Artificial Oocyte Activation Research Articles

Current Topics in Assisted Reproduction in the Czech Republic

Abstract Assisted reproduction is a very dynamic part of reproductive gynaecology with fast changes in therapeutic approaches resulting from intensive research supported by private or public companies. This progress brings also new questions regarding ethical, legal or therapeutic issues. At the 26th Czech-Slovak symposium of assisted reproduction in Brno, several interesting topics of assisted reproduction were presented. During two days, more than 350 specialists discussed current topics related to gynaecology, embryology, andrology, genetics and sexology. From this fruitful discussion we chose the following topics that we consider to be the most important: (1) “Soft” versus “standard” stimulation protocols for IVF (2) Use of exogenous and endogenous progestins in IVF stimulation protocols (3) Cryopreservation and transplantation of ovarian tissue - state of the art and situation in the Czech Republic (4) Selection of spermatozoa with fragmented DNA: practical recommendations (5) Artificial activation of oocytes (8) Access of single and lesbian women to assisted reproduction technologies and possibility of their reproduction in the Czech Republic. Panel conclusions were presented at the end of the conference, which had great attendance, invoked lively commentaries and produced some definitive consensus. Certain issues remained inconclusive and these matters will be the subject of further discussion in future. This is a summary of the most important theses from this field in the Czech Republic in 2017.

Improvement in reproductive outcome through artificial oocyte activation on fertilization failure cases: a cohort study

Improvement in reproductive outcome through artificial oocyte activation on fertilization failure cases: a cohort study

A novel artificial oocyte activation method: using nanosecond pulsed electric fields (nsPEFs) to regulate calcium oscillation patterns

A novel artificial oocyte activation method: using nanosecond pulsed electric fields (nsPEFs) to regulate calcium oscillation patterns

Artificial oocyte activation with SrCl2 or calcimycin after ICSI improves clinical and embryological outcomes compared with ICSI alone: results of a randomized clinical trial.

Are pregnancy and birth rates affected by artificial oocyte activation (AOA) with SrCl2 or calcimycin after ICSI for couples with male-factor infertility linked to abnormal sperm morphology or for couples with previous ICSI cycles of unexplained low fertilization or inadequate fertilization associated with impaired oocyte morphology? AOA with either SrCl2 or calcimycin can improve the rates of clinical pregnancy, ongoing pregnancy and live birth compared with ICSI alone, and the two agents have diverse effects for different subgroups of patients. ICSI is a successful treatment for infertility, but not in all individuals. AOA has potential to overcome inadequate fertilization in ICSI. Calcimycin and SrCl2 are candidate agents for AOA, but their effectiveness remains to be compared. This study was a randomized, open-label, three-arm, parallel-group, double-centre, superiority trial conducted between April 2015 and January 2016. The study evaluated the effects of AOA with calcimycin or SrCl2 for clinical pregnancy rates after ICSI and included 343 couples divided into three groups. Couples were included if they had two previous ICSI cycles of no or low fertilization (0-30%) with unknown causes or impaired oocyte morphology. Male-factor infertility cycles (frozen-thawed sperm, surgically retrieved sperm or ejaculates contained <10 millions spermatozoa/ml) undergoing their first ICSI attempt were also included if they had 100% abnormal sperm morphology (including globozoospermia and tapered-head). Couples were randomized to undergo ICSI with SrCl2 AOA, ICSI with calcimycin AOA or ICSI alone, with clinical pregnancy as the primary endpoint. Effect sizes were summarized as absolute rate differences (ARDs) and odds ratios (ORs), with precision evaluated by 95% CIs. Both SrCl2 and calcimycin AOA improved clinical pregnancy rates compared to ICSI alone (49, 42 and 27%; ARD 22, 95% CI: 9-33; P = 0.0007 and ARD 16, 95% CI: 3-27; P = 0.014). SrCl2 and calcimycin AOA were also superior to ICSI alone on the rates of ongoing pregnancy (42, 36 and 23%; P = 0.0019 and P = 0.023) and live birth (40, 33 and 18%; P = 0.0002 and P = 0.012). Among couples with previous ICSI cycles of low fertilization, AOA with SrCl2 (but not with calcimycin) was superior to ICSI alone for rates of clinical pregnancy (ARD 35 percentage points (pp), P = 0.0007), ongoing pregnancy (ARD 27 pp, P = 0.009) and live birth (ARD 37 pp, P = 0.002). Among couples affected by male-factor infertility, AOA with calcimycin (but not with SrCl2) was superior to ICSI alone for rates of clinical pregnancy (ARD 22 pp, P = 0.006), ongoing pregnancy (ARD 19 pp, P = 0.013) and live birth (ARD 17 pp, P = 0.02). This study was an open-label trial, and this design might have introduced bias, although randomization methods were used. The study did not include a longitudinal follow-up, so further evidence is required to demonstrate the safety of AOA. The decision to use SrCl2 or calcimycin for AOA after ICSI may depend on whether the activation failure originates in the oocyte or the sperm. The study received no funding and the authors have no conflicts of interest to declare. NCT02424214. 22 April 2015. 27 April 2015.

