Defining endometrial growth during the menstrual cycle with three-dimensional ultrasound.
OBJECTIVE
To define the changes in endometrial morphometry that occur during the normal menstrual cycle and to examine the discriminatory power of volumetric analysis over conventional two-dimensional measurements in quantifying the effect of compounding factors on endometrial growth.


METHODS
The design was that of a longitudinal observational study. Subjects were seen on an alternate-day basis until ovulation and then every four days until the next menstrual period.


METHODS
A University teaching hospital.


METHODS
Thirty women with regular cycles and acceptable "normal", menstrual patterns.


METHODS
Three-dimensional ultrasound data were acquired and subsequently analysed by a single observer.


METHODS
Endometrial thickness and volume.


RESULTS
Both endometrial volume and thickness increased significantly during the follicular phase (P < 0.001), reaching a plateau around the time of ovulation and remaining relatively stable throughout the luteal phase. These changes in endometrial thickness and volume were highly correlated (R(2)= 0.767; P < 0.001). Parity was associated with a significantly greater endometrial volume than nulliparity (4.159 vs 2.234 cm(3); P < 0.05).


CONCLUSIONS
This study has defined the relative and absolute changes in endometrial growth, both in terms of thickness and volume, throughout the normal menstrual cycle. These data provide a reference for future three-dimensional studies investigating menstrual disorders, pathophysiological change and subfertility.
School of Human Development, University of Nottingham, Queens Medical Centre, East Block, Nottingham NG7 2UH, UK.
Nicholas J
NJ
Raine-Fenning
Bruce K
BK
Campbell
Jeanette S
JS
Clewes
Nigel R
NR
Kendall
Ian R
IR
Johnson
D000328:Adult; D004717:Endometrium / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008137:Longitudinal Studies; D008597:Menstrual Cycle / Q000502:physiology*; D010060:Ovulation / Q000502:physiology; D010298:Parity; D014463:Ultrasonography