Correlation between three pro-nuclei (3PN) incidence and further embryo multinucleation at the two-cell stage (MN2) during IVF: A time-lapse study

Correlation between three pro-nuclei (3PN) incidence and further embryo multinucleation at the two-cell stage (MN2) during IVF: A time-lapse study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Correlation between three pro-nuclei (3PN) incidence and further embryo multinucleation at the two-cell stage (MN2) during IVF: A time-lapse study Mingzhao Li, Xia Xue, Juanzi Shi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4487381/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Nov, 2024 Read the published version in Scientific Reports → Version 1 posted 13 You are reading this latest preprint version Abstract The incidence of ≥ 3PN zygotes and blastomere multinucleation was found to be elevated in the presence of increased E 2 levels and a greater number of retrieved oocytes. This implies a potential link between the incidence of MN2 and a higher proportion of ≥ 3PN zygotes. We aimed to investigate the effect of high proportion of 3PN zygotes on MN2 incidence during IVF by using time-lapse monitoring (TLM). This study included 1195 patients with TLM from January 2020 to December 2022. The TLM patients were categorized into three groups: Group 1 comprised patients with no ≥ 3PN zygotes (n = 422), Group 2 included those with 0–25% ≥3PN zygotes (n = 617), and Group 3 consisted of patients with more than 25% ≥3PN zygotes (n = 156).The MN2 rate, types of MN2 and clinical outcomes were compared among the three groups. Our data indicated that the live birth rate was significantly higher in the group 2 than that in the group 3 (65.32 versus 56.41%; p = 0.039). The group 1 and 2 showed significantly lower MN2 rates than group 3 (18.33 and 19.45% versus 25.62%; p < 0.001). The MN2 embryos exhibited similar rates of high-quality embryos (42.27 versus 43.50 versus 40.67%; p = 0.401) and available embryos (84.96 versus 84.04 versus 83.21%; p = 0.460) rates among three groups. There were no significant differences in the proportion of MN2 with different types among the three groups ( p > 0.05). There were no significant differences in the blastocyst formation rates for embryos with different type of MN2 among the three groups ( p > 0.05). A high frequency of ≥ 3PN zygotes incidence might lead to a decrease in the rate of live births, and the occurrence of MN2 events could be predicted based on the ≥ 3PN zygotes incidence. Biological sciences/Developmental biology Health sciences/Endocrinology Health sciences/Medical research Multinucleation ≥3PN time-lapse clinical outcomes Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction The phenomenon of blastomere multinucleation at the two-cell stage (MN2) is a common nuclear abnormality observed in early human embryos 1 . The reported incidence of MN2 demonstrates a significant variation, ranging between 15% and 40% 2,3 . A blastomere exhibiting multiple nuclei has been observed to undergo independent dissolution of nuclear membranes, resulting in asynchronous nuclear events pivotal for cell division. Studies have reported that the incidence of MN2 exerts a considerable detrimental influence on embryo development, blastocyst formation, and successful implantation 4 . The incidence of ≥ 3PN is identified as one of the most prevalent chromosomal abnormalities impacting human gestation 5 . Prior research suggests a higher proportion of ≥ 3PN zygotes negatively influences embryo development and clinical outcomes in both conventional in vitro fertilization (C-IVF) and intracytoplasmic sperm injection (ICSI) cycles 6 , 7 . Sachs et al. demonstrated that the propensity toward ≥ 3PN was related to ovarian stimulation, as indicated by elevated peak E 2 levels and substantial oocyte yields 8 . Furthermore, several studies have indicated that cycles with multinucleation exhibited increased E 2 