307: The association between cervical dysplasia, a short cervix, and preterm birth

Abstract

ObjectiveTo determine whether cervical dysplasia in the absence of a cervical excisional procedure is associated with an increased risk of preterm birth (PTB) and whether that risk is explained by an increased risk of a short cervix.Study DesignThis is a cohort of women with a singleton pregnancy who underwent routine cervical length (CL) assessment between 18 and 23 6/7 weeks of gestation from December 2010 until January 2014 and had available delivery records. Women were stratified according to prior dysplasia (i.e., no prior dysplasia, prior dysplasia but no excisional procedure, or prior excisional procedure). The frequencies of a short cervix (CL ≤ 2.5cm) and PTB were compared between groups and backward elimination multivariable analyses were performed to identify whether (1) dysplasia alone or a prior excisional procedure were associated with PTB and (2) whether these factors remained independent risk factors for PTB after controlling for the presence of a short cervix.ResultsOf the 18,528 women who met inclusion criteria, 3023 (16.3%) had a history of dysplasia without an excisional procedure and 1356 (7.3%) had a prior cervical excisional procedure. The incidence of a short cervix for women without dysplasia, with dysplasia alone, or with a prior excisional procedure was 0.8%, 1.0%, and 2.2%, respectively (p<0.001). The incidence of PTB, respectively, was 6.4%, 6.5%, and 8.4% (p<0.001). After adjusting for potential confounding factors, prior excisional procedure but not dysplasia alone was associated with PTB (Table). This relationship persisted after adjusting for the presence of a short cervix. Interaction terms were non-significant and demonstrated that a short cervix conveyed similar increased risk for PTB regardless of a woman’s dysplasia or excisional procedure history.ConclusionHaving a prior cervical excisional procedure but not dysplasia alone is associated with an increased risk of PTB. This association is independent of the finding of a short cervix.Regression 1: adjustment for race, IVF conception, parity, prior preterm birth, and prior dysplasia historyRegression 2: adjustment for factors from regression 1 + short cervixRegression 3: adjustment for factors from regression 2 + interaction terms ObjectiveTo determine whether cervical dysplasia in the absence of a cervical excisional procedure is associated with an increased risk of preterm birth (PTB) and whether that risk is explained by an increased risk of a short cervix. To determine whether cervical dysplasia in the absence of a cervical excisional procedure is associated with an increased risk of preterm birth (PTB) and whether that risk is explained by an increased risk of a short cervix. Study DesignThis is a cohort of women with a singleton pregnancy who underwent routine cervical length (CL) assessment between 18 and 23 6/7 weeks of gestation from December 2010 until January 2014 and had available delivery records. Women were stratified according to prior dysplasia (i.e., no prior dysplasia, prior dysplasia but no excisional procedure, or prior excisional procedure). The frequencies of a short cervix (CL ≤ 2.5cm) and PTB were compared between groups and backward elimination multivariable analyses were performed to identify whether (1) dysplasia alone or a prior excisional procedure were associated with PTB and (2) whether these factors remained independent risk factors for PTB after controlling for the presence of a short cervix. This is a cohort of women with a singleton pregnancy who underwent routine cervical length (CL) assessment between 18 and 23 6/7 weeks of gestation from December 2010 until January 2014 and had available delivery records. Women were stratified according to prior dysplasia (i.e., no prior dysplasia, prior dysplasia but no excisional procedure, or prior excisional procedure). The frequencies of a short cervix (CL ≤ 2.5cm) and PTB were compared between groups and backward elimination multivariable analyses were performed to identify whether (1) dysplasia alone or a prior excisional procedure were associated with PTB and (2) whether these factors remained independent risk factors for PTB after controlling for the presence of a short cervix. ResultsOf the 18,528 women who met inclusion criteria, 3023 (16.3%) had a history of dysplasia without an excisional procedure and 1356 (7.3%) had a prior cervical excisional procedure. The incidence of a short cervix for women without dysplasia, with dysplasia alone, or with a prior excisional procedure was 0.8%, 1.0%, and 2.2%, respectively (p<0.001). The incidence of PTB, respectively, was 6.4%, 6.5%, and 8.4% (p<0.001). After adjusting for potential confounding factors, prior excisional procedure but not dysplasia alone was associated with PTB (Table). This relationship persisted after adjusting for the presence of a short cervix. Interaction terms were non-significant and demonstrated that a short cervix conveyed similar increased risk for PTB regardless of a woman’s dysplasia or excisional procedure history. Of the 18,528 women who met inclusion criteria, 3023 (16.3%) had a history of dysplasia without an excisional procedure and 1356 (7.3%) had a prior cervical excisional procedure. The incidence of a short cervix for women without dysplasia, with dysplasia alone, or with a prior excisional procedure was 0.8%, 1.0%, and 2.2%, respectively (p<0.001). The incidence of PTB, respectively, was 6.4%, 6.5%, and 8.4% (p<0.001). After adjusting for potential confounding factors, prior excisional procedure but not dysplasia alone was associated with PTB (Table). This relationship persisted after adjusting for the presence of a short cervix. Interaction terms were non-significant and demonstrated that a short cervix conveyed similar increased risk for PTB regardless of a woman’s dysplasia or excisional procedure history. ConclusionHaving a prior cervical excisional procedure but not dysplasia alone is associated with an increased risk of PTB. This association is independent of the finding of a short cervix.Regression 1: adjustment for race, IVF conception, parity, prior preterm birth, and prior dysplasia historyRegression 2: adjustment for factors from regression 1 + short cervixRegression 3: adjustment for factors from regression 2 + interaction terms Having a prior cervical excisional procedure but not dysplasia alone is associated with an increased risk of PTB. This association is independent of the finding of a short cervix.