Table 1.

Summary of data published about the role of 3D-ultrasound for assessing normal menstrual cycle

Author	n	Primary Outcome	3D Method	Study Design	Findings
Lee (45)	18	Uterine-Endometrial volume ratio	Multislice	Longitudinal at 3–6 days interval	Uterine-Endometrial volume ratio decrease throughout menstrual cycle (R2 = 0.4318)
Raine-Fenning (46)	30	Endometrial volume	VOCAL	Longitudinal at 2 days interval in follicular phase and 4 days interval in luteal phase	Endometrial volume increase steadily during follicular phase, plateauing during luteal phase
Raine-Fenning (47)	27	Endometrial and subendometrial vascularity	VOCAL	Longitudinal at 2 days interval in follicular phase and 4 days interval in luteal phase	Endometrial and subendometrial VI/FI/VFI increased from mid-follicular phase peaking 3 days prior to ovulation and then decrease until 5 days postovulation, increasing then again until the next cycle
Jokubkiene (50)	16	Endometrial volume, and endometrial and subendometrial vascularity	VOCAL	Longitudinal, daily in follicular phase and 2 days interval in luteal phase	Endometrial and subendometrial VI/FI/VFI increased from mid-follicular phase peaking 2 days prior to ovulation and then decrease until 2 days after ovulation, increasing then again until the next cycle