levels and a higher count of retrieved oocytes 9 , 10 . In our previous study, we selected two patients who had a single 2PN zygote and more than four ≥ 3PN zygotes in the initial C-IVF cycle. We then observed the incidence of MN2 in the single normal embryo utilizing time-lapse monitoring (TLM) 11 . These findings implied a potential association between the incidence of MN2 and a higher proportion of ≥ 3PN zygotes. Consequently, our study aimed to investigate the impact of a high proportion of ≥ 3PN zygotes on the incidence of MN2. Materials and methods This study encompassed 831 patients who underwent TLM from January 2020 to December 2022. Only elective single blastocyst embryo transfers (eSBETs) were included in this study. The TLM patients were categorized into three groups: Group 1 comprised patients with no ≥ 3PN zygotes (n = 422), Group 2 included those with 0–25% ≥3PN zygotes (n = 617), and Group 3 consisted of patients with more than 25% ≥3PN zygotes (n = 156). All female patients were not beyond 38 years old to eliminate possible age-related cycle characteristics. Additionally, all cycles were the first attempt at down-regulated ovarian stimulation. Patients with severe endometriosis, those using a gestational carrier, those undergoing in-vitro maturation, those with the presence of uninterrupted hydrosalpinx or intrauterine adhesions, and those with polycystic ovary syndrome were excluded from this study. The ovarian stimulation protocol employed in this study has been previously delineated 12 . Briefly, stimulation protocols were executed utilizing a combination of Gonadotropin-Releasing Hormone (GnRH) agonist/GnRH antagonist and recombinant Follicle-Stimulating Hormone (FSH). The ovarian response was continually monitored via serial ultrasound examinations and hormone measurements. Upon the detection of three follicles exceeding 18 mm, patients were administered 10,000 units of Human Chorionic Gonadotropin (hCG). Oocyte retrieval was subsequently executed 36 hours later through transvaginal ultrasonography-guided aspiration. Post-retrieval, the oocyte-cumulus complexes (OCCs) were cultured in IVF medium (Vitrolife, Sweden). Fertilization was performed 39 to 40 hours (39–42 hours for ICSI) after HCG administration while incubated in fertilization medium (IVF; Vitrolife). Five hours post-IVF fertilization, zygotes were transferred to a cleavage medium (G-1; Vitrolife). Embryos designated for blastocyst culture were moved to a blastocyst medium (G-2; Vitrolife) on day 3 and remained until day 6. All media were overlaid with paraffin oil and incubated in a humidified atmosphere at 37°C for a preceding duration of 24 hours. After 64 to 68 h of culture, the cleavage-stage embryos were scored according to homogeneous degree of blastomeres, the number of blastomeres and embryo fragmentation. The high-quality cleavage-stage embryos were graded I and II. The available cleavage-stage embryos were graded I, II, and III. The blastocyst-stage embryos were scored according to the stage of development from 1 to 6, the grade of the inner cell mass and the trophectoderm 13 . The high-quality blastocyst was graded ≥ 3BB. For culture with the EmbryoScope (Vitrolife, Sweden), dedicated 16-well plates were prepared with 25 µl microdrops of culture medium (Vitrolife, Sweden) overlaid by 1.4 ml of mineral oil (Vitrolife) at 37°C, in 6% CO 2 , 5% O 2 , and 89% N 2 . Retrospective analysis of each embryo's images was conducted using the EmbryoViewer external image analysis software (Unisense FertiliTech, Sweden). Images were acquired every 20 min in seven different focal planes during culture. The specific parameters were recorded according to relevant references 14 . The embryos exhibiting abnormal cleavage (division of one cell into three cells) or direct cleavage (duration of the 2-cell stage ≦ 5h) were omitted due to their recognized detrimental effect on implantation 15 . The ET