Dynamic collagen changes in cervix during the first trimester and decreased collagen content in cervical insufficiency

Objective: To determine the changes in cervical collagen during the first trimester of pregnancy and to evaluate the collagen deficit in cases with a previous diagnosis of cervical insufficiency (CI). Materials and methods: Cervical punch biopsies were obtained from 66 patients divided into three groups: patients with recurrent abortions due to CI (CI group; n = 8); first-trimester abortion group (study group; n = 37), subdivided into three groups according their gestational week (57, 7-9 and 9-12 weeks), and patients with cervical biopsy due to gynecologic reasons (control group; n = 12). Collagen quantity was determined by a biochemical method that measured the levels of hydroxyproline (HOP) in dry cervix tissue. Results: The HOP concentrations were significantly higher at lower gestational ages (p = 0.001). Collagen quantity was lowest in the CI group compared with other groups (p<0.001). Conclusion: This study shows collagen component of cervix decreases as pregnancy advances through the first trimester. Cervical collagen concentration is lower in women with a history of CI compared to controls who has not a history of CI.