Correlation between an absence of cervical gland area on transvaginal sonography and cervical mucus hyaluronic acid levels in women with threatened preterm delivery.

Purpose: Transvaginal sonographic findings of an absent cervical gland area (CGA) and a short cervical length (CL) are frequently observed in patients with threatened preterm delivery. The present study aimed to clarify whether sonographic findings are due to active production of hyaluronic acid (HA) in the cervix. Methods: Possible relationships between sonographic findings of the presence or absence of the CGA and/or a short CL and cervical mucus HA concentration were investigated in 68 women with threatened preterm delivery at 22-31 weeks' gestation and 136 women without threatened preterm delivery as controls. Results: HA levels were higher in women with threatened preterm delivery (68.0 ng/mL) than in controls (39.0 ng/mL; P = 0.001). Similarly, HA levels were higher in women with preterm labor showing an absent CGA and a short CL than in women with threatened preterm delivery without such findings (P < 0.01). Stepwise multivariate logistic regression identified an absent CGA and threatened preterm delivery as independent predictors of high HA levels (P = 0.04). HA concentration was not predictive for preterm delivery. Conclusion: A sonographic finding of an absent CGA reflects high HA levels in the cervix with threatened preterm delivery.