Table 4.

Neonatal outcomes of FETs stratified by the storage time

	1	2	3	4	5	P1	P2	P3	P4
Birth sex ratio (male/female)	1.24	1.09	1.33	1.35	0.96	< 0.001	< 0.001	< 0.001	< 0.001
male	5856	1458	475	170	171
female	4730	1340	358	126	178
Singleton birth height(cm), mean ± SD	49.01 ± 2.70	49.02 ± 2.58	48.76 ± 2.86	49.39 ± 2.34	49.45 ± 1.91	0.973	0.673	1.082	1.258
Singleton birth weight(kg), mean ± SD	3.03 ± 0.60	2.99 ± 0.61	3.02 ± 0.64	3.04 ± 0.53	3.15 ± 0.38	0.786	0.983	0.819	0.914
Low birth weight (< 2500 g)	19.87(1335/6719)	19.46(380/1953)	18.12(114/629)	15.60(34/218)	15.71(33/210)	0.996	0.351	< 0.001	< 0.001
High birth weight (> 4000 g)	3.66(246/6719)	2.76(54/1953)	3.97(25/629)	1.83(4/218)	3.81(8/210)	< 0.001	0.087	< 0.001	0.068
Congenital anomalies	1.93(130/6719)	1.43(28/1953)	1.91(12/629)	1.83(4/218)	1.91(4/210)	< 0.001	0.293	0.539	0.923

P1: Group 2 vs. Group 1, P2: Group 3 vs. Group 1, P3: Group 4 vs. Group 1, P4: Group 5 vs. Group 1