catheter (Cook Ireland Ltd., Limerick, Ireland) was used for transfer. Prior to the transfer, any vaginal and cervical secretions were gently removed from the vagina/cervix with small pledgets of cotton wool, moistened with warm normal saline. Any mucus present in the cervical canal was also removed. Following the transfer, the catheter was examined for any retained embryos or presence of blood. Post-transfer, all patients received luteal support via Duphaston (progesterone injection). Clinical pregnancy was confirmed by the detection of an intrauterine gestational sac and fetal heartbeat via transvaginal ultrasound four weeks post-embryo transfer. The comparison of continuous variable outcomes between groups was conducted using the Student's t-test for normally distributed data and the non-parametric Mann-Whitney U-test for skewed data. Categorical variable outcomes, expressed as numbers and percentages, were compared between groups using the chi-square test or Fisher's exact test. The statistical analyses were performed utilizing SPSS version 21 (IBM Corp., USA). A p-value of less than 0.05 was considered to indicate statistical significance. Results The study flow chart was presented in Fig. 1 . The demographic and baseline characteristics of the study population were detailed in Table 1 . No significant differences were noted in the female age, BMI, duration of infertility, basal FSH level, basal E 2 level, total Gn dose, Gn stimulation duration, number of retrieved oocytes, and endometrial thickness ( p > 0.05). Table 1 Main characteristics of the study population. Continuous variables were presented as mean ± standard deviation. Categorical variables were expressed as number and percentage. BMI: body mass index; FSH: follicle-stimulating hormone; E 2 : estradiol; Gn: gonadotropin. Parameter Group 1 Group 2 Group 3 P No. transfers (n) 422 617 156 / Female’s age (y) 30.17 ± 3.50 30.08 ± 3.75 30.36 ± 3.95 0.695 BMI (kg/m 2 ) 21.93 ± 3.51 22.03 ± 3.56 22.24 ± 3.58 0.287 Infertile time (y) 2.97 ± 1.22 2.99 ± 1.31 3.03 ± 1.35 0.702 Basal FSH (mIU/ml) 6.53 ± 1.32 6.61 ± 1.42 6.72 ± 1.49 0.303 Basal E 2 (pg/ml) 61.55 ± 21.02 63.29 ± 22.11 62.52 ± 21.83 0.291 Total Gn does (IU) 2203.70 ± 863.78 2146.17 ± 819.64 2108.57 ± 770.99 0.282 Gn stimulation time (d) 11.28 ± 2.83 11.24 ± 2.66 11.31 ± 2.59 0.751 No. of oocytes retrieved (n) 11.70 ± 2.70 12.93 ± 2.86 12.18 ± 2.77 0.239 Endometrial thickness (mm) 11.91 ± 2.30 11.97 ± 2.37 12.03 ± 2.41 0.763 We observed no significant differences in the clinical pregnancy (70.14 versus 72.12 versus 66.67%; p = 0.180), ectopic pregnancy (0.68 versus 0.45 versus 0.96%; p = 0.524) and ongoing pregnancy (64.93 versus 66.77 versus 61.54%; p = 0.218) rates among the three groups. Our data showed that the live birth was significantly higher in the group 2 than that in the group 3 (65.32 versus 56.41%; p = 0.039) (Table 2 ). There were no significant differences observed in the rates of direct cleavage (DC) (26.29 versus 25.09 versus 23.52%; p = 0.069) and reverse cleavage (RC) (5.90 versus 6.00 versus 6.41%; p = 0.617) rates among the three groups. The results indicated that the MN2 rate was significantly lower in groups 1 and 2 compared to group 3 (18.33 and 19.45 versus 25.62%; p < .001) (Table 3 ). The MN2 embryos exhibited similar rates of high-quality embryos (42.27 versus 43.50 versus 40.67%; p = 0.401) and available embryos (84.96 versus 84.04 versus 83.21%; p = 0.460) rates among three groups (Table 4 ). The blastomeres’ nucleus status at the two-cell stage was shown in Fig. 2 . There were no significant differences in the proportion of MN2 with different types among the three groups ( p > 0.05) (Table 4 ). The type of MN2 mainly displayed in three forms, namely 2BI1, 2MULTI1 and 2MULTI2. There were no significant differences in the blastocyst formation rates for embryos with different type of MN2 among the three groups ( p > 0.05) (Table 4 ). Table 2 Clinical outcomes of the population. * was significantly different. Parameter Group 1 Group 2 Group 3 P No. transfers (n) 422 617 156 / Clinical pregnancy (%,n) 70.14 (296/422) 72.12 (445/617) 66.67 (104/156) 0.180 Ectopic pregnancy (%,n) 0.68 (2/296) 0.45 (2/445) 0.96 (1/104) 0.524 Ongoing pregnancy (%,n) 64.93 (274/422) 66.77 (412/617) 61.54 (96/156) 0.218 Live birth (%,n) 62.32 (263/422) 65.32 (403/617)* 56.41 (88/156)* 0.039 Table 3 Results of 2PN embryo developmental parameters from TLS. TLS: time-lapse system; 2PN: two pronuclei; DC: direct cleavage; RC: reverse cleavage; MN2: multinucleation at the two-cell stage; a vs a , b vs b , c vs c were significantly different. Parameter Group 1 Group 2 Group 3 P No. transfers (n) 422 617 156 / 2PN (%,n) 79.17 (3910/4939) a,b 72.54 (5786/7976) a,c 56.05 (1065/1900) b,c < 0.001 Cleavage (%,n) 98.36 (3846/3910) 98.45 (5696/5786) 98.22 (1046/1065) 0.584 DC (%,n) 26.29 (1011/3846) 25.09 (1429/5696) 23.52 (246/1046) 0.069 RC (%,n) 5.90 (227/3846) 6.00 (342/5696) 6.41 (67/1046) 0.617 MN2 (%,n) 18.33 (705/3846) a 19.45 (1108/5696) b 25.62 (268/1046) a,b < 0.001 Table 4 Correlation between nucleus status at the two-cell stage and blastocyst development. Parameter Group 1 Group 2 Group 3 P No. MN2 embryos (n) 705 1108 268 / D3 good quality embryos (%,n) 42.27 (298/705) 43.50 (482/1108) 40.67 (109/268) 0.401 D3 available embryos (%,n) 84.96 (599/705) 84.04 (927/1108) 83.21 (223/268) 0.460 Types of MN2 (%,n) 0.305 2BI1 30.2 (213/705) 28.4 (315/1108) 26.9 (72/268) 2BI2 2.7 (19/705) 2.7 (30/1108) 3.0 (8/268) 2MULTI1 31.9 (225/705) 30.9 (342/1108) 32.1 (86/268) 2BI1/2MULTI1 5.4 (38/705) 7.0 (77/1108) 4.9 (13/268) 2MULT2 29.8 (210/705) 31.0 (344/1108) 33.2 (89/268) Blastocyst formation (%,n) 0.500 2BI1 61.0 (130/213) 58.0 (183/315) 61.1 (44/72) 2BI2 52.6 (10/19) 46.7 (14/30) 50.0 (4/8) 2MULTI1 58.2 (131/225) 60.5 (207/342) 58.1 (50/86) 2BI1/2MULTI1 57.9 (22/38) 57.1 (44/77) 61.5 (8/13) 2MULTI2 46.7 (98/210) 44.5 (153/344) 46.0 (41/89) The blastocyst formation rates were 59.5% for 2BI1 embryos, 64% for 2BI2 embryos, 51.7% for 2MULTI1 embryos, 57.8% for 2BI1/2MULTI1 and 45.4% for 2MULTI2 embryos (Fig. 3 ). Transfer characteristics as well as the distribution of nucleus status at the two-cell stage were shown in Table 5 . Elective single blastocyst embryo transfer was mostly from 2MONO embryo (Table 5 ). There were no significant differences in the clinical pregnancy rates for all transfers with different type of MN2 among the three groups (p > 0.05) (Table 6 ). Our date also demonstrated that blastocysts displaying 2BI1 and 2BI2 had similar implantation potential compared with that from normal embryos. Blastocysts displaying other types of MN2 were correlated with a reduced implantation potential compared to 2MONO embryos after blastocyst transfer (Fig. 4 ). Table 5 Results of nucleus status at the two-cell stage for all transfers Parameter Group 1 Group 2 Group 3 No. transfers (n) 422 617 156 2MONO (%,n) 63.7 (269/422) 60.3 (372/617) 59.6 (93/156) 2BI1 (%,n) 12.6 (53/422) 14.3 (88/617) 13.5 (21/156) 2BI2 (%,n) 3.08 (13/422) 3.73 (23/617) 3.85 (6/156) 2MULTI1 (%,n) 11.6 (49/422) 12.8 (79/617) 12.2 (19/156) 2MULTI2 (%,n) 6.40 (27/422) 7.3 (45/617) 8.97 (14/156) 2BI1/2MULTI2 (%,n) 2.61 (11/422) 1.62 (10/617) 1.92 (3/156) Table 6 Clinical outcomes of all transfers with different nucleus status at the two-cell stage. Parameter Group 1 Group 2 Group 3 Clinical pregnancy (%,n) 70.14 (296/422) 72.12 (445/617) 66.67 (104/156) 2MONO (%,n) 73.2 (197/269) 75.5 (281/372) 71.0 (66/93) 2BI1 (%,n) 73.6 (39/53) 76.1 (67/88) 66.7 (14/21) 2BI2 (%,n) 69.2 (9/13) 73.9 (17/23) 83.3 (5/6) 2MULTI1 (%,n) 63.3 (31/49) 62.0 (49/79) 57.9 (11/19) 2MULTI2 (%,n) 55.6 (15/27) 55.6 (25/45) 50.0 (7/14) 2BI1/2MULTI2 (%,n) 45.5 (5/11) 60.0 (6/10) 33.3 (1/3) Discussion The etiology of ≥ 3PN incidence was complicated which were primarily attributed to oocyte-derived