TOPLINE

Approximately two thirds of cesarean scar ectopic pregnancies managed with watchful waiting progressed to a live birth. However, nearly half of the cases required peripartum hysterectomy. The probability of undergoing hysterectomy increased with decreasing residual myometrial thickness.

METHODOLOGY

• Researchers analyzed data from an international registry on cesarean scar ectopic pregnancies, assessing associations with the risk for peripartum hysterectomy.
• They analyzed data from 115 cases that were managed expectantly beyond the first trimester, retrieved from 21 centers across 13 countries between 2018 and 2023.
• Diagnosis of cesarean scar ectopic pregnancy was established using transvaginal ultrasonography, with criteria including anterior implantation of the gestational sac within the previous scar or niche, with peritrophoblastic or periplacental vascularity assessed using color Doppler examination.
• Researchers measured first-trimester residual myometrial thickness at the thinnest part of the myometrium, from the top of the cesarean scar niche to the serosal surface.
• Data collection involved ultrasound results from each trimester, occurrences of hysterectomy around delivery, and histopathologic results.

TAKEAWAY

• In total, 67% of cases resulted in live birth, and 43.5% required peripartum hysterectomy; 33% resulted in pregnancy loss between 13 and 29 weeks of gestation, of which 55.3% were spontaneous.
• Residual myometrium in the first trimester was significantly thinner in the hysterectomy group than in the non-hysterectomy group (median, 2 mm vs 4.8 mm; P = .004).
• Enhanced subplacental vascularity in the scar area was more frequent in the hysterectomy group than in the non-hysterectomy group (86.2% vs 59.1%; P = .04).
• A first-trimester residual myometrial thickness < 2.5 mm led to the identification of 80% of women who required peripartum hysterectomy with 64% sensitivity, 75% specificity, and 76% positive predictive value; the probability of undergoing hysterectomy increased as the residual myometrial thickness decreased (P = .001).

IN PRACTICE

“These findings underscore the importance of precise ultrasound assessment in the early detection and management of cesarean scar ectopic pregnancy. Integrating residual myometrial thickness into routine screening and incorporating multidisciplinary decision-making will be essential in optimizing maternal and fetal outcomes in this complex condition,” the authors of the study wrote.

SOURCE

The study was led by Andrea Kaelin Agten, Corniche Hospital, Abu Dhabi, United Arab Emirates. It was published online on June 4, 2026, in the American Journal of Obstetrics and Gynecology.

LIMITATIONS

The dataset only included cases of cesarean scar ectopic pregnancy that were managed expectantly and resulted in live birth and lacked information on blood loss and transfusion rates. The results may not apply to all cesarean scar ectopic pregnancies because the cohort consisted of a specific subgroup of women who chose to continue their pregnancies despite knowing the risks and declined termination.

DISCLOSURES

The registry received funding through unrestricted grants from the Freiwillige Akademische Gesellschaft, Basel, and the Gottfried und Julia Bangerter-Rhyner-Stiftung. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.