Change in periodontitis during pregnancy and the risk of pre-term birth and low birthweight.

Aim: Determine whether periodontitis progression during pregnancy is associated with adverse birth outcomes.
Methods: We used clinical data and birth outcomes from the Obstetrics and Periodontal Therapy Study, in which randomly selected women received periodontal treatment before 21 weeks of gestation (N=413) or after delivery (410). Birth outcomes were available for 812 women and follow-up periodontal data for 722, including 75 whose pregnancies ended <37 weeks. Periodontitis progression was defined as >or=3 mm loss of clinical attachment. Birth outcomes were compared between non-progressing and progressing groups using the log rank and t tests, separately in all women and in untreated controls.
Results: The distribution of gestational age at the end of pregnancy (p>0.1) and mean birthweight (3295 versus 3184 g, p=0.11) did not differ significantly between women with and without disease progression. Gestational age and birthweight were not associated with change from baseline in percentage of tooth sites with bleeding on probing or between those who did versus did not progress according to a published definition of disease progression (p>0.05).
Conclusions: In these women with periodontitis and within this study's limitations, disease progression was not associated with an increased risk for delivering a pre-term or a low birthweight infant.