Figure 3. Peak instantaneous frequencies during each phase of stimulation. (A) Primary endings (n = 43). (B) Secondary endings (n = 27). Significantly lower instantaneous frequencies were observed after 5 and 10 days of iOVD in secondary and primary endings, respectively, except for phase 3 in primary endings. Data points represent data averaged from 5 consecutive cycles in each unit. Error bars indicate SD. *Statistical significance vs. control; ANOVA followed by Scheffé’s post hoc test (5% significance level).