  
 re-term
and low-weight babies enter a different world from normal
newborns. "Preemies" begin their lives in a world
populated with incubators to keep them warm, ventilators
to help them breathe. Often, the infants are subjected to
phototherapy, a special light that bathes their body to
metabolize a reddish-yellow pigment that can cause
jaundice.
The vessels
of preemies are so fragile that brain-bleeding is
possible, and infection is a constant risk. These are only
some of the dangers. And working to avert them has a price
tag: when a premature baby is admitted to a neonatal
intensive care unit, it costs an average of $30,000 more
than if the baby were healthy.
Nationally,
an average of 12 percent of births are pre-term, and 8
percent of infants born have a low birth weight. In
Kentucky, more than 4,000 infants are premature each year.
Prematurity—which has increased by 27 percent in the
United States since 1981—is the leading cause of death in
this country within the first month of life.
Why some
women cannot carry to full-term is not always clear.
 octors
will tell you that the cause of low-weight births may be
biological, chemical, genetic, or a combination of
factors. At the University of Kentucky, researcher Jeffrey Ebersole, associate dean for research in the College of
Dentistry, believes there may be another cause:
periodontal disease.
 In
previous studies, researchers found that expectant mothers
with periodontal disease may have a three- to seven-times
greater risk of giving birth to premature and low-weight
babies, and these findings made Ebersole want to
investigate this possible link.
While
important, findings from these studies are only
"associational," he says, and do not prove cause and
effect. "There are little data distinguishing whether the
two problems are linked by causation or due to the same
underlying risk factors," says Ebersole, who also serves
as director of UK's Center for Oral Health Research. Now,
backed by a five-year, $3.3 million grant from the
National Institutes of Health, he is working to find a
link between periodontal disease and low-weight babies.
"Our goal is simple: we want to help make it possible for
mothers to give birth to healthy, normal babies."
In trying to
establish this cause/effect connection, Ebersole first
needs to understand the cause of periodontal disease, an
inflammatory condition of the gums and bone supporting the
teeth that can ultimately lead to an erosion of the gums
and the loss of teeth, so he's starting with bacteria that
live in the mouth.
As far as
bacteria are concerned, the mouth, home for more than 400
types of bacteria, is the perfect host. Some of these
bacterial guests are good guys that live in the mouth
symbiotically and play a part in defending the body
against infection by harmful bacteria. Other bacteria
could kill us and—if they found their way via the
bloodstream superhighway to other parts of the body, such
as the brain, liver and heart—they would.
Under
certain circumstances, the harmful bacteria may cause
periodontal disease. But precisely which factors trigger
bacteria to cause this disease is still a scientific
mystery, Ebersole says.
"For
decades, there appeared to be an easy answer: If you
didn't brush your teeth, you'd get periodontal disease.
But we now know that this answer is generally wrong," he
says.
"There's no
doubt that if you brush your teeth and floss, you will
improve the health of your gums. But there is clearly a
portion of the population that has very poor oral hygiene
and yet does not get periodontal disease. There is also
evidence that some people can take very good care of their
teeth—brushing and flossing—and still get this disease. So
it's not just a matter of the amount of bacteria in the
mouth."
In trying to
solve the mystery of periodontal disease, scientists
become detectives. First, they identify potential
suspects—individual bacteria—and examine them to determine
their possible relationship with the disease. In this work
researchers aren't starting from scratch. By now, the
usual suspects in periodontal disease have been implicated
in an array of medical problems.
Secondly,
scientists are looking at known accomplices such as
inflammation and genetics. The researchers hope these
investigations will help them discover what causes
periodontal disease, an important step to prove the
further cause and effect between the disease and the
incidence of pre-term and low-birth weight infants. |
