Cervical length in uncomplicated pregnancy: A study of sociodemographic predictors of cervical changes across gestation

OBJECTIVE: We conducted this study to evaluate sociodemographic factors associated with changes in the length of the cervix across gestation in pregnancies that resulted in term deliveries. STUDY DESIGN: This study is an observational cohort design of sonographically determined cervical length measured at 3- to 4-week intervals in 125 women with a singleton pregnancy between 20 and 32 weeks gestation. We developed a structured questionnaire to collect psychosocial and sociodemographic characteristics. We used bivariate analysis, analysis of variance, and regression analysis to study variation in cervical length. RESULTS: Overall, cervical length decreased minimally as gestational age progressed. However, among black women cervical length decreased significantly with increasing gestational age (P =.006). In addition, high psychosocial stress was associated with significantly shorter cervices later in gestation, independent of race (P =.003). Finally, women whose occupations involved skilled manual labor had shorter cervices (P =.02). CONCLUSIONS: Women who are black, under stress, or working as skilled manual laborers demonstrate significant shortening of the cervix during gestation. Given that a shorter cervix predisposes to preterm delivery, our findings provide new insights into the well-described association of these psychosocial and sociodemographic factors with an increased risk of preterm delivery.