Assessment of the calcium releasing machinery in oocytes that failed to fertilize after conventional ICSI and assisted oocyte activation

Research question

Can oocyte-related activation deficiencies be evaluated in oocytes that failed to fertilize after intracytoplasmic sperm injection (ICSI) combined with assisted oocyte activation (AOA)?

Assisted oocyte activation effects on the morphokinetic pattern of derived embryos

ObjectiveAssisted oocyte activation (AOA) can restore fertilization rates after IVF/ICSI cycles with fertilization failure. AOA is an experimental technique, and its downstream effects remain poorly characterized. Clarifying the relationship between AOA and embryo, morphokinetics could offer complementary insights into the quality and viability of the embryos obtained with this technique. The aim of this study is to compare the preimplantation morphokinetic development of embryos derived from ICSI-AOA (experimental group) vs. ICSI cycles (control group).MethodsA retrospective cohort study was carried out with 141 embryos from fresh oocyte donation cycles performed between 2013 and 2017; 41 embryos were derived from 7 ICSI-AOA cycles and 100 embryos from 18 ICSI cycles. Morphokinetic development of all embryos was followed using a time-lapse system.ResultsWe show that embryos from both groups develop similarly for most milestones, with the exception of the time of second polar body extrusion (tPB2) and the time to second cell division (t3).ConclusionsWe conclude that ionomycin mediated AOA does not seem to affect the morphokinetic pattern of preimplantation embryo development, despite the alterations found in tPB2 and t3, which could directly reflect the use of a Ca²⁺ ionophore as a transient and quick non-physiologic increase of free intracytoplasmic Ca²⁺.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10815-020-02025-9.     

Effect of KN-62, a Selective Inhibitor of Calmodulin-Dependent Kinase II, On Mouse Oocyte Activation

Purpose: Our purpose was to determine the association of calmodulin-dependent protein kinase II (CaMK _II ) with oocyte activation and to explore the network of protein kinases during mammalian fertilization. Methods: Mouse M-II oocytes were collected after superovulation induced by PMSG-hCG injection. The oocytes were inseminated or artificially activated by Ca ionophore (A23187) or 12-O-tetradecanoyl phorbol 13-acetate (TPA). The effects of KN-62, a specific and selective inhibitor of calmodulin-dependent protein kinase II, on second polar body emission (2PBE), pronuclearformation (PF), and cortical granule exocytosis (CGE) during fertilization or after artificial oocyte activation were investigated. Results: KN-62 inhibited 2PBE and PF after sperm or Ca ionophore inducing activation. Additionally, PF was inhibited by KN-62 after TPA activation, whereas KN-62 did not inhibit CGE in any case. KN-04, an inactive form of KN-62, did not inhibit significantly 2PBE, CGE, or PF. When oocytes were exposed to KN-62 after Ca ionophore or TPA activation, no inhibitory effects on 2PBE or PF were observed. Conclusions: The CaMK _II activation that occurs after fertilization or artificial activation of mouse oocytes is presumably secondary to increases in the intracellular free calcium concentration. As determined by the use of inhibitor, CaMK _II activity is associated with 2PBE and PF but not with CGE.     

PLCζ disruption with complete fertilization failure in normozoospermia

PurposeIntracytoplasmic sperm injection (ICSI) is widely used to achieve fertilization in the presence of severe male factor, resulting in high fertilization rates. Nevertheless, 1–3 % of couples experience complete fertilization failure after ICSI. When a male factor is identified, assisted oocyte activation (AOA) can help overcome fertilization failures. The objective of this study is to describe a case of repeated complete fertilization failures after ICSI with donor oocytes, and to investigate the molecular and functional aspects of phospholipase C zeta (PLCζ) protein in the patient semen.MethodsThe patient was a normozoospermic male who had previously fathered, through natural conception, four children by a different partner. Molecular and functional analysis of sperm-specific PLCζ in the patient and control samples by means of gene sequencing, immunocytochemistry, Western blot, mouse oocyte activation test (MOAT), and mouse oocyte calcium analysis (MOCA) were used.ResultsPLCζ expression levels and distribution were significantly disrupted, although MOAT and MOCA did not indicate a decrease in activation ability.ConclusionsNormozoospermic males can have disrupted expression and distribution of PLCζ, and reduced activation ability after ICSI in human oocytes, despite their normal activation potential in functional testing using mouse oocytes. Discrepancy among molecular and functional data might exist, as mutations in the gene sequence may not be the only cause of alteration in PLCζ protein related to activation failures.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-015-0496-0) contains supplementary material, which is available to authorized users.     