Ionophore treatment for artificial oocyte activation does not alter morphokinetics of the associated embryos

Introduction: In order to rescue cycles with known fertilization problems ionophores are used to artificially activate oocytes, to achieve fertilizations, and eventually to guarantee embryo transfer. Since the calcium signal created is not in its physiological oscillating form there are concerns about its safety.

Artificial oocyte activation with calcium ionophore for frozen sperm cycles

ABSTRACTFertilization problems are the major problems that may be faced in 30–55% of the patients during an intracytoplasmic sperm injection (ICSI) cycle. A successful oocyte activation depends on factors related to both sperm and oocyte, and one of the important factors that mediates the process is Ca2+ concentration within the oocyte. Artificial oocyte activation (AOA) is a method used for fertilization problems that commonly involve the usage of Ca2+ ionophores and is usually used in problems such as total fertilization failure (TFF) and globozoospermia. The aim of the present study was to investigate possible effects of AOA for different groups of patients with fertilization failure. Four groups of patients (previous TFF, low oocyte number, severe sperm quality, and frozen sperm (FS) group) that underwent ICSI with AOA were included in the study. All groups had similar control groups with same indications except TFF, where AOA was not performed. Fertilization rates were significantly higher in the TFF group than those observed in other AOA groups. Fertilization rates and quality of embryos observed in the remaining AOA groups were higher than those of the controls, which were statistically insignificant. Prgenancy rates were higher in all AOA groups compared to the controls, although the differences were significant in FS group only. Quality of embryos and pregnancy rates were lower in the TFF group compared to the remaining AOA groups indicating possible concomitant problems. Fertilization rates, quality of embryos and pregnancy rates seemed to be increased in all indication groups suggesting that not only TFF patients but also a wide variety of patients with different indications may benefit from AOA.Abbreviations: ICSI: Intracytoplasmic sperm injection; ARTs: Assisted reproductive techniques; Ca: Calcium; AOA: Artificial oocyte activation; TFF: Total fertilization failures; OAT: Oligoasthenoteratozoospemia; IVF: In vitro fertilization; SOAT: Severe OAT; LON: Low ooctye number; FS: Frozen sperm; hCG: human chorionic gonadotrophin; PVP: polyvinylpyrrolidone; HSA: human serum albumin

Oocyte-activating capacity of fresh and frozen-thawed spermatids in the common marmoset (Callithrix jacchus).

The common marmoset (Callithrix jacchus) represents a promising nonhuman primate model for the study of human diseases because of its small size, ease of handling, and availability of gene-modified animals. Here, we aimed to devise reproductive technology for marmoset spermatid injection using immature males for a possible rapid generational turnover. Spermatids at each step could be identified easily by their morphology under differential interference microscopy: thus, early round spermatids had a round nucleus with a few nucleolus-like structures and abundant cytoplasm, as in other mammals. The spermatids acquired oocyte-activating capacity at the late round spermatid stage, as confirmed by the resumption of meiosis and Ca2+ oscillations upon injection into mouse oocytes. The spermatids could be cryopreserved efficiently with a simple medium containing glycerol and CELL BANKER®. Late round or elongated spermatids first appeared at 10-12 months of age, 6-8 months before sexual maturation. Marmoset oocytes microinjected with frozen-thawed late round or elongated spermatids retrieved from a 12-month-old male marmoset developed to the 8-cell stage without the need for artificial oocyte activation stimulation. Thus, it might be possible to shorten the intergeneration time by spermatid injection, from 2 years (by natural mating) to 13-15 months including gestation.

