Association between periodontitis and low birth weight: a case-control study

To verify a possible association between periodontitis and low-birth-weight babies.

One hundred and fifty-one mothers were examined. The case group included 76 mothers (mean age 25.6 years), whose babies at birth weighed <2500 g and had a gestational age (GA) <37 weeks, while 75 mothers (mean age 24.4 years), whose babies were born with a weight of >2500 g and with a GA>37 weeks, were the control group. Data from the mothers and the babies were collected from the Hospital registration records and during an interview with the mother. The periodontal examination included measurements of probing pocket depth (PPD) and clinical attachment loss (CAL) in six sites from all existing teeth, except for third molars. Mothers with periodontitis had at least four sites with PPD> or =4 and CAL> or =3 mm, while healthy mothers had PPD< or =3 mm and CAL< or =1 mm.

The median number of sites with PPD> or =4 and CAL> or =3 mm was eight in the case group, and four in the control group. The significant associations with low birth weight (LBW) babies were periodontitis (odds ratio (OR)=3.48, 95% confidence interval (CI): 1.17; 10.36), arterial hypertension (OR=9.65, 95% CI: 2.22; 41.91), haemorrhage during pregnancy (OR=10.88, 95% CI: 1.95; 60.53), number of pre-natal examinations (OR=0.10, 95% CI: 0.02; 0.43) and genitourinary infection (OR=3.21, 95% CI: 1.25; 8.20).

Periodontitis was considered a risk indicator for LBW in this sample, similar to other risk factors already recognized by obstetricians.