Table IV.

Demographic data showing the timing to development in embryos developing into low- or high-quality blastocysts. Time was counted from thawing of the embryos (n = 30).

	Low-quality blastocysts n = 7		High-quality blastocysts n = 23		P value
	n	median h (range)	n	median h (range)
Time to first cleavage	7	9.3 (3.1–24.6)	23	13.1 (4.3–35.4)	0.477
Time to morula	6	57.2 (45.9–67.3)	23	50.6 (31.3–72.1)a	0.059
Time to start of cavitation	7	69.7 (56.6–79.3)	23	61.1 (42.4–79.4)*	0.039
Time to start of expansion	7	79.0 (60.9–88.1)	23	66.9 (47.9–87.4)	0.091
Time to start of hatching			8	87.2 (70.6–94.1)	N/A

^*P < 0.05 compared with low-quality blastocysts, Mann–Whitney U test.

^aTendency.