meiotic failure and polyspermic fertilization. Sachs et al. clearly illustrated that the occurrence of ≥ 3PN was associated with a heightened response to gonadotropin stimulation, characterized by elevated peak E 2 level on the day of hCG administration and a high number of retrieved oocytes 8 . Physiologically, patients with a robust response to the drug frequently yielded a higher proportion of immature or overripe oocytes. Immature oocytes were unable to undergo proper cortical and zona reactions, leading to an elevated rate of polyspermy. After aging of overripe egg, only part or no cortical granules might be released. It resulted in incomplete or unsuccessful cortical reaction, thereby increasing the likelihood of polyspermy occurrence. Multinucleation was a nuclear abnormality resulting from an error in the cytokinesis process 16 . Jackson et al. found multinucleation present in cycles that exhibited a heightened response to treatment, characterized by elevated E 2 levels and a high number of retrieved oocytes 9 . Figueira et al. demonstrated that most of the patients experiencing MN2 incidence exhibited a greater quantity of follicles and retrieved oocytes 10 . These observations suggested that multinucleated embryos might result from ovulation induction regimens in which the ovaries were more sensitive to gonadotrophin therapy, leading to increased oocyte production. Some oocytes generated in these exuberant cycles seemed to be abnormal, potentially resulting in chromosomal abnormalities, cytokinesis errors, and multinucleation 9 , 17 . To sum up, elevated peak serum E 2 level and a higher number of retrieved oocytes might be associated with the incidence of ≥ 3PN zygotes and MN2 embryos. The way a single embryo was affected might indicate how the entire cohort was affected, even if the remaining embryos did not exhibit similar characteristics. It also suggested that a high proportion of ≥ 3PN zygotes could increase the likelihood of MN2 embryos occurrence originating from surplus 2PN zygotes. Subsequently, our findings revealed a positive correlation between the MN2 rate and the incidence of ≥ 3PN embryos. Figueira et al. showed that a high proportion of ≥ 3PN zygotes might reflect a globally dysfunctional oocyte cohort and make negative influence on the embryo potential development 6 . A retrospective analysis of cleavage-stage embryos also indicated that the appearance of MN2 was associated with impaired cleavage and increased fragmentation 18 . Nevertheless, we observed comparable good-quality and available embryo rates in groups with high proportion of ≥ 3PN zygotes compared with groups with low or absent ≥ 3PN zygotes in this investigation. Conflicting conclusions might be due to the capacity for self-correction during initial cleavage divisions. Balakier et al. demonstrated a significant decrease in the blastomere multinucleation rate during the transition from the 2- to 4-cell stage 4 . In this study, we noted a decrease in the MN rate of almost 3% in groups without 3PN zygotes and 11% in groups with a high proportion of ≥ 3PN zygotes during the transition from the 2- to 4-cell stage. The potential for self-correction was also proposed in earlier FISH studies, which revealed that some MN2 embryos might restore normal ploidy during preimplantation development 19 . Our research also revealed that the live birth rate decreased and the MN2 rate increased in the population with a high proportion of ≥ 3PN zygotes. We further investigated the nucleus status at the two-cell stage for all transfers and our findings showed that elective single blastocyst embryo transfer was predominantly from those embryos with one nucleus in each blastomere. Our findings indicated that MN2 mainly displayed in three forms: 2BI1, 2MULTI1 and 2MULTI2 which was consistent with previous report 20 . In this study, embryos exhibiting 2BI1 and 2BI1/2MULTI1 showed a comparable blastocyst formation