Endometrial Aspiration before or after Saline Infusion Sonography and the Effect on Specimen Quality: A Randomized Study

Study Objective Saline infusion sonography (SIS) and endometrial aspiration can both be performed with the same catheter in 1 session. The objective of this study was to evaluate the effect of the order of investigations (aspiration-SIS vs SIS-aspiration) on the quality of the endometrial sample. Design Single-blind randomized controlled trial (Canadian Task Force classification I). Setting Academic teaching hospital. Patients A total of 113 women with abnormal uterine bleeding who visited the outpatient clinic were included in the study. Interventions The included women were randomly allocated either to SIS and subsequent endometrial aspiration, or to the reverse order. Both examinations were performed in 1 session with the same catheter. All aspiration specimens were sent to the same pathologist, who evaluated the quality of the samples. Measurements and Main Results The quality of the endometrial aspiration specimen was significantly better in the group of women who had aspiration before SIS, compared with women who were allocated to the reverse order (p=.04). Blood and mucus staining and the presence of endometrial epithelium had a significant influence on the sample quality. The difference between both groups was most pronounced in premenopausal women (p=.005). Conclusion This study shows that the proportion of adequate specimens is higher when endometrial aspiration is done first with subsequent SIS. Aspiration should be performed before SIS to decrease the chance of obtaining an insufficient endometrial aspiration specimen.