Artificial oocyte activation improves cycles with prospects of ICSI fertilization failure: a sibling oocyte control study

Research questionDoes artificial oocyte activation improve clinical outcomes for patients at risk of intracytoplasmic sperm injection (ICSI) fertilization failure?DesignIn this study, sibling oocytes from patients with previous ICSI failure or severe teratozoospermia were divided equally into two groups, half for artificial oocyte activation (AOA) with ionomycin after conventional ICSI and the other half for conventional ICSI only (non-AOA). The fertilization rates, cleavage rates, transferable embryo rates and blastulation rates of the two groups were compared first; the clinical pregnancy and live birth rates were also compared to assess the efficiency and safety of AOA.ResultThe outcomes of the AOA group were significantly better than those of the conventional ICSI group in terms of the fertilization (50.38% versus 33.86%, respectively, P < 0.001), cleavage (59.16% versus 39.04%, respectively, P < 0.001) and transferable embryo rates (43.51% versus 26.69%, respectively, P < 0.001). The blastulation (43.53% versus 36.11%, respectively), implantation (26.83% versus 15.79%, respectively), clinical pregnancy (38.46% versus 25%, respectively) and live birth rates (38.46% versus 16.67%, respectively) were not significantly different.ConclusionThis study showed that AOA improved some aspects of cycles at risk of ICSI failure by increasing the fertilization and transferable embryo rates. But blastulation, pregnancy and implantation rates were not improved. The study is limited by its small size and absence of data on cumulative outcomes.     

Analysis of clinical outcomes with respect to spermatozoan origin after artificial oocyte activation with a calcium ionophore

Purpose

Fertilization failures have occurred repeatedly in reproductive centers after intracytoplasmic sperm injection (ICSI) and artificial oocyte activation (AOA) has been used to prevent it. This study was performed to investigate whether spermatozoan origin influences clinical outcomes of AOA with a calcium ionophore.

Methods

A total of 185 ICSI cycles with a history of no or low fertilization was included in this retrospective study. The outcomes of AOA after ICSI were compared with ejaculated-normal, ejaculated-oligo-astheno-terato or extracted-testicular spermatozoa.

Results

There were significant differences between the previous standard ICSI cycles and AOA cycles in the rate of fertilization and clinical outcomes among cases with different sperm origins. Thirty-eight healthy babies (20 singles and 18 twins, 29 cycles) were successfully delivered, and no congenital birth defects were observed.

Conclusions

Most patients with a no or low fertilization history obtained an increased fertilization rate and a positive clinical outcome with AOA regardless of the origin of spermatozoa.     

Artificial oocyte activation with ionomycin compared with A23187 among patients at risk of failed or impaired fertilization

Research questionDo fertilization rates differ between intracytoplasmic sperm injection (ICSI) cycles treated with artificial oocyte activation (AOA) using 10 µmol/l ionomycin or commercial A23187 in women at risk of failed or impaired fertilization?DesignThis single-centre, 7-year retrospective cohort study included 157 couples with a history of total fertilization failure (TFF, 0%) or low fertilization (<30%) after ICSI, or with severe oligo-astheno-teratozoospermia (OAT) in the male partner. Couples and underwent 171 ICSI–AOA cycles using either 10 µmol/l ionomycin or commercial A23187. The embryological and clinical outcomes were compared.ResultsFertilization rates in the ionomycin group were significantly higher than those in the A23187 group for all three subgroups (TFF, 46.9% versus 28.4%, P = 0.002; low fertilization, 67.7% versus 49.2%, P < 0.001; severe OAT, 66.4% versus 31.6%, P < 0.001). AOA with ionomycin significantly increased the day 3 cleavage rate (P = 0.009) when compared with A23187 in the low fertilization group, but not in the TFF or severe OAT group (both P > 0.05). The rates of day 3 good-quality embryos, clinical pregnancy, implantation and live birth, and the cumulative live birth, did not differ between the two groups (all P > 0.05). A total of 64 live births resulted in 72 healthy babies born.ConclusionsAOA with 10 µmol/l ionomycin may be more effective than commercial A23187 in improving oocyte activation in patients at risk of failed or impaired fertilization, especially in cases of sperm-related defects.     

