Table 3.

Results of embryo outcomes between treatment protocol groups obtained using multivariable generalized equation model analyses with adjusted repeated stimulation cycles for a given patient.

Comparison	Achievement of pre-ovulatory follicle			Achievement of MII oocyte			Achievement of top-quality MII oocyte			Achievement of embryo with 2PN
	n1	OR (95% CI)	p-value	n2	OR (95% CI)	p-value	n3	OR (95% CI)	p-value	n3	OR (95% CI)	p-value
Group comparison
Study group versus control group (ref.)	726	1.27 (0.89, 1.82)	0.1803	692	0.90 (0.61, 1.33)	0.6074	345	1.27 (0.79, 2.03)	0.3262	345	1.64 (0.73, 3.69)	0.2316
Protocol A versus protocol B (ref.)	726	1.01 (0.77, 1.32)	0.9624	692	1.00 (0.74, 1.34)	0.9761	345	0.67 (0.44, 1.01)	0.0567	345	0.51 (0.23, 1.10)	0.0855
Subgroup comparison (ref.: study group with protocol B)
Control group with protocol A vs. ref.	509	0.83 (0.57, 1.21)	0.3247	488	1.10 (0.71, 1.70)	0.6804	238	0.65 (0.38, 1.10)	0.1097	238	0.39 (0.13, 1.20)	0.1012
Control group with protocol B vs. ref.	344	0.72 (0.45, 1.18)	0.1912	320	1.28 (0.78, 2.08)	0.3258	154	1.09 (0.62, 1.93)	0.7631	154	0.57 (0.16, 2.04)	0.3890
Study group with protocol A vs. ref.	347	1.09 (0.7, 1.69)	0.7067	316	1.08 (0.69, 1.70)	0.7407	141	0.83 (0.37, 1.85)	0.6433	141	0.43 (0.11, 1.76)	0.2396

MII, metaphase II mature oocyte retrieved; 2PN, two-pronuclear zygote; OR, odds ratio; CI, confidence interval; study group, patients received cotreatment of clomiphene citrate and letrozole in mild ovarian stimulation; control group, patients received conventional ovarian stimulation; protocol A, patients received ovarian stimulation with gonadotropin-releasing hormone GnRH antagonist protocol; protocol B, patients received ovarian stimulation with progestin-primed ovarian stimulation (PPOS) protocol.

•n¹ refers to total number of follicles. n² refers to total number of oocytes. n³ refers to total number of mature embryos.