The validity of transvaginal ultrasound measurement of endometrial thickness: a comparison of ultrasound measurement with direct anatomical measurement.

Objectives: To compare transvaginal ultrasound measurements of endometrial thickness with direct anatomical measurements and consider the implications of these findings on clinical practice.

Design: Prospective observational study using two modalities blinded to each other's findings.

Setting: Singleton Hospital, Swansea, a medium-sized District General Hospital.