卵母细胞激活技术在卵细胞质内单精子注射受精失败或低下患者中的应用

目的探讨卵母细胞激活技术在卵细胞质内单精子注射（ICSI）受精失败或低下患者和可疑受精失败或低下患者中的应用价值。方法选择2011年6月至2013年5月至少有1次ICSI受精失败或低下的患者lO例,再次接受助孕治疗时,实施卵母细胞激活技术（作为激活周期）;对可疑ICSI受精失败或低下患者3例,实施半数卵母细胞激活处理,将获得的67枚卵子分为常规ICSI组和激活组。观察卵母细胞激活前后的受精率、卵裂率和优质胚胎的变化及妊娠结局。结果在ICSI受精失败或低下患者中,既往周期的受精率为29．67％（27／91）,激活周期的受精率为72．58％（45／62）,两者比较,差异有统计学意义（P〈O．01）;既往周期和激活周期的卵裂率分别为85．19％（23／27）和95．56％（43／45）,两者比较,差异无统计学意义（P〉0．05）;优质胚胎量由既往IC$I周期的（0．25±0．45）个提高到激活周期的（1．18±1．33）个（P〈0．05）;5例患者获得临床妊娠。在可疑ICSI受精失败或低下患者中,常规ICSI组和激活组的受精率、卵裂率和优质胚胎量比较,差异均无统计学意义（P均〉0．05）。结论卵母细胞激活技术可提高ICSI受精失败或低下史患者的受精率,但是对于没有ICSI受精失败或低下史的患者效果不佳。     

Comparison Between Two hCG-to-Oocyte Aspiration Intervals on the Outcome of In Vitro Fertilization

Purpose: To determine whether there was any difference inthe outcome of in vitro fertilization when retrieval of oocyteswas done 34 hr (group A) or 38 hr (group B) after hCGinjection. Methods: A total of 170 patients with tubal failure wererandomized into either group A (83 patients) or group B(87 patients). They underwent in vitro fertilization accordingto described protocols and were compared with regard tothe frequency of spontaneous ovulation, number of oocytesretrieved, oocyte cumulus complex quality, embryo quality,and implantation and pregnancy rates. Results: There was no significant difference for any of theparameters tested for in group A and group B. Conclusions: HCG can be administered at any time withinthe time interval of 34 to 38 hr before retrieval of oocyteswithout affecting the results of in vitro fertilization.     

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.     

冻融后小鼠卵母细胞培养时间对ICSI结果的影响及受精失败辅助激活的结果

目的:研究冻存后的小鼠成熟卵母细胞复苏后培养不同时间对ICSI结果的影响,观察Ca2+载体霉素联合嘌呤霉素对ICSI受精失败的卵母细胞补救激活的有效性。方法:采用慢冻-快融程序化冷冻方法冻融小鼠成熟卵母细胞,复苏后卵母细胞分别培养不同时间(1h、2h、3h、4h、5h)后行ICSI,比较其受精和胚胎发育情况。冻融后受精失败的卵母细胞分为两组(A组:辅助激活,B组:不采取辅助激活),另外获取ICSI受精失败的新鲜卵母细胞(C组)采用和A组同样方法辅助激活,观察3组激活效果。结果:复苏的卵母细胞ICSI前培养3~4h后正常受精率、囊胚形成率明显高于培养1h、2h和5h实验组;A组激活率与B组相比,有明显差异(30.4%vs 6.7%,P<0.05);A组激活率和2PN2PB比例明显低于C组(30.4%vs 75.6%,P<0.05;21.4%vs 47.1%,P<0.05);A、C两组之间1PN2PB比例相比无统计学差异。结论:复苏的成熟卵母细胞ICSI前培养3~4 h后有助于卵母细胞结构的恢复,提高正常受精率和后期发育潜能。辅助激活在一定程度上可以挽救ICSI受精失败的卵母细胞;由于冻融损伤,复苏后ICSI受精失败的卵母细胞被辅助激活的能力明显下降。     