Patients undergoing preimplantation genetic screening may benefit from artificial oocyte activation

Patients undergoing preimplantation genetic screening may benefit from artificial oocyte activation

Developmental competence of cat (Felis domesticus) oocytes and embryos after parthenogenetic stimulation using different methods.

The aim of this study was to compare the effects of various activating factors on feline oocytes. The study included activation within the ovary (natural), activation during in vitro maturation (spontaneous activation), chemical activation (ionomycin + 6-DMAP), activation by spermatozoa and injection (ICSI) and mechanical activation (sham ICSI). According to our results, parthenogenetic embryos could emerge at every step of in vitro embryo production (IVP) procedures. After oocyte collection, 6% of parthenogenetic embryos were observed, mainly at the 2-4-blastomere stages. After 24 h of in vitro maturation, parthenogenetic activation was observed in 7% of oocytes. Using ionomycin and 6-DMAP to artificially activate oocytes, 53% of cleaved embryos were obtained. The results after ICSI (54% cleaved embryos) were not significantly different from the results in Group III using chemical activation (53% cleaved embryos). But only after ICSI were blastocysts obtained (5/73.7%) as a result of in vitro culture. Moreover, embryos after ICSI were of the best morphological quality with minor levels of fragmentation evident in the embryos. After sham mechanical activation, 'sham ICSI', 8% of cleaved embryos were noted. Therefore, it is advised to maintain a negative control in parallel with each step of IVP techniques, to avoid misleading results. Chemical methods for artificial activation of feline oocytes are the most promising for application to the cloning and production of parthenogenetic embryos for experimental studies.

Dehydroepiandrosterone (DHEA) and Its Sulfate (DHEA-S) in Mammalian Reproduction: Known Roles and Novel Paradigms.

Steroid hormones form an integral part of normal development in mammalian organisms. Cholesterol is the parent compound from which all steroid hormones are synthesized. The product pregnenolone formed from cholesterol serves as precursor for mineralocorticoids, glucocorticoids, as well as dehydroepiandrosterone (DHEA) and its derived sexual hormones. DHEA assumes the prohormone status of a predominant endogenous precursor and a metabolic intermediate in ovarian follicular steroidogenesis. DHEA supplementation has been used to enhance ovarian reserve. Steroids like estradiol and testosterone have long been contemplated to play important roles in regulating meiotic maturation of oocytes in conjunction with gonadotropins. It is known that oocyte priming with estrogen is necessary to develop calcium (Ca2+) oscillations during maturation. Accruing evidence from diverse studies suggests that DHEA and its sulfate (dehydroepiandrosterone sulfate, DHEA-S) play significantly vital role not only as intermediates in androgen and estrogen formation, but may also be the probable 'oocyte factor' and behave as endogenous agonists triggering calcium oscillations for oocyte activation. DHEA/DHEA-S have been reported to regulate calcium channels for the passage of Ca2+ through the oocyte cytoplasm and for maintaining required threshold of Ca2+ oscillations. This role of DHEA/DHEA-S assumes critical significance in assisted reproductive technology and in-vitro fertilization treatment cycles where physical, chemical, and mechanical methods are employed for artificial oocyte activation to enhance fertilization rates. However, since these methods are invasive and may also cause adverse epigenetic modifications; oral or culture-media supplementation with DHEA/DHEA-S provides a noninvasive innate mechanism of in-vitro oocyte activation based on physiological metabolic pathway.

Expression of sperm PLCζ and clinical outcomes of ICSI-AOA in men affected by globozoospermia due to DPY19L2 deletion.

