中空透明帶(ZP)以雷射打薄後再施行精蟲顯微注射(ICSI)可能可提高胚胎之品質
http://humrep.oxfordjournals.org/content/19/3/573.full
Laser‐assisted zona pellucida thinning prior to routine ICSI
- M. Moser1,
- T. Ebner,
- M. Sommergruber,
- U. Gaisswinkler,
- K. Jesacher,
- M. Puchner,
- R. Wiesinger and
- G. Tews
+Author Affiliations
- 1To whom correspondence should be addressed. e‐mail: Marianne.moser@gespag.at
- Received August 22, 2003.
- Revision received October 16, 2003.
- Accepted October 22, 2003.
Abstract
BACKGROUND: In MII oocytes showing difficult oolemma breakage, ICSI can cause an increase in the degeneration rate. This may be overcome by laser‐assisted ICSI using a 5–10 µm opening in the zona pellucida for injection. However, such a small opening might impair the hatching process, especially if assisted hatching is applied in addition. In order to prevent this, the present study used routine injection through an area of zona pellucida in which laser zona thinning had been applied, providing for both a reduced mechanical stress to the oocyte and assisted hatching. METHODS: This prospective study involved 100 cycles with 1016 MII oocytes. Conventional ICSI (control group) was compared with a modified laser‐assisted ICSI (study group) in sibling oocytes. In the latter group oocytes were injected through an extended area of zona thinning. RESULTS: Degeneration rate was significantly lower in the study group (P < 0.004). There were no differences in fertilization, or formation and quality of blastocysts. In the study group embryo quality on day 2 was significantly better (P = 0.004) and herniation of day 5 blastocysts was increased (P = 0.005). Rates of implantation and pregnancy were not affected. However, on day 3 laser‐assisted ICSI proved beneficial (P = 0.038) in terms of clinical pregnancy rate. CONCLUSIONS: The new method combines a less invasive ICSI technique with assisted hatching. Our preliminary data indicate that in addition to an improved oocyte survival, this new approach increases the hatching rate in vitro, which may explain the increase in pregnancy rate, at least in day 3 transfers.
Figure 1. Zona thinning by successively
applying five to six laser shots using a
non‐contact 1.48 µm wavelength diode laser
prior to ICSI.
Table I.
Comparison of preimplantation development in vitro between laser‐assisted ICSI and conventional ICSI
| Laser‐assisted ICSI | Conventional ICSI | |
| Number of MII oocytes | 514 | 502 |
| Fertilization (2PN) | 350 (68.1) | 332 (66.1) |
| No fertilization | 114 (22.2) | 98 (19.5) |
| 1 PN | 6 (1.2) | 3 (0.6) |
| 3 PN | 13 (2.5) | 13 (2.6) |
| Degeneration | 31 (6.0)a | 56 (11.2)a |
| No or minor fragmentation on day 2 | 237/360 (65.8)a | 192/348 (55.2)a |
| No or minor fragmentation on day 3 | 206/360 (57.2) | 178/348 (51.2) |
| Day 4 compaction | 142/235 (60.4) | 120/229 (52.4) |
| Day 5 number of blastocysts | 111/235 (47.2) | 102/229 (44.5) |
| Good quality blastocysts | 34/81 (42.0) | 33/82 (40.2) |
| Hatching blastocysts | 27/111 (24.3)b | 10/102 (9.8)b |
Numbers in parentheses are percentages. Embryos with minor fragmentation show <10% fragments. Blastocyst quality was evaluated in cases of a clearly distinguishable inner cell mass.
aP = 0.004; bP = 0.005.
Table III.
Implantation behavior and clinical pregnancy rate in homogeneous and mixed embryo and blastocyst transfers
| Transfer | Study group only | Mixed | Control group only |
| Total | |||
| N | 33 | 46 | 21 |
| Clinical pregnancies | 14 (42.4) | 19 (41.3) | 5 (23.8) |
| Implantation rate | 19/62 (30.7) | 20/92 (21.7) | 9/46 (19.6) |
| Day 3 | |||
| N | 19 | 18 | 12 |
| Clinical pregnancies | 9 (47.4)a | 6 (33.3)a | 1 (8.3)a |
| Implantation rate | 9/33 (27.3) | 7/40 (17.5) | 2/22 (9.1) |
| Day 5 | |||
| N | 14 | 28 | 9 |
| Clinical pregnancies | 5 (35.7) | 13 (46.4) | 4 (44.4) |
| Implantation rate | 10/29 (34.5) | 13/52 (25.0) | 7/24 (29.2) |
Values in parentheses are percentages.
aP = 0.039 (study group and mixed group compared with control group).
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