Infant size linked to mother's periodontal disease

NEW YORK (Reuters Health) - The results of a new study suggest that there is an association between periodontal disease during pregnancy and an increased risk that the infant will be born small for gestational age.

"Normal fetal growth is an important indicator of fetal well-being," the authors write in the American Journal of Obstetrics and Gynecology. "Fetal growth restriction complicates 3 percent to 7 percent of all pregnancies, affecting almost 200,000 births annually."

Dr. Kim A. Boggess, of the University of North Carolina, Chapel Hill, and colleagues conducted a study of 1,017 pregnant women. The researchers evaluated the women for periodontal disease and the birth weights of their infants were determined. Infants who weighed less than the 10th percentile for gestational age were considered small for gestational age.

Overall, 6.6 percent of the women delivered a small for gestational age infant. Periodontal status was "healthy" for 28.0 percent of the women, while 57.8 percent had mild periodontal disease and 14.3 percent had moderate to severe periodontal disease.

Women with moderate to severe periodontal disease were significantly more likely to give birth to a small for gestational age infant. The rate of small for gestational age infants was 13.8 percent in women with moderate to severe disease, 6.5 percent in women with mild periodontal disease, and 3.2 percent in women with healthy gums.

The researchers calculated that the risk of delivering a small for gestational age infant was 2.3-time greater than normal among women with moderate to severe periodontal disease.

"The mechanism of periodontal disease-associated adverse pregnancy outcomes remains speculative, but inflammatory responses are likely involved," Boggess and colleagues explain. They suggest that maternal periodontal disease causes a systemic inflammatory response in a subset of women, which results in abnormal placental or fetal development that slows fetal growth.

The investigators also suggest these findings could lead to prenatal treatment that may improve fetal growth.

SOURCE: American Journal of Obstetrics and Gynecology, May 2006.