Pregnant women with gum disease are much more likely to bear dangerously small babies, adding to evidence that various kinds of infections may provoke premature births, researchers say.
Reproductive and urinary-tract infections have been known to play a role in early births, but a study released Tuesday is the first to link periodontal disease with the problem, researchers said.
Significant gum disease is rare in women under 35, said the lead researcher, Dr. Steven Offenbacher, a periodontics professor at the University of North Carolina’s School of Dentistry in Chapel Hill.
Since most of the 124 women in the study were in their early 20s, Offenbacher speculated that poor dental hygiene or dental care - frequent culprits in gum disease - may offer only a partial explanation.
Young women with gum disease who give birth prematurely may have weak immunity and may react to infections in biologically unusual ways that induce early labor, he said by telephone Monday.
The study is published in a supplement to The Journal of Periodontology. Findings were released Tuesday in New Orleans at the annual meeting of the Chicago-based American Academy of Periodontology.
Experts not associated with the study expressed caution, especially since a small number of women were involved and most were enrolled and examined after they had given birth.
“It’s a hypothesis-generating study: It doesn’t prove anything, but it certainly gives a lot of food for thought,” said Dr. Robert L. Goldenberg, chairman of obstetrics-gynecology at the University of Alabama, Birmingham.
“What we know is that women who have an infection anywhere in their bodies release a whole cascade of molecules that potentially could initiate labor, and whether they do or not is not proven by any means, but that’s a very interesting area of study right now,” Goldenberg said.
Each year, more than 250,000 infants - about 10 percent of the total - are born early and weigh less than 5 pounds, 8 ounces, researchers noted.
Such low-birthweight babies account for most infant deaths in the United States. Low-birthweight babies often struggle with respiratory distress syndrome, anemia, jaundice, mental retardation, cerebral palsy or other problems.
Researchers studied 93 women who gave birth prematurely to underweight babies, and 31 who had normal babies. The prevalence of gum disease was not given in numbers, since each woman was given a score reflecting periodontal health.
Using those scores, researchers calculated that women with gum disease were more than seven times as likely to give birth prematurely as women with healthy gums. The researchers controlled for other traits that can cause premature births, such as smoking, alcohol consumption and prenatal care.
If the link is borne out by further studies, the researchers speculated that up to 18 percent of premature births may be attributable to gum disease, a proportion comparable to the share caused by smoking.