Globozoospermia is characterized by the presence of 100% acrosomeless round-headed spermatozoa in an ejaculate. Failed fertilization after intracytoplasmic sperm injection (ICSI) is commonly reported for globozoospermic couples and can be overcome by artificial oocyte activation (AOA). Phospholipase C zeta (PLCζ) is one of the main sperm factors involved in oocyte activation and its low expression levels mainly account for fertilization failure. Deletion of the DPY19L2 gene is reported as a main genetic cause in over 70% of infertile men with globozoospermia. The current study assesses the expression profile of sperm PLCζ at RNA and protein levels in 32 DPY19L2 deletion-mediated globozoospermic men and reports corresponding clinical outcomes following ICSI with AOA. The expression of PLCζ relative to GAPDH at RNA (0.78 ± 0.16 versus 1.65 ± 0.24; P = 0.02) and protein (0.39 ± 0.12 versus 0.83 ± 0.13; P = 0.01) levels in globozoospermic men with DPY19L2 deletion was significantly lower compared with fertile men (n = 32). Fertilization rate in globozoospermic couples following ICSI-AOA was significantly lower compared with fertile men (53.14 ± 5.13% versus 87.64 ± 2.38%, P < 0.001). However, implantation (26.2%) and pregnancy (53.8%) rates were not jeopardized by DPY19L2 deletion in these couples.

152 Activation of Bovine Oocytes Using the Zinc Chelator TPEN

Traditionally, artificial oocyte activation has been induced by stimulating intracellular calcium increase in the oocyte. Recently, the use of zinc chelators has also shown to be effective in inducing activation by decreasing intracellular concentration of zinc, mimicking events during fertilization; however, this has not been demonstrated in bovine oocytes. The use of artificial activation in bovine has potential for overcoming subfertility-related production loss and aid in livestock cloning. In this study, we determined whether bovine oocytes could be artificially activated in the presence of the zinc chelator TPEN [N,N,N’,N’-tetrakis(2-pyridylmethyl) ethane-1,2-diamine]. Bovine cumulus–oocyte complexes (COC) were collected from abattoir-derived ovaries and incubated for 24 h in TCM-199 maturation medium supplemented with fetal bovine serum, sodium pyruvate, Glutamax, oestradiol, and FSH. The COC were denuded by vortexing in denuding medium containing 0.1% hyaluronidase, and individual oocytes were selected based on presence of a visible polar body. Matured oocytes were then incubated in TL-HEPES medium supplemented with 1 of 5 treatments for parthenogenetic activation: (1) DMSO for 2 h (control, n = 116), (2) 100 µM TPEN for 45 min (100-45, n = 103), (3) 100 µM TPEN for 120 min (100-120, n = 102), (4) 200 µM TPEN for 45 min (200-45, n = 63), or (5) 200 µM TPEN for 120 min (200-120, n = 142). After treatment, oocytes were washed with culture media and incubated in droplets of SOF-Be1 medium under oil to monitor subsequent development. The number of blastocysts was recorded on Day 10 of culture. Blastocysts were stained with Hoechst for 15 min to evaluate total cell number. The frequencies of blastocyst formation were compared using the Chi-squared test, and differences in total cell number were compared using the Student’s t-test. All TPEN treatments significantly increased the number of oocytes developed to the blastocyst stage relative to the control group, which was unable to form blastocysts (P &lt; 0.01). The 100-45 treatment had a greater % blastocysts compared with the 200-120 treatment (16.5% vs 7.77%; P &lt; 0.05), tended to be greater than 100-120 treatment (16.5% vs 7.8%, P = 0.058), and was numerically greater than the 200-45 treatment (16.5% vs 7.94%; P = 0.114). Three treatments that resulted in blastocysts were analyzed for cell counting: 200-120 (n = 5), 100-120 (n = 4), and 100-45 (n = 7). Average total cell number was 119.20 ± 52.28 for the 200-120 group, 83.75 ± 51.06 for the 100-120 group, and 111.71 ± 59.06 for the 100-45 group. There was no difference in total cell number among groups (P ≥ 0.341). Here, we demonstrated that mature bovine oocytes can successfully be parthenogenetically activated by incubating with the zinc chelator TPEN. Oocytes incubated with 100 µM TPEN for 45 min provided the greatest blastocyst yield. Total cell number did not differ between treatments, but all groups analyzed showed blastocysts containing over 100 cells, demonstrating the effectiveness of the oocyte activation approach. Further studies will focus on optimizing the use of TPEN to activate bovine oocytes.

Sperm-derived factors enhance the in vitro developmental potential of haploid parthenotes.

