Table 3.

Subgroup analysis of clinical PR according to age, DAF, embryo quality and quantity, ovarian stimulation protocol, and endometrial thickness in cleavage embryos/blastocysts FET cycles.

Variables	Day 3 embryos			Day 5 embryos
	n/total n	%	P	n/total n	%	P
Age, years			0.002			0.000
≤30	58/104	55.7		309/420	73.6
31–37	101/184	54.8		223/369	60.4
>37	6/29	20.6		31/53	58.5
DAF, mm			0.039			0.043
≤3	7/21	33.3		34/54	63.0
3–15	153/280	55.0		485/708	68.5
≥15	5/16	31.3		44/80	55.0
Embryo quality and quantity			0.000			−
SET day 3 (A/B)	16/49	32.7
DET day 3 (B + B)	25/64	39.0
DET day 3 (A + B)	53/99	53.5
DET day 3 (A + A)	71/105	67.6
SET day 5 (B)	−		−	42/87	48.2	0.000
SET day 5 (A)				437/647	67.5
DET day 5 (A/B+ A/B)	−		−	84/108	77.8
Ovarian stimulation protocol			0.152			0.342
GnRH antagonist protocol	78/154	50.6		318/463	68.6
Luteal phase short-acting long protocol	59/104	56.7		173/276	62.6
Follicular phase long-acting long protocol	18/30	60.0		64/92	69.5
Others	10/29	34.5		8/11	72.7
Endometrial thickness, mm			0.010			0.021
<4	3/15	20		26/50	52.0
≥4	162/302	53.6		537/792	67.8

‘A’ presents high-quality embryo; ‘B’ presents non-high-quality embryo.

DAF, distance from the air bubble to endometrial cavity fundus; DET, double embryos transfer; PR, pregnancy rate; SET, single embryo transfer.