Objective
Cesarean scar pregnancy (CSP) refers to the abnormal implantation of the gestational sac in the area of the previous cesarean delivery (CD) scar, potentially leading to life-threatening complications, including uterine rupture and the development of placenta accreta spectrum (PAS) disorders. , The short-term risk of women with CSP, mainly that of uterine rupture, is difficult to predict, and there is currently no reliable ultrasound marker to predict such risk, thus making prenatal counseling challenging. This study aimed to ascertain whether early ultrasound assessment can predict the risk of uterine rupture in women with CSP.
Study Design
This was a cohort study of women with a prenatal diagnosis of CSP at 6 to 8 weeks of gestation since the introduction of a national screening program for CSP in Italy. We tested the hypothesis that the severity of CSP, defined using either the “crossover” sign (COS) or “in-the-niche vs on-the-scar” classification ( Figure ), can predict the risk of uterine rupture, defined as a full-thickness disruption of the uterine wall that also involves the overlying visceral peritoneum, in the first or early second trimester of pregnancy. Ultrasound assessment of both COS and “in-the-niche or on-the-scar” implantation was carried out by 2 different researchers (G.C. and F.D.A.) experienced in the prenatal diagnosis and management of such anomalies blinded to the clinical outcome.
Results
The analysis included 119 women with a prenatal diagnosis of CSP. There was an agreement in the labeling of all CSP images regarding the type of “COS” and “in-the-niche or on-the-scar” classification between the 2 researchers ( Table ). Uterine rupture occurred in 7.6% of women, whereas 92.4% of women experienced uterine rupture in the third trimester of pregnancy and were all found to have PAS. There was no significant difference in maternal age ( P =.744), parity ( P =.842), and number of previous CDs ( P =.633) between pregnancies complicated by uterine rupture and pregnancies not complicated by uterine rupture. All cases complicated by uterine rupture showed COS1 or “in-the-niche” insertion of the gestational sac, but only 13% to 14% of cases showed COS2 or “on-the-scar” insertion of the gestational sac ( P <.001 for both). In multivariate logistic regression analysis, only COS1 (odds ratio [OR], 83.64; 95% confidence interval [CI], 6.80–1033.62; P <.001) and “in-the-niche” insertion (OR, 28.22; 95% CI, 4.6–172.7; P <.001) were significantly associated with the risk of uterine rupture.