Parthenotes are characterized by poor in vitro developmental potential either due to the ploidy status or the absence of paternal factors. In the present study, we demonstrate the beneficial role of sperm-derived factors (SDF) on the in vitro development of mouse parthenotes. Mature (MII) oocytes collected from superovulated Swiss albino mice were activated using strontium chloride (SrCl2) in the presence or absence of various concentrations of SDF in M16 medium. The presence of SDF in activation medium did not have any significant influence on the activation rate. However, a significant increase in the developmental potential of the embryos and increased blastocyst rate (P < 0.01) was observed at 50 µg/ml concentration. Furthermore, the activated oocytes from this group exhibited early cleavage and cortical distribution of cortical granules that was similar to that of normally fertilized zygotes. Culturing 2-cell stage parthenotes in the presence of SDF significantly improved the developmental potential (P < 0.05) indicating that they also play a significant role in embryo development. In conclusion, artificial activation of oocytes with SDF can improve the developmental potential of parthenotes in vitro.

Artificial oocyte activation improves later embryonic development in patients with a history of impaired fertilization

Artificial oocyte activation (AOA) has been a therapeutic option for patients with a history of fertilization failure. In mammalian oocytes, optimal activation is related to proper embryonic cleavage. However, little is known about the effect of AOA on the development of human embryos. In addition, whether sperm origin has any impact on the development of AOA embryos is not well understood. In order to examine the effect of AOA on late embryonic development, ICSI outcome was compared between non-AOA and AOA cycles in patients with various fertilization rates and different sperm origin, ejaculated (EJ) and TESE sperm. Retrospective comparative analysis. Consenting patients were grouped according to the sperm origin as well as fertilization rates in initial non-AOA cycles. For AOA, ICSI inseminated oocytes were exposed to 10 μM A23187 calcium ionophore for 15 minutes. Developed embryos were vitrified, and warmed-replaced in subsequent embryo transfer cycles. The rates of fertilization (FR), blastulation (BR), good quality blastocyst (GQB), clinical pregnancy (PR), and on-going pregnancy (OGP) were compared between non-AOA and AOA cycles. Total of 108 with EJ and 33 patients with TESE sperm underwent 196 and 42 initial non-AOA cycles followed by 234 and 66 AOA cycles, respectively. Each group was further divided into three subgroups according to initial non-AOA fertilization rates, i.e., low (<30%), sub-optimal (30-60%), and satisfactory (>60%). With both EJ and TESE sperm, the FR after AOA was significantly improved from non-AOA cycles in all (P < 0.01), but satisfactory group as expected. Interestingly, AOA treatment remarkably increased BR and GQB in sub-optimal group with EJ sperm (32.8 vs 68.5 and 6.3 vs 32.7%, P < 0.01), while no AOA effect on embryonic development was observed with TESE sperm. Importantly, overall PR and OGP after AOA were obviously improved regardless of sperm origin (4.8 vs 21.3 and 1.6 vs 17.4% with EJ, 14.8 vs 58.1 and 3.7 vs 37.2% with TESE, P < 0.01). AOA was effective in improving fertilization and blastocyst formation rates in patients with a history of impaired fertilization, consequently increased embryos available for transfer and successful pregnancies. Although AOA had no effect in patients with satisfactory fertilization rate, those with sub-optimal fertilization may benefit from AOA by improving also the late embryonic development. Finally, the sperm origin influenced the effect of AOA on embryonic cleavage.

Does the use of calcium ionophore during artificial oocyte activation demonstrate an effect on pregnancy rate? A meta-analysis

To study the effect, if any, of calcium ionophore as a method of artificial oocyte activation (AOA) on pregnancy outcomes and fertilization rates. Meta-analysis of randomized controlled trials, prospective observational and retrospective trials, case reports, and a case-control trial. University-affiliated teaching hospital. Infertile couples undergoing fertilization treatment. Use of calcium ionophore during AOA. Odds ratio (OR) as the summary statistic for binary variables was used. Both a fixed and random effects model were applied. Subgroup analysis using quantitative methodology (risk of bias, metaregression) and graphical comparison (funnel plot) assessed statistical heterogeneity. Fourteen studies were selected. AOA with calcium ionophore increased the overall clinical pregnancy rate (per ET; OR = 3.48; 95% confidence interval [CI], 1.65-7.37) and the live birth rate (OR = 3.33; 95% CI, 1.50-7.39). This effect of adding calcium ionophore was further demonstrated with fertilization, cleavage, blastocyst, and implantation rates. Subgroup analysis further supported our findings (studies where n > 10 in both arms; random and fixed effects models). A metaregression (beta = -.145) found that as the quality of the study increases, the effect of calcium ionophore is significantly more pronounced with regards to overall pregnancy rate. AOA with calcium ionophore treatment after intracytoplasmic sperm injection (ICSI) results in a statistically significant improvement in fertilization, cleavage, blastulation, and implantation rates, as well as overall pregnancy and live-birth rates. The conclusion of this systematic review, demonstrating a strong effect of calcium ionophore use, is reassuring and promising, particularly for couples for whom ICSI alone yields poor fertilization rates.

