ABSTRACT
<p><b>OBJECTIVE</b>To investigate the relationship between recurrent spontaneous abortion (RSA) and the level of interferon-γ (IFN-γ) and interleukin-4 (IL-4) in peripheral blood and gingival crevicular fluid of patients with chronic periodontitis.</p><p><b>METHODS</b>Fifty pregnant women with recurrent spontaneous abortion (gestational age: 5 - 28 weeks) and 40 pregnant women (gestational age: 39 - 41 weeks) were included and their periodontal status was examined. The level of IFN-γ and IL-4 in gingival crevicular fluid and peripheral blood was detected by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>Nine RSA women and 5 in control group had periodontitis. The prevalence of periodontitis in RSA group was 18% (9/50) and 13% (5/40) in the control group (P < 0.05). The probing depth, attachment loss and bleeding index in RSA group were higher than those in the control group (P < 0.05). The level of IFN-γ was (52.98 ± 17.56) ng/L in gingival crevicular fluid of RSA group and (25.25 ± 7.93) ng/L in control group (P < 0.01). The level of IL-4 was (15.43 ± 1.77) ng/L in gingival crevicular fluid of RSA group and (19.62 ± 4.04) ng/L in control group (P < 0.01). The content of IFN-γ was (27.79 ± 3.59) ng/L in peripheral blood of RSA group and (18.39 ± 2.65) ng/L in control group (P < 0.05). The content of IL-4 was (15.88 ± 0.95) ng/L in peripheral blood of RSA group and (22.98 ± 4.30) ng/L in control group (P < 0.001). The content of cytokines in gingival crevicular fluid and peripheral blood in the same group was positively related (r > 0.8, P < 0.001).</p><p><b>CONCLUSIONS</b>Pregnant women of RSA have a higher chance of getting periodontitis. The change in the level of cytokines in periodontal tissue could result in excursion of maternal intrauterine immune environment to T-helper 1 (Th1). Periodontitis was related to RSA.</p>