
nations.
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Cryptorchidism rates were available for 10
systems. This anomaly clearly increased in two U.S. systems and in
the South American system but not elsewhere. Since 1985, rates have
declined in most systems.
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Better diagnosis, more complete reporting, and
better surveillance systems may have contributed to or caused the
upward trends in hypospadias. Possible real causes include
demographic changes and endocrine disruption.
