Prevalence and clinical effect of caesarean scar defects in women undergoing IVF.

RESEARCH QUESTION: How common are caesarean scar defects (isthmocele) among patients who have had previous caesarean delivery undergoing IVF for secondary infertility? Does the presence of isthmocele affect the chances of success of IVF? DESIGN: In this cohort study, women referred to an Italian public assisted reproduction centre between January 2016 and April 2021 were retrospectively reviewed. Women with a history of caesarean delivery and an indication for IVF were selected. On the basis of the local policy, all patients with a history of caesarean section underwent saline contrast sonography (SCS). Sonographic evaluation was standardized. RESULTS: One hundred and forty-four women were eligible, of whom 22 declined SCS and eight decided to delay pregnancy seeking. Overall, 114 women were available for data analysis. Seventy-six women were diagnosed with caesarean scar defects, corresponding to a prevalence of 67% (95% CI 58 to 75%). Baseline characteristics of women with and without isthmocele were similar. Conversely, the clinical pregnancy rate (adjusted OR 0.31, 95% CI 0.13 to 0.72) and live birth rate (adjusted OR 038, 95% CI 0.17 to 0.86) were significantly lower among affected women. No associations between specific sonographic defect characteristics and IVF outcome could be identified. CONCLUSIONS: Caesarean scar defects are common among women with a history of caesarean section requiring IVF. The presence of these lesions may reduce the chance of success of the procedure.