Table 3.

Comparison of the cycle characteristics of the CC + letrozole and CC-alone groups

Characteristic	Letrozole + CC group (n = 48)	Clomiphene citrate group (n = 47)	P-values
Progestin withdrawal, n (%)	13 (35.4)	14 (29.8)	0.714
Ultrasound cycle day, median (min, max)	13 (11, 15)	13 (12, 16)	0.940
Reported urine LH surge, n (%)	29 (60.4)	34 (72)	0.311
Cycle day of LH surge  median (min, max)	(n = 29) 16 (12, 21)	(n = 34) 15 (12, 18)	0.191
No. of follicles > 10 mm, median (min, max)	1 (0, 5)	1 (0, 5)	0.815
No. of follicles > 14 mm, median (min, max)	1 (0, 5)	1 (0, 5)	0.919
No. of women with follicle > 14 mm, n (%)	31 (64.6)	30 (63.8)	1.000
Largest follicle size (mm), median (min, max)	16.75 (0, 35)	15.50 (5.5, 35.5)	0.687
Endometrial lining thickness (mm), median (min, max)	6.85 (3.1, 13.5)	7.40 (3.6, 12.6)	0.171
Cycle day progesterone level obtained, median (min, max)	22 (19, 28)	22 (19, 28)	0.768
Progesterone level, ng/ml, median (min, max)	18.40 (0.05, 60)	17.90 (0.05, 60)	0.387
Cycle characteristics of those who ovulated	Letrozole + CC group (n = 37)	Clomiphene citrate group (n = 33)
Progestin withdrawal, n (%)	10 (27)	9 (27.3)	1.000
Ultrasound cycle day, median (min, max)	13 (11, 15)	13 (12, 15)	0.197
Reported urine LH surge, n (%)	28 (75.7)	28 (84.8)	0.510
Cycle day of LH surge, median (min, max)	16 (12, 21)	15 (12, 18)	0.379
No. of follicles > 10 mm, median (min, max)	2 (0, 5)	2 (0, 5)	0.922
No. of follicles > 14 mm, median (min, max)	1 (0, 5)	1 (0, 5)	0.712
No. of women with follicles > 14 mm, n (%)	29 (78.4)	27 (81.8)	0.952
Largest follicle size, mm, median (min, max)	17.6 (0, 35)	20.5 (9.5, 35.5)	0.572
Endometrial lining thickness, mm, median (min, max)	7 (3.5, 13.5)	8 (3.6, 12.6)	0.441
Cycle day progesterone level obtained, median (min, max)	22 (19, 28)	22 (19, 28)	0.990
Progesterone level, ng/ml, median (min, max)	27.80 (3.5, 60)	25.10 (3.28, 60)	0.860