Artificial oocyte activation to improve reproductive outcomes in couples with various causes of infertility: a retrospective cohort study

Research questionDoes calcium ionophore treatment of oocytes improve fertilization rate, embryo development and outcomes in specific groups of infertile couples?DesignThis retrospective cohort study involved 796 couples undergoing oocyte activation with calcium ionophore (A23187) after intracytoplasmic sperm injection (ICSI) between 2016 and 2018. All metaphase II oocytes were exposed to 5 μmol/l ionophore for 15 min immediately after ICSI, cultured in vitro to the blastocyst stage, and transferred to the uteri of recipients on day 5 or cryopreserved for transfer in the next cycle. The previous cycles of the same patients formed the control group.ResultsAmong 1261 ICSI cycles and 796 ICSI-artificial oocyte activation (ICSI–AOA) cycles, implantation, positive beta-HCG, clinical pregnancy and live birth rates were significantly (P < 0.05 to P < 0.001) improved for all groups, compared with previous cycles, except live birth rate in women with primary ovarian insufficiency (POI). Compared with previous cycles, rates of blastulation (all P < 0.001) and high-quality blastocysts (P < 0.05 to P < 0.001) were increased significantly for couples with male factor (oligoasthenoteratozoospermia [OAT]), unexplained infertility and couples with both factors in the ICSI–AOA cycles. High-quality blastocyst rate was increased in couples with polycystic ovary syndrome (PCOS) (P = 0.0453). Miscarriage rates were decreased significantly (P < 0.05 to P < 0.001) in couples with OAT, PCOS and unexplained infertility in the treatment cycles. No significant differences were found for fertilization rate, embryo development or live birth rate in patients with POI between both groups.ConclusionsArtificial oocyte activation was able to ‘rescue’ the poor reproductive outcomes in certain types of infertile couples with history of failure to achieve pregnancy.     

Live birth after SrCl2 oocyte activation in previous repeated failed or low fertilization rates after ICSI of frozen-thawed testicular spermatozoa: case report

Purpose

To report a live birth resulting after strontium chloride (SrCl₂) oocyte activation in a couple with complete fertilization failure or low fertilization rates following intracytoplasmic sperm injection (ICSI) of frozen-thawed testicular spermatozoa.

Methods

The couple underwent ICSI of frozen-thawed testicular spermatozoa. After ICSI, the oocytes were artificially activated by SrCl₂ because the results of fertilization were not satisfactory in the previous cycles. The main outcome measures were fertilization, pregnancy, and birth.

Results

In the first and second cycles performed previously at another clinic, fertilization rates were 9.1 % and 0.0 %, respectively. In the third cycle, 31 metaphase II oocytes were retrieved. After sperm injection, all of the oocytes were stimulated using SrCl₂ for activation. Sixteen oocytes were fertilized (51.6 %), and a single embryo was transferred into the uterus on Day 3. A healthy girl weighing 2750 g was born at 40 weeks of gestation by caesarean section.

Conclusions

This result suggests that SrCl₂ could be useful for oocyte fertilization in case of repeated complete fertilization failure or low fertilization rates following ICSI of frozen-thawed testicular spermatozoa.     

Correlation between human follicular diameter and oocyte outcomes in an ICSI program

Purpose: To determine the correlation between the follicular sizes and oocyte recovery, metaphase II oocyte recovery, fertilization rate and good embryo quality from mature and immature oocytes in an intracytoplasmic sperm injection (ICSI) program. Methods: 991 follicles obtained from 72 ICSI cycles were classified into three groups according to their diameters as measured by transvaginal ultrasound including group A (<10 mm), group B (10–14 mm), and group C (>14 mm). All obtained oocytes were classified according to their nuclear maturation: germinal vesicle (GV), metaphase I (MI) and metaphase II (MII). Mature oocytes underwent ICSI while immature oocytes were further cultured until maturity before ICSI was performed. The rates of fertilization and good quality embryos at day 3 were evaluated. Results: A progressive and significant increase in the rates of oocyte recovery and MII oocyte recovery were observed from group A follicles compared to the other groups (p < 0.001). The fertilization rate of mature and in vitro matured oocytes, as well as the rate of good quality embryos showed a tendency to increase from group A to group C follicles, but not significantly. The corresponding fertilization rates were 78 and 55.3% (p < 0.001) for mature and in vitro matured oocytes, respectively. Conclusion: Collection of oocytes from small follicles, especially with a mean diameter less than 10 mm, and in vitro maturation of immature oocytes before fertilization may allow the total number of good quality and transferable embryos to be increased.     

