Premenopausal bleeding: When should the endometrium be investigated?--A retrospective non-comparative study of 3006 women.

Objective: There is lack of consensus amongst professional organizations as regards the cut-off age for endometrial sampling of premenopausal women presenting with abnormal uterine bleeding (AUB) to exclude endometrial hyperplasia or carcinoma. Therefore we conducted this study to quantify the prevalence of hyperplasia and carcinoma in different age categories in premenopausal women with AUB to identify the appropriate cut-off age for endometrial sampling.

Study Design: A retrospective review of the histopathology reports of endometrial samples taken from 3006 women presenting with AUB and aged from > or =30 to < or =50 years at Ipswich Hospital, UK, from 1 January 1998 to 31 December 2007. Women were divided into three subgroups according to age; group 1: 30 to < or =40 (n=862), group 2: 40 to < or =45 (n=1035) and group 3: 45 to < or =50 (n=1109).

Results: Logistic regression revealed that the prevalence of atypical hyperplasia (OR: 3.85; 95% CI: 1.75, 8.49; p=0.01) and carcinoma (OR: 4.03; 95% CI: 1.54, 10.5; p=0.04) was significantly higher in women in group 3 when compared to younger women. There was no statistically significant difference as regards simple and complex hyperplasia in the different age categories. All but one of the women (n=23) who had complex atypical hyperplasia or carcinoma under the age of 45 years, presented with irregular rather than cyclical heavy menstrual bleeding.

Conclusion: Our study, the largest in the literature, suggests using the age 45 years as a cut-off for sampling the endometrium in all women with AUB. However, irregular menstrual bleeding justifies investigating women regardless of their age.