Relationship between phospholipase C-zeta, semen parameters, and chromatin status

ABSTRACTThe need for additional tests to complement basic sperm analysis in clinics is well appreciated. In this regard, a number of tests such as sperm DNA integrity test as a tool in diagnosis and treatment of infertility are suggested. But recent studies have focused on main sperm factors involved in oocyte activation such as phospholipase C-zeta (PLCζ) that initiate intracellular Ca2+ signaling and embryogenesis. Therefore, this study aimed to investigate the relationship between PLCζ, basic semen parameters, sperm DNA fragmentation (SDF), and protamine deficiency in men with normal (n=32) and abnormal (n=23) semen parameters. Unlike SDF and protamine deficiency, as negative factors related to fertility, the mean value of PLCζ as positive factor related to infertility was significantly lower in men with abnormal semen parameters compared to men with normal semen parameters. Significant correlations were also observed between sperm concentration, motility, and abnormal morphology with the percentage of PLCζ positive spermatozoa. In addition, logistic regression analysis revealed that sperm morphology is more predictive than sperm motility and concentration for PLCζ presence. In addition, a statistically significant negative relationship was observed between the percentage of PLCζ positive spermatozoa and SDF. These findings suggested during ICSI, selection of sperm based on morphology has a profound effect on its ability to induce oocyte activation based on the likelihood of PLCζ expression. Therefore, assessment of PLCζ as an index for fertilization potential of a semen sample in men with severe teratozoospermia may define individuals who are candidates for artificial oocyte activation (AOA) and may avoid failed fertilization post ICSI.

Effects of trehalose vitrification and artificial oocyte activation on the development competence of human immature oocytes

Sucrose and trehalose are conventional cryoprotectant additives for oocytes and embryos. Ethanol can artificially enhance activation of inseminated mature oocytes. This study aims to investigate whether artificial oocyte activation (AOA) with ethanol can promote the development competence of in vitro matured oocytes. A total of 810 human immature oocytes, obtained from 325 patients undergoing normal stimulated oocyte retrieval cycles, were in vitro maturated (IVM) either immediately after collection (Fresh group n = 291)) or after being vitrified as immature oocytes (Vitrified group n = 519). These groups were arbitrarily assigned. All fresh and vitrified oocytes which matured after a period of IVM then underwent intra-cytoplasmic sperm injection (ICSI). Half an hour following ICSI, they were either activated by 7% ethanol (AOA group) or left untreated (Non-AOA group). Fertilization, cleavage rate, blastocyst quality and aneuploidy rate were then evaluated. High-quality blastocysts were only obtained in both the fresh and vitrified groups which had undergone AOA after ICSI. Trehalose vitrification slightly, but not significantly, increased the formation rates of high-quality embryos (21.7% VS 15.4%, P > 0.05) and blastocysts (15.7% VS 7.69%, P > 0.05)) when compared with sucrose vitrification. Aneuploidy was observed in 12 of 24 (50%) of the AOA derived high quality blastocysts. High-quality blastocysts only developed from fresh or vitrified immature oocytes if the ICSI was followed by AOA. This information may be important for human immature oocytes commonly retrieved in normal stimulation cycles and may be particularly important for certain patient groups, such as cancer patients. AOA with an appropriate concentration of ethanol can enhance the developmental competence of embryos.

