Is the endometrial suction curette useful in the detection of chorionic villi during the first trimester?

Objective: Early diagnosis of ectopic pregnancy is important for its medical management. Algorithms used for the diagnosis of ectopic pregnancy recommend obtaining a tissue diagnosis to rule out an intrauterine pregnancy when it is clear that a pregnancy is abnormal, but a stage of sonographic visualization has not been attained. The ability of an endometrial suction curette to identify products of conception early in pregnancy has not been documented. The purpose of this study was to determine the efficacy of an endometrial suction curette in detecting products of conception during the first trimester.

Methods: Twenty patients scheduled for termination of pregnancy via D&C agreed to endometrial sampling prior to dilatation of the cervix. All patients had transvaginal sonography which verified the gestational age. The specimen was evaluated microscopically after staining.

Results: Chorionic villi were identified in 14 of 20 (70 per cent) specimens as seen with light microscopy.

Conclusion: An endometrial suction curette identifies chorionic villi from an intrauterine gestation in the first trimester with a sensitivity of 70 per cent. While most patients with an intrauterine gestation can be identified using an endometrial suction curette to obtain trophoblastic tissue, the absence of this tissue does not definitively identify an ectopic pregnancy. Therefore, the routine use of the endometrial biopsy in the algorithms for the diagnosis and treatment of ectopic pregnancy should be approached with caution.