David Shalowitz, MD, MSHP, explains takeaways from ACOG's guidance on postmenopausal bleeding

On April 16, the American College of Obstetricians and Gynecologists (ACOG) released updated clinical guidance recommending that most patients presenting with postmenopausal bleeding undergo both transvaginal ultrasonography and endometrial tissue sampling as part of the initial evaluation. The update, later highlighted at the 2026 American College of Obstetricians & Gynecologists Annual Clinical & Scientific Meeting, was discussed by David Shalowitz, MD, MSHP, gynecologic oncologist and presenter of the session, “The Latest and Greatest Guidance Updates.”^1,2

The revision marks a shift from prior recommendations that allowed transvaginal ultrasound alone—particularly when endometrial thickness was 4 mm or less—to rule out malignancy in select patients. ACOG notes that approximately 90% of patients diagnosed with endometrial cancer present with postmenopausal bleeding, defined as bleeding occurring 12 or more months after the final menstrual period, underscoring the importance of early and accurate evaluation.

“The key update in the clinical practice update published recently by the American College of Obstetricians and Gynecologists is that for most patients who present with postmenopausal bleeding, both transvaginal ultrasound as well as endometrial biopsy are recommended together as part of the first initial evaluation for that symptom,” Shalowitz said. “The reason that the guidance was updated was, first of all, the incidence and mortality associated with endometrial cancer in the United States has increased over the last two decades, one to 2% per year, and statistically speaking, the accuracy that we previously quoted in earlier versions of this clinical guideline depended on older estimates of prevalence,” he said.

ACOG cites evidence that ultrasound alone may be insufficiently sensitive in ruling out cancer at initial presentation. “At the moment, the potential false negative rate of an ultrasound showing an endometrial thickness of four millimeters or less may be between 5% and 12%, which is unacceptably low for ensuring that patients are accurately counseled about their underlying risk of cancer,” Shalowitz said.

Concerns also extend to diagnostic blind spots in higher-risk populations. “In addition, we're finding that the patients who are most susceptible to underdiagnosis are patients who are more likely to develop cancers of the endometrium that show up as a thin endometrial thickness, and those patients in particular are disadvantaged by relying on ultrasound to rule out cancer based on a thin endometrial lining,” he said.

System-level delays further strengthen the case for a combined approach.

“Finally,” he continued, “we're becoming much more aware of the fact that systems of care play a critical role in getting patients to the clinicians that are able to provide the care that they need, and although previous recommendations did stipulate that if patients had recurrent or continuous postmenopausal bleeding, even after an otherwise reassuring ultrasound, they needed to re-present for care. We're finding that with shortages of clinicians who are able to accurately and adequately assess patients with postmenopausal bleeding in the United States, there's a significant delay associated with diagnosis,” Shalowitz said.

“So the dual approach of ultrasound plus endometrial biopsy allows us to ensure that patients don't go too long and don't have delays that could end up increasing their risk of mortality from this malignancy,” he concluded.

References:

1. Fitch J. ACOG updates guidance for evaluating postmenopausal bleeding. Contemporary OB/GYN. Published April 17, 2026. Accessed May 19, 2026. https://www.contemporaryobgyn.net/view/acog-updates-guidance-for-evaluating-postmenopausal-bleeding
2. Shalowitz, D. ACOG: The Latest and Greatest Guidance. Session. Presented at: American College of Obstetricians & Gynecologists Annual Clinical & Scientific Meeting. May 1-3, 2026. Washington, D.C.