Comparison of clinical outcomes between conventional in vitro fertilization and intracytoplasmic sperm injection in poor responders with only single oocyte retrieved

ObjectiveTo compare the clinical outcomes between conventional insemination (IVF) and intracytoplasmic sperm injection (ICSI) in poor responders with only a single oocyte retrieved.Materials and methodsThis is a retrospective case–control study. Couples who were treated with assisted reproductive technology (ART) with a single oocyte retrieved in Mackay Memorial Hospital from 1996 to 2016 were recruited. All data were categorized into three groups, according to their fertilization method and semen quality: group A, conventional insemination with non-male factor (IVF-NMF, n = 115), group B, ICSI with male factor (ICSI-MF, n = 30), and group C, ICSI with non-male factor (ICSI-NMF, n = 49).ResultsNo statistically significant difference was observed between IVF and ICSI groups in pregnancy outcomes, including the chemical or clinical pregnancy rate, miscarriage rate, and live birth rate. Similar fertilization rates per oocyte obtained were observed in IVF and ICSI patients, but significantly lower per mature oocyte in the ICSI group (IVF: 91.5%, ICSI-MF: 75.0%, ICSI-NMF: 77.8%). Although there is no statistical significance, the lower live birth rate is observed in group C than others (A:11.5%, B:25%, C:5%, p = 0.187).ConclusionIn this study, pregnancy outcomes of conventional in vitro fertilization and ICSI in poor responders with only a single oocyte retrieved were similar. However, the fertilization rate of matured oocytes in ICSI groups is significantly lower than that in the IVF group, indicating that ICSI procedures might cause oocyte damage. Therefore, the choice of fertilization method should be based on semen quality. A randomized controlled trial should be performed to confirm our findings.     

Cabergoline administration prevents development of moderate to severe ovarian hyperstimulation syndrome and it contributes to reduction in ovarian volume

PurposeThe aim of this study was to determine the prophylactic effects of cabergoline on ovarian hyperstimulation syndrome (OHSS) after oocyte retrieval.MethodsA total of 187 women underwent controlled ovarian stimulation using gonadotropin releasing hormone (GnRH) agonist long protocol or flexible GnRH antagonist protocol for in vitro fertilization. They responded excessively to ovulation induction, and fresh embryo transfers were canceled. Sixty‐one patients in the intervention group were administered oral cabergoline (0.5 mg) three times after oocyte retrieval (day 0, 2, and 4 following the oocyte retrieval). Ultrasonography and blood examination were performed on the seventh day following oocyte retrieval. The main outcomes measured were the incidence of OHSS, estimated ovarian volumes, ascites, hematocrits, and white blood cell counts.ResultsThe incidence of moderate to severe OHSS was lower after cabergoline administration (9.8 vs. 23.0 %, p = 0.03). The ovarian volumes reduced after intervention (96.2 vs. 145.5 cm³, p = 0.008). The reduction was evident in the patients with agonist long protocol (92.1 vs. 167.5 cm³, p = 0.0005). No significant differences were observed for other factors.ConclusionsCabergoline has a favorable effect on the prevention of moderate to severe OHSS affiliated with ovarian volume reduction.     

