Gingival changes during pregnancy: III. Impact of clinical, microbiological, immunological and socio-demographic factors on gingival inflammation

Aims: To identify predictor variables involved in exacerbated gingival inflammation associated with pregnancy. Material and Methods: In this cohort study, 48 pregnant and 28 non-pregnant women without periodontitis were included. The pregnant women were evaluated in the first, second and third trimester and at 3 months postpartum, whilst the non-pregnant women were evaluated twice, with a 6-month interval. At each visit, clinical [plaque index (PlI) and gingival index (GI)], hormonal (salivary progesterone and estradiol), immunological [gingival crevicular fluid interleukin-1 beta, interleukin-6, tumour necrosis factor-alpha (TNF-alpha) and prostaglandin-E-2] and microbiological (periodontal pathogens culture) evaluations were performed. Statistical analysis was undertaken using exhaustive chi-square automatic interaction detection (exhaustive CHAID) to analyse the predictive value of the independent outcomes to develop pregnancy GI. Results: PlI was the strongest predictor implicated in the GI throughout pregnancy and after delivery. During the second and third trimesters the presence of Porphyromonas gingivalis significantly contributed to the worsening of gingival inflammation. When compared with the non-pregnant group, significant differences were found in TNF-alpha amounts and concentrations and in the third trimester site-specific GI. Conclusions: Bacterial challenge to the gingival tissues, both quantitatively (PlI) and qualitatively (harbouring P. gingivalis) appears to affect the level of gingival inflammation observed during pregnancy.