Table 1.

Fertilization and blastocyst development rates of embryos derived from oocytes with second polar body extrusion either by spontaneous activation or rescue artificial activation (ROA) and non-ROA that did not exhibit extrusion

	Spontaneously activated oocytes	ROA oocytes	Non-ROA oocytes	P value
				Spontaneously activated oocytes vs. ROA oocytes	ROA oocytes vs. non-ROA oocytes
Number of oocytes	2290	395	75
1PN rate, n (%)	68 (3.0%)	42 (10.6%)	4 (5.3%)	<0.001	0.15
2PN rate, n (%)	2077 (90.7%)	260 (65.8%)	5 (6.7%)	<0.001	<0.001
3PN or higher rate, n (%)	59 (2.6%)	21 (5.3%)	10 (13.3%)	0.0036	0.0093
0PN rate, n (%)	87 (3.8%)	72 (18.2%)	56 (74.7%)	<0.001	<0.001
Blastocyst development rate, n (% per 2PN)	1396 (67.2%)	127 (48.9%)	5 (40.0%)	<0.001	1.00
Good quality blastocyst development rate, n (% per 2PN)	785 (37.8%)	53 (20.5%)	0 (0.0%)	<0.001	0.59