Do Alterations in the Sex Ratio Occur at Fertilization? A Case Report Using Fluorescent In Situ Hybridization

Purpose: The mechanisms by which the sex ratio might be altered at fertilization were reviewed, following a case of preimplantation gender analysis revealing a significantly skewed proportion of male-to-female embryos. Methods: The case of a known carrier of X-linked hydrocephalus with a history of three affected male pregnancies is presented. Her husband's family history consisted of a strong increase in the number of males relative to females. She had four cycles of stimulated in vitro fertilization, with sex chromosome analysis using fluorescent in situ hybridization (FISH) on suitable cleavage-stage embryos. The difference in the sex ratio of normal male-to-female embryos was compared using a significance probabilities test for sex ratio. The sex ratio of sperm from a semen sample from the male partner was determined by FISH. Results: Fifty embryos were suitable for analysis. A significantly higher number of normal male (n = 20) than normal female (n = 8) embryos was obtained (P < 0.05). The FISH assessment of the husband's semen analysis revealed no alteration in the normal X:Y ratio. Conclusions: As the sperm analysis revealed a normal X:Y ratio, an alteration in the embryo sex ratio might be explained by the preferential binding of Y-bearing sperm to the oocyte, an oocyte-related discouragement of binding of X-bearing sperm, or a postfertilization event.     

Efficiency of assisted oocyte activation as a solution for failed intracytoplasmic sperm injection

Failed fertilization after intracytoplasmic sperm injection (ICSI) can occur due to an oocyte activation defect. In these cases assisted oocyte activation (AOA) may help but efficiency is still unknown. Prior to AOA, the mouse oocyte activation test (MOAT) can be carried out by injecting human spermatozoa into mouse oocytes to evaluate their activating capacity. According to the MOAT activation percentage achieved, patients were classified into three groups: 0-20% (16 patients); 20-85% (seven patients); 85-100% (seven patients). For AOA, CaCl(2) was injected together with spermatozoa followed by a double Ca(2+) ionophore treatment. The fertilization rates before application of AOA in 50 cycles were 6%, 22% and 14% in, respectively, groups 1, 2 and 3 without any pregnancy. Fertilization and pregnancy rates after AOA in 61 cycles were significantly increased to 75% and 34% for group 1, 73% and 43% for group 2, and 75% and 17% for group 3 (P < 0.0001 and P < 0.004, respectively). Application of AOA results in normal fertilization and pregnancy rates in patients whose spermatozoa show deficient activation. When MOAT reveals no activation deficiency in spermatozoa, AOA still allows for high fertilization and acceptable pregnancy rates. The obstetric and neonatal outcomes after AOA were normal as no malformations were observed.     

An ultrastructural analysis of an oocyte from an in vitro fertilization patient with repeated polyspermic fertilization

Objective: Our goal was to determine any ultrastructural anomalies in an oocyte from a patient with a history of polyspermy. Results: Ultrastructural observations of the cortical ooplasm of several oocytes from each of three control patients showed a large population of intact cortical granules. Conversely, one oocyte from a patient with repeated polyspermic fertilization contained a relative paucity of granules in the cortex. Quantitative analysis of the cortices of control oocytes indicated that there were 17.02±0.52 cortical granules present per measured field of view, compared with 4.40±2.92 granules per field in the other oocyte. Conclusions: The presence of sufficient cortical granules is necessary for normal (monospermic) fertilization to occur. When contrasted to the cortical granule population of oocytes from several control patients, the cortex of one oocyte from the other patient showed few of these organelles. Therefore, the absence of a sufficient number of granules may have precluded normal fertilization from occurring in the eggs of this patient.     

Genetic analysis of embryo in a human case of spontaneous oocyte activation: a case report

Abstract

Parthenogenesis, a unique form of reproduction, is normally inhibited in mammals and a human embryo with parthenogenetic origin is not considered capable of producing offspring. The aim of this report is to analyze a parthenogenetic oocyte retrieved from a patient so as to have a better understanding on parthenogenesis and causes of infertility. A 38-year-old woman presented at our center with a history of primary infertility for 10?years and underwent an IVF-ICSI cycle. Three MII oocytes retrieved and one of which presented with 1 pronucleus before conducting ICSI and developed into an embryo 30?h post-retrieval. Blastomere biopsy, genome amplification, copy number variation (CNV) analysis and MultiSNPs analysis was performed on the embryo. The results showed that only one blastomere contains DNA and CNV analysis indicated a genotype of 48, XX, +17, +17 and the genetic contribution of biopsied embryo was of exclusively maternal origin. Such analysis might be beneficial for patients with a history of oocyte spontaneous activation in diagnosing case-specific aberrations and providing individualized therapeutic strategies such as preimplantation genetic diagnosis to choose a genetic normal embryo to transplant.