Pregnancy of Unknown Location: The Value of Frozen Section Analysis and Its Relation to Beta-hCG Levels and Endometrial Thickness

Abstract

Objective Frozen section examination is a rapid method for identifying products of conception in endometrial curetting, yet its accuracy is inconclusive. The purposes of this study is to determine the accuracy of frozen section analysis of endometrial curetting in pregnancies of unknown location, and to verify the relation of β-human chorionic gonadotrophin (hCG) level and endometrial thickness to the assessed accuracy. Methods We reviewed data from January 2009 to December 2014 of diagnostic curettages from women with suspected ectopic pregnancies sent for frozen section examination at a medical center. A frozen section diagnosis was considered accurate if it concurred with the final pathologic diagnosis. Results Of 106 frozen section studies, the diagnosis was accurate in 94 (88.7%). Of 79 specimens interpreted as negative on frozen sections (no products of conception noted), 9 (11.4%) were positive on final pathologic review. Three of the 27 (11.1%) specimens interpreted as positive by a frozen section failed to demonstrate products of conception on a final pathologic section. The sensitivity of frozen sections in the diagnosis of ectopic pregnancy was 72.7%, specificity 95.9%, positive predictive value 88.9%, negative predictive value 88.6%, and accuracy 88.6%. A statically significant correlation was found between β-hCG level and high accuracy of the frozen section technique (p < 0.001). No correlation was found between endometrial thickness and the accuracy of the frozen section technique. Conclusion The accuracy of frozen section examination was high and was found to correlate with β-hCG level, but not with endometrial thickness.

Predictive analytical model for ectopic pregnancy diagnosis: Statistics vs. machine learning

“…Particularly interesting for researchers is the new feature, serum hCG cutoff at ≥ 1,000 mL/mL, for predicting EP. Also, another study found similar associations (46). To the best of our knowledge, no model has used this serum cutoff as a feature in prediction, yet.…”

Overview of ectopic pregnancy diagnosis, management, and innovation

“… 24 Frozen section technique is performed on endometrial material shortly after curettage and decreases the time needed to disprove EP diagnosis. 25 Of 106 women who underwent frozen section technique, nine patients with IUP were falsely started on MTX therapy and three patients with EPs were incorrectly diagnosed with IUP and discharged. 25 Concurrent methods for diagnosis are necessary to avoid unwanted pregnancy termination and missed EPs.…”

“… 25 Of 106 women who underwent frozen section technique, nine patients with IUP were falsely started on MTX therapy and three patients with EPs were incorrectly diagnosed with IUP and discharged. 25 Concurrent methods for diagnosis are necessary to avoid unwanted pregnancy termination and missed EPs. Karman cannula aspiration of endometrium allowed 2/3 of women to avoid EP treatment and showed faster recovery times of 12.6 days for IUP when compared to 26.3 days for patients treated with MTX.…”

“…Sensitivity and specificity of endometrial sampling methods.Source: Table modified from Batig et al[24][25][26] …”