Fig. 1

Box plots and Violin plots showing the baseline characteristics, follicle diameter, and hormone levels of all records at three time points before ovulation. The bottom line, middle line, and upper line of the box represents the first quartile, the medium, and the third quartile of the variable. Outliers marked by dots that are either 1.5*IQR or more above the third quartile or 1.5*IQR or more below the first quartile. Violin plots showed the distribution of each variable. 72 h: in 72 h before ovulation; 48 h: in 48 h before ovulation; 24 h: in 24 h before ovulation