Treatment of cervical dysplasia and the risk of preterm birth: understanding the association

Abstract

ver the past decade, there has been an evolution in the One of the key strengths of this study was the incorO screening and management of cervical dysplasia toward a more conservative approach. Accumulating data from large studies demonstrating a low risk of cervical cancer among adolescents and women 21-24 years of age supported these changes. However, a major stimulus for the new guidelines was concern regarding the potential adverse effects of excisional procedures on subsequent pregnancy outcomes, namely, preterm birth. The published evidence overall reflects an increased risk of preterm birth in women with a history of a cervical excisional procedure. However, recent studies have found a similar increased risk for preterm birth in women with cervical dysplasia without a history of cervical excision. This suggests that perhaps cervical excisional procedures do not cause subsequent preterm birth, but rather the risk factors for cervical dysplasia are similar to those for preterm birth. As a result of these recent findings, there has been a renewed interest in clarifying the relationship among cervical dysplasia, excisional procedures, and preterm delivery. Published in this issue of the journal, the study by Miller et al aims to further investigate whether cervical dysplasia without a cervical excisional procedure is associated with an increased risk of preterm birth, and to determine if the possible increased risk can be attributed to the presence of a short cervix. Miller et al conducted a retrospective cohort study including 18,528 pregnant women who underwent routine cervical length screening over the 4-year study period. These women were stratified into 3 groups based on review of medical records: no prior dysplasia, history of dysplasia without cervical excisional procedure, and prior excisional procedure. Using multivariable logistic regression equations, they found that after adjusting for the presence of a short cervix and other potential confounders, a prior excisional procedure (adjusted odds ratio [aOR], 1.31; 95% confidence interval [CI], 1.04e1.64), but not prior dysplasia alone (aOR, 1.02; 95% CI, 0.85e1.21) was associated with preterm birth.