Received 16 October 2007; received in revised form 7 January 2008; accepted 7 January 2008. published online 06 March 2008.
Objective
To characterize pathophysiologic features of a “thin” endometrium.
Design
A prospective observational study.
Setting
University Hospital and City General Hospital.
Patient(s)
Patients with normal-thickness endometrium (Normal-Em group: endometrial thickness ≥8 mm; n = 57) and thin endometrium (Thin-Em group: endometrial thickness <8 mm; n = 17).
Main Outcome Measure(s)
Blood flow impedance of the uterine radial artery (RA) was assessed as resistance index (RI) by transvaginal color-pulsed Doppler ultrasonography. The area of glandular epithelium, the number of blood vessels, and vascular endothelial growth factor (VEGF) expression were examined in the midluteal-phase endometrium.
Result(s)
The RA-RI in the Thin-Em group was significantly higher than in the Normal-Em group throughout the menstrual cycle. Endometrial thickness was significantly correlated with RA-RI. Growth of glandular epithelium, the number of blood vessels, and VEGF expression were significantly lower in the Thin-Em group than in the Normal-Em group.
Conclusion(s)
A “thin” endometrium was characterized by high blood flow impedance of RA, poor epithelial growth, decreased VEGF expression, and poor vascular development.
aDepartment of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Ube, Japan
bDepartment of Obstetrics and Gynecology, Saiseikai Shimonoseki General Hospital, Shimonoseki, Japan
Reprint requests: Norihiro Sugino, M.D., Ph.D., Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Minamikogushi 1–1-1, Ube 755–8505, Japan (FAX: +81-836-22-2287).
I.M. has nothing to disclose. H.T. has nothing to disclose. A.T. has nothing to disclose. Y.Y. has nothing to disclose. K.S. nothing to disclose. N.S. has nothing to disclose.
Supported in part by grants-in-aid 17791121, 18791158, and 19791153 for Scientific Research from the Ministry of Education, Science, and Culture, Japan, and registered at clinicaltrials.gov.
ABSTRACT