The effect of antepartum periodontal therapy on preterm birth rate according to cervical length: A randomized pilot study

Abstract

RATE ACCORDING TO CERVICAL LENGTH: A RANDOMIZED PILOT STUDY SARAH SMITH, ROBERT STRAUSS, STEVEN OFFENBACHER, KEVIN MOSS, KIM BOGGESS, SALLY TIMLIN, JAMES BECK, University ofNorthCarolina atChapel Hill, Obstetrics/Gynecology, Chapel Hill, North Carolina, University ofNorth Carolina at Chapel Hill, Center for Oral and Systemic Diseases, Chapel Hill, North Carolina, University of North Carolina at Chapel Hill, Dental Ecology, Chapel Hill, North Carolina, WakeMed, Obstetrics/Gynecology, Raleigh, North Carolina OBJECTIVE: To determine if cervical length affects the impact of antepartum periodontal therapy on preterm birth rate. STUDY DESIGN: This was a randomized controlled pilot study to determine the effect of antepartum periodontal therapy on preterm birth risk among women at high risk for preterm birth (prior spontaneous PTB). Women with periodontal disease identified at dental screening visit !16 weeks were randomized to antepartum periodontal therapy. The antepartum intervention group received periodontal scaling and root planning at 16-20 weeks gestation followed by use of a Sonicare-Plus power toothbrush with oral health instructions the remainder of the pregnancy. The control group received a manual toothbrush without oral health instructions. At 22 weeks’ gestation, participants underwent a transvaginal ultrasound for cervical length measurement. The primary outcome was preterm delivery !37 weeks. RESULTS: Baseline characteristics including cervical length of the 31 women in the periodontal intervention group and the 32 women in the control group were similar, except for baseline periodontal pockets which were unbalanced after randomization. Among women with a cervical length !30 mm, preterm delivery was similar between the control and intervention groups (50% versus 38%, P=0.66). Compared to women with a cervical length 30 mm, preterm delivery was also similar between the control and intervention groups (41% versus 22%, P=0.17). However, after adjusting for the baseline imbalance in periodontal disease among women with a cervical length 30 mm, periodontal therapy significantly decreased the odds of preterm delivery (OR=0.12; 95% CI 0.02-0.78). For women with cervical length !30 mm the intervention did not reach significance (OR= 0.61; 95% CI 0.09-4.13). CONCLUSION: In women with periodontal disease at the beginning of pregnancy, periodontal treatment may be more effective in preventing preterm delivery among women with normal cervical length compared to women with shortened cervix.