Sensitivity and specificity of ultrasound indices of ovulation in spontaneous cycles

Self-identification of the clinical fertile window and the ovulation period

“…Scanning was performed every other day until a follicle reached 16 mm and then daily until evidence of ovulation. Details concerning ultrasound investigations were previously published (20). The estimated day of ovulation as determined by ultrasound was defined as the day of maximum follicular enlargement, followed the next day by evidence of rupture.…”

A comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on superovulation in Asian women with normal ovulatory cycles

“…Follicular diameter was determined by calculating the mean of the two perpendicular diameters measured at the largest plane of the follicle. Ovulation was suspected by documenting at least two of the following parameters: (1) a decrease in follicular diameter; (2) blurring of the follicular border; (3) the presence of internal echoes; and (4) free fluid in the cul-de-sac [29]. Ovulation was confirmed by P level 4 ng/ml.…”

Levonorgestrel emergency contraception: a joint analysis of effectiveness and mechanism of action

“…We therefore use a detailed database of follicular measurements. The database was described in detail elsewhere (31,32). In brief, there were 533 ultrasound measurements of follicular size from 327 cycles in 107 women who were not taking hormonal medication and had no history that would suggest subfertility.…”