Effect of coincubation time of sperm-oocytes on fertilization, embryonic development, and subsequent pregnancy outcome

Figures & data

Table 1. Comparison of fertilization, embryo quality, pregnancy and implantation rates in the different durations of sperm-oocyte co-incubation with Group I patients.

	Short coincubation (4 hours)	Standard coincubation (16-18 hours)	P Value
No. of patients performed egg retrieval (cycles)	110 (110)	108 (108)	–
Patient age (mean ± SD)	29.0 ± 4.0	29.4 ± 3.8	0.44
Duration of infertility (mean ± SD)	2.4 ± 1.1	2.3 ± 2.0	0.45
No. of mature oocytes retrieved (mean ± SD)	1168 (10.6 ± 6.1)	1139 (10.6 ± 6.1)	0.93
No. of patients failed fertilization (cycles)	0 (0)	1 (1)	–
No. of oocytes fertilized (%)	849 (72.6)	818 (71.8)	0.66
No. of polyspermy oocytes (%)	85 (7.3)	47 (4.1)	0.00
No. of fertilized zygotes cleaved (%)	830 (97.7)	791 (96.7)	0.19
No. of good embryos (%)	553 (66.7)	514 (65.0)	0.49
No. of embryos transferred (mean ± SD)	228 (2.1 ± 0.4)	219 (2.1 ± 0.5)	0.49
No. of cycles performed embryo transfer (%)	110 (100)	107 (99.1)	–
No. of clinical pregnancy (%)	53 (48.2)	49 (45.8)	0.73
No. of embryos implanted (%)	67 (29.4)	63 (28.8)	0.89

Table 2. Comparison of fertilization, embryo quality, pregnancy and implantation rates in the different durations of sperm-oocyte coincubation in Group II patients.

	Short coincubation (4 hours)	Standard coincubation (16-18 hours)	P Value
No. of patients performed egg retrieval (cycles)	110 (110)	103 (103)	–
Patient age (mean ± SD)	29.5 ± 1.9	30.0 ± 1.6	0.06
Duration of infertility (mean ± SD)	2.2 ± 2.6	2.3 ± 2.4	0.49
No. of mature oocytes retrieved (mean ± SD)	813 (7.4 ± 5.2)	743 (7.2 ± 6.3)	0.82
No. of cycles failed fertilization (%)	18 (16.4)	11 (10.7)	0.23
No. of oocytes fertilized (%)	509 (62.60)	511 (68.7)	0.01
No. of polyspermy oocytes (%)	46 (5.7)	33 (4.4)	0.28
No. of fertilized zygotes cleaved (%)	485 (95.2)	490 (95.9)	0.64
No. of good embryos (%)	289 (59.6)	315 (64.2)	0.13
No. of embryos transferred (mean ± SD)	211 (2.3 ± 0.6)	201 (2.2 ± 0.7)	0.26
No. of cycles performed embryo transfer (%)	92 (83.6)	92 (89.3)	0.23
No. of clinical pregnancy (%)	30 (32.6)	31 (33.7)	0.87
No. of embryos implanted (%)	40 (19.0)	39 (19.4)	0.91

Table 3. Pregnancy and implantation outcome in patients from rescue ICSI.

No. of patients performed IVF (cycles)	1,699 (1,738)
No. of patients performed rescue ICSI (%)	77 (4.5)
No. of oocytes performed rescue ICSI (mean ± SD)	683 (8.9 ± 5.5)
No. of oocytes fertilized by rescue ICSI (%)	487 (71.3)
No. of polyspermy oocytes (%)	22 (3.2)
No. of fertilized zygotes cleaved (%)	471 (96.7)
No. of embryos transferred (mean ± SD)	149 (1.9 ± 0.6)
No. of patients performed embryo transfer (%)	75 (97.4)
No. of clinical pregnancy (%)	26 (34.7)
No. of embryos implanted (%)	36 (24.1)
No. of live births (%)	24 (32.0)
No. of miscarriage (%)	3 (11.5)

Table 4. Obstetric and perinatal outcome of the patients who had live births from rescue ICSI.

No. of live births	24
No. of singleton	17
No. of twin	7
No. of triplet	0
Gestational period (week ± days)	37.5 ± 1.1
Birth weight (g, mean ± SD)	3,103 ± 466
Karyotype	15XY; 16XX
Birth defects	0

Figure 1.  Human oocyte with 2 polar bodies extruded into perivitelline space, observed at 4 hours after oocyte-sperm coincubation. Scale bar indicates 40 µm.