rate to that of 2MONO embryos. Embryos exhibiting 2BI1 and 2MULTI1 showed enhanced development leading to the formation of high-quality blastocysts in comparison to other types of MN2 embryos. Similar to our research, Talbot et al. also indicated that embryos displaying 2BI1 were correlated with enhanced development resulting in the formation of high-quality blastocysts 20 . The relationship between multinucleation and aneuploidy remains unclear. Studies utilizing preimplantation genetic screening have indicated similar aneuploidy rates between embryos with multinucleation and those without multinucleation 21 . Hence, it has been proposed that the presence of multinucleation at the two-cell stage should not be considered as a reliable indicator of aneuploidy or for embryo selection. It has been suggested that most MN2 embryos have the capacity for self-correction during early cleavage divisions and can develop into euploid blastocysts resulting in healthy babies 4 . It was also illustrated that blastocysts derived from MN2 embryos exhibited comparable implantation potential to those from normal embryos 22 . Our study also indicated that blastocysts with 2BI1 and 2BI2 exhibited comparable implantation potential to that of normal embryos. Therefore, these findings suggest that culture of MN2 embryos to the blastocyst stage for transfer might be an alternative option. It is difficult to predict the potential for embryo development into a blastocyst and the potential for successful implantation in the cleavage-stage embryo transfers. It is worth noting that there are differences in the implantation rates of blastocysts from different types of MN2. Based on our data, if we need to transfer the MN2 embryos at the cleavage-stage, we highly recommend the embryos exhibiting 2BI1 at the two-cell stage since 2BI1 embryos have a greater propensity to develop into blastocysts. In conclusion, a high frequency of ≥ 3PN zygotes incidence might lead to a decrease in the rate of live births, and the occurrence of MN2 events could be predicted based on the ≥ 3PN zygotes incidence. Our results emphasized the importance of differentiating the subgroups of multinucleated embryos at the two-cell stage. The types of MN2 had significant reference value when selecting embryos for transfer during the cleavage stage. Declarations Ethics approval and consent to participate All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. This study was approved by the Ethics Review Board of the Northwest Women’ s and Children’ s Hospital, Xi’ an, China (2022007). Competing interests The authors declare that there is no conflict of interest. Author Contribution M.L. and J.S. designed the research; M.L. and X.X. performed the research. X.X. analyzed the data; All authors contributed to editorial changes in the manuscript. All authors read and approved the final manuscript. All authors have participated sufficiently in the work and agreed to be accountable for all aspects of the work. Data Availability Data available on request corresponding author due to privacy and ethical restrictions. References Hardy, K. et al . Binucleate blastomeres in preimplantation human embryos in vitro: failure of cytokinesis during early cleavage. J Reprod Fertil. 98, 549–558 (1993). Yilmaz, A. et al . Chromosomal complement and clinical relevance of multinucleated embryos in PGD and PGS cycles. Reprod Biomed Online. 28, 380–387 (2014). Sun, L. et al . Chromosomal polymorphisms are independently associated with multinucleated embryo formation. J Assist Reprod Genet. 35, 149–156 (2018). Balakier, H. et al . Impact of multinucleated blastomeres on embryo developmental competence, morphokinetics, and aneuploidy. Fertil Steril . 106, 608 – 14 (2016). McFadden D.E. et al . Phenotype of triploid embryos. J Med Genet. 43, 609–612 (2005). Figueira R.C. et al . Prognostic value of triploid zygotes on intracytoplasmic sperm injection outcomes. J Assist Reprod Genet. 