Values of n for transvaginal ultrasonography scans, serum hormone measurements, and CPFM results on the respective cycle days relative to ovulation (n = 1 cycle was anovulatory), are given below (Table F1). Prediction of ovulation by urinary hormone measurements with the home use ClearPlan® Fertility Monitor: comparison with transvaginal ultrasound scans and serum hormone measurements Hum Reprod. 2000;15(12):2478-2482. doi:10.1093/humrep/15.12.2478 Hum Reprod | © European Society of Human Reproduction and Embryology