A control study of artificial oocyte activation in the same period

Objective: To compare the fertility rate and embryo outcome between normal fertilization and the use of Calcium ionophore A23187 on the same period of the same cycle of human ovum for artificial activation. Methods: Patients who conducted the intracytoplasmic sperm injection (ICSI) cycle in vitro fertilization assisted reproductive from January 2015 to December in reproductive center of the Third Affiliated Hospital of Zhengzhou University were enrolled.The protocol of this study was approved by the ethics committee of The Third Affiliated Hospital of Zhengzhou University.The subjects must met at least one of the inclusion criteria: (1)the normal fertilization rate was less than 30% ICSI in the previous ICSI cycle; (2)no good quality embryos in a previous period of third days in ICSI; (3)patients with globozoospermia.The ovum were randomly divided into two groups, control group and artificial oocyte activation (AOA) group. In the control group, the eggs were treated with routine ICSI operation, and the AOA group was activated by A23187 after ICSI. Normal fertilization rate, cleavage rate, pregnancy and birth outcome of two groups were compared. Results: The 2PN fertilization rate in the AOA group 65.93% (60/91) was significantly higher than that in the control group 46.67% (41/89) (P<0.05). In addition, in patients who met the inclusion criteria of 1 categories (2PN≤30%), the 2PN fertilization rate was significantly higher (P<0.05) in the AOA group [79.59% (39/49)] compared with the control group [57.14% (28/49)]. In patients who met the inclusion criteria of 3 categories (globozoospermia), the 2PN fertilization rate was significantly higher (P<0.05) in the AOA group [75% (6/8)] compared with the control group [0% (0/5)]. Conclusions: The use of calcium ionophore A23187 assisted activation could be helpful to improve the normal fertilization rate of ICSI. But the effects of early embryonic development and the safety of generation need to be further studied.

The combination of calcium ionophore A23187 and GM-CSF can safely salvage aged human unfertilized oocytes after ICSI.

Artificial oocyte activation using calcium ionophores and enhancement of embryonic developmental potential by the granulocyte-macrophage colony-stimulating factor (GM-CSF) have already been reported. In this study, we evaluated the synergistic effect of these two methods on aged human unfertilized oocytes after intracytoplasmic sperm injection (ICSI). Then, we cultured the resulting embryos to the blastocyst stage and screened them for chromosomal abnormalities, to assess the safety of this protocol. Aged human oocytes deemed unfertilized after ICSI were activated, either by briefly applying the calcium ionophore A23187 alone (group A) or by briefly applying the ionophore and then supplementing the culture medium with recombinant human GM-CSF (rhGM-CSF) (group B). Next, the development was monitored in a time-lapse incubator system, and ploidy was analyzed by array comparative genomic hybridization (aCGH), after whole embryo biopsy and whole genome amplification. Differences between oocytes and resulting embryos in both groups were evaluated statistically. Oocytes unfertilized after ICSI can be activated with the calcium ionophore A23187 to show two pronuclei and two polar bodies. Addition of rhGM-CSF in the culture medium of A23187-activated oocytes enhances their cleaving and blastulation potential and results in more euploid blastocysts compared to the culture medium alone. This study shows that activating post-ICSI aged human unfertilized oocytes with a combination of a calcium ionophore and a cytokine can produce good-morphology euploid blastocysts.

Artificial oocyte activation after intracytoplasmic morphologically selected sperm injection: A prospective randomized sibling oocyte study

This study aimed to evaluate the effect of artificial oocyte activation (AOA) by calcium ionophore after intracytoplasmic morphologically selected sperm injection (IMSI) on fertilization, cleavage rate and embryo quality. A total of 194 oocytes from 21 cycles from women with a history of low fertilization rate accompanying teratozoospermia were enrolled over a 3-month period. Mature oocytes from each patient were randomly allocated into two groups after IMSI. In the study group, half of the patients’ oocytes (n = 97) were exposed to AOA, and in the control group (n = 97), AOA was not applied. The mean number of mature oocytes, fertilization and cleavage rates were similar between the study and control groups (p > 0.05 for each). However, fertilized oocytes of the AOA group were less likely to produce top quality embryos when calculated per fertilized oocyte (28/80; 35.0% versus 38/71; 53.5%, respectively; p = 0.024) and also per cycle (13/21; 61.9% versus 20/21; 95.24%, respectively; p = 0.006). Our study indicates that AOA may not improve fertilization rates after IMSI and may even reduce the ability of a successfully fertilized oocyte to develop into a top quality embryo. AOA should, therefore, be applied to cases with a defined oocyte activating deficiency.