Artificial oocyte activation using calcium ionophore in ICSI cycles with spermatozoa from different sources

Abstract

The present study evaluated the effect of artificial oocyte activation (AOA) with calcium ionophore A23187 on intracytoplasmic sperm injection (ICSI) cycles using spermatozoa from different sources. The 314 cycles evaluated were divided into three groups according to sperm origin; the ejaculated group (n = 92), the epididymal group (n = 82), and the testicular group (n = 140). Each group was further split into experimental subgroups, depending on whether or not AOA was performed. In addition, the cycles of women younger than 36 years were evaluated separately. For each experimental group, ICSI outcomes were compared between subgroups. No significant difference was observed between subgroups for all sperm origin groups. When evaluating only the cycles of women younger than 36 years of age, AOA increased the percentage of high-quality embryos (74.5 versus 53.0%, P = 0.011) and the implantation rate (19.3 versus 10.5%, P = 0.0025) when it was used with ejaculated spermatozoa, and the percentage of high-quality embryos (64.4 versus 50.3%, P = 0.006) when epididymal spermatozoa were used. These results may suggest that both sperm maturity and oocyte quality play a role in oocyte activation. However, this study is to be continued to confirm these findings.

Phospholipase C-zeta deficiency as a cause for repetitive oocyte fertilization failure during ovarian stimulation for in vitro fertilization with ICSI: a case report

“…Although beyond the scope of this report, Ca 2+ ionophore has been shown to improve embryo development and pregnancy outcome in patients with a history of previous impaired embryo development [17]. Therefore, it is also possible that successful pregnancies after ICSI supplemented with artificial activation of oocytes matured in vitro [33] might be the result of enhanced embryo competence from both improved fertilization and preimplantation embryogenesis [10,15,17].…”

“…As compared to the proven fertile control male (a), the patient's sperm demonstrates decreased quantity and abnormal localization of PLC-ζ in the post-acrosomal region (b). Note that normal location of PLC-ζ is in the equatorial region of the sperm, although some variation can be observed PLC-ζ-deficient sperm [11,14,15,[28][29][30][31][32], our use of Ca 2+ ionophore with in vivo matured PCOS oocytes following ICSI did not overcome the failed fertilization, raising caution with the use of Ca 2+ ionophore and ICSI in this way. Instead, Ca 2+ ionophore was successful in overcoming PLC-ζ-deficient sperm fertilization failure when used after ICSI of PCOS oocytes matured in vitro, supporting a report of successful pregnancy occurring after ICSI with artificial activation of in vitro matured oocytes [33].…”

“…Data regarding Ca 2+ ionophore use with ICSI and its relationship to human oocyte competence, embryo development, and neurodevelopmental outcomes in children appear reassuring [17,37,38], but immature oocytes or mature oocytes failing to fertilize may harbor inherent defects that potentially harm the embryo [39]. Also relevant is the potential impact of Ca 2+ ionophore use with ICSI on the rates of miscarriage, genetic abnormalities, and minor as well as major congenital malformations [15,40]. Theoretically, nonphysiological patterns of calcium oscillation in artificially activated oocytes might perturb calcium-mediated signal transduction, mitochondrial respiration, developmental programming, or epigenetic events in ways that alter postimplantation embryo development [41,42].…”

“…A second GnRH-antagonist ovarian stimulation with IVF/ ICSI was performed using Ca 2+ ionophore with ICSI to enhance Ca 2+ -induced oocyte activation, as previously reported [9,14,15]. This time, rhFSH and urinary gonadotropins were started at a higher dose of 375 IU sc daily for 2 days and then changed as clinically needed.…”

“…Eleven MII oocytes were subjected to ICSI followed by exposure to Ca 2+ ionophore (A23187: 5 μmol/L, Sigma Scientific) in G-1 media (Vitrolife) for 30 min [15]. Oocytes were then washed and placed in the incubator.…”