Table 8 Effect of cytoplasmic fragmentation removal on embryo development

Alikani et al.

1999

Human embryo fragmentation in vitro and its implications for pregnancy and implantation

Retrospective

2,410 patients.

Day-3 embryos.

Mean maternal age 35.7 +/- 4.25 years.

Stimulation with standard down-regulation protocol or a modification of the microflare protocol (Scott and Navot, 1994¹) for pts ≥40 and those with previous response to down-regulation was unsatisfactory.

Degree and pattern of fragmentation on pregnancy and implantation.

Eftekhari-Yazdi et al.

2006

Effect of fragment removal on blastocyst formation and quality of human embryos

Experimental

213 embryos.

4-6 cell surplus human embryos.

Age of female partners:

Control (29.28 +/- 1.58 years), Experimental (28.98 +/- 1.71 years).

Age of male partners: Control (35.22 +/- 3.66 years), Experimental (34.60 +/- 3.97 years)

Ovarian stimulation carried out following down-regulation as previously described by Porter et al., 1984.²

In-vitro development after blastomere fragmentation removal: day-6 size and number of blastomeres.

Keltz et al.

2006

Predictors of embryo fragmentation and outcome after fragment removal in in vitro fertilization

Retrospective

327 nondonor, fresh IVF cycles.

Assisted hatching and fragment removal on Day-3 embryos.

Cycles with fragmented embryos mean age 36.9 +/- 4.24 years.

Cycles with no fragmented embryos mean age 35.4 +/- 4.74 years.

Controlled stimulation during IVF was performed using combination of GnRH agonists and gonadotropins in a long or short protocol for all subjects. Oocytes retrieved 35 hrs after 10,000 IU hCG was administered.

Predictors of fragmentation. Evaluated age, basal FSH and E(2) levels, the number of retrieved oocytes, and fertilization rates. Outcome assessments following defragmentation included rates of implantation, clinical pregnancy, spontaneous abortion, and live birth.

Keltz et al.

2010

Defragmentation of low grade day 3 embryos resulted in sustained reduction in fragmentation, but did not improve compaction or blastulation rates

Prospective

35 paired embryos (treatment and control group); 70 total embryos.

Defragmentation on Day-3 (6-8 cell stage); Fragmentation, compaction, morulation, and blastula formation evaluation on Day-4 or 5.

Controlled stimulation during IVF was performed using combination of GnRH agonists and gonadotropins in a long or short protocol for all subjects. Oocytes retrieved 35 hrs after 10,000 IU hCG was administered.

Day-5 embryo of fragmentation, compaction, morulation, blastulation formation rates.

Halvaei et al.

2016

Ultrastructure of cytoplasmic fragments in human cleavage stage embryos

Prospective

150 ICSI cycles.

Cleavage-stage embryos.

Female age: Control (29.1 +/- 3.7 years),

Sham (31.4 +/- 4.9 years),

Case (29.6 +/- 6 years).

Male age: Control (33.64 +/- 5.3 years),

Sham (35.56 +/- 6.7 years),

Case (35 +/- 6.7 years).

Majority of patients underwent antagonist protocol for ovarian stimulation.

Evaluate ultrastructure of cytoplasmic fragment and perivitelline coarse granulation removal (cosmetic microsurgery) from embryos before embryo transfer on ART outcomes (rates of clinical pregnancy, live

birth, miscarriage, multiple pregnancies, and congenital anomaly).

Yumoto et al.

2020

Removing the zona pellucida can decrease cytoplasmic fragmentations in human embryos: a pilot study using 3PN embryos and time-lapse cinematography

Retrospective

50 patients; 71 zygotes in which 3PN were confirmed after insemination.

ZP-free zygotes were cultured and observed continuously for 5 days in incubator equipped with time-lapse imaging system.

Mean maternal age 36.9 +/- 4.7 years.

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Developmental morphology and embryonic quality.