28, 879–883 (2011). Li M.Z. et al . Effects of triploidy incidence on clinical outcomes for IVF-ET cycles in different ovarian stimulation protocols. Gynecol Endocrinol. 31, 769–773 (2015). Sachs A.R. et al . Factors associated with the formation of triploid zygotes after intracytoplasmic sperm injection. Fertil Steril. 73, 1109–1114 (2000). Jackson K.V. et al . Multinucleation in normally fertilized embryos is associated with an accelerated ovulation induction response and lower implantation and pregnancy rates in in vitro fertilization-embryo transfer cycles. Fertil Steril. 70, 60–66 (1998). Figueira R.C. et al . Blastomere multinucleation: Contributing factors and effects on embryo development and clinical outcome. Hum Fertil (Camb). 13, 143–150 (2010). Li M.Z. et al . High three pro-nuclei (3PN) zygotes proportion associated with normal embryo multinucleation at the two-cell stage: two cases report. Gynecol Endocrinol. 36, 1042–1044 (2020). Shi W.H. et al . Factors related to clinical pregnancy after vitrified-warmed embryo transfer: a retrospective and multivariate logistic regression analysis of 2313 transfer cycles. Hum Reprod. 28, 1768–75 (2013). Luna M. et al . Human blastocyst morphological quality is significantly improved in embryos classified as fast on day 3 (> or = 10 cells), bringing into question current embryological dogma. Fertil Steril. 89, 358–363 (2008). Kim H.J. et al . Evaluation of human embryo development in in vitro fertilization and intracytoplasmic sperm injection fertilized oocytes: a time-lapse study. Clin Exp Reprod Med. 44, 90–95 (2017). Rubio I. et al . Limited implantation success of direct-cleaved human zygotes: a time-lapse study. Fertil Steril. 98, 1458–1463 (2012). Meriano J. et al . Binucleated and micronucleated blastomeres in embryos derived from human assisted reproduction cycles. Reprod Biomed Online. 9, 511–520 (2004). Haaf T. et al . A high oocyte yield for intracytoplasmic sperm injection treatment is associated with an increased chromosome error rate. Fertil Steril. 91, 733–738 (2009). Van Royen E. et al . Multinucleation in cleavage stage embryos. Hum Reprod. 18, 1062–1069 (2003). Staessen C. et al . The genetic constitution of multinuclear blastomeres and their derivative daughter blastomeres. Hum Reprod, 13, 1625–1631 (1998). Talbot A.L. et al . Binucleated embryos at the two-cell stage show higher blastocyst formation rates and higher pregnancy and live birth rates compared to non-multinucleated embryos. Hum Reprod Open . 2022, hoac049 (2022). Desai N. et al . Analysis of embryo morphokinetics, multinucleation and cleavage anomalies using continuous time-lapse monitoring in blastocyst transfer cycles. Reprod Biol Endocrinol. 12, 54 (2014). Akiyoshi E. et al . Developmental capacity and implantation potential of the embryos with multinucleated blastomeres. J Reprod Dev. 61, 595–600 (2015). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 03 Nov, 2024 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 13 Sep, 2024 Reviews received at journal 10 Sep, 2024 Reviews received at journal 09 Sep, 2024 Reviewers agreed at journal 09 Sep, 2024 Reviewers agreed at journal 03 Sep, 2024 Reviewers agreed at journal 12 Jul, 2024 Reviewers agreed at journal 16 Jun, 2024 Reviewers agreed at journal 03 Jun, 2024 Reviewers invited by journal 03 Jun, 2024 Editor assigned by journal 03 Jun, 2024 Editor invited by journal 29 May, 2024 Submission checks completed at journal 29 May, 2024 First submitted to journal 27 May, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4487381","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":312136914,"identity":"cdb9e866-5dac-4902-94e6-40322f302339","order_by":0,"name":"Mingzhao Li","email":"","orcid":"","institution":"Northwest Women’s and Children’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mingzhao","middleName":"","lastName":"Li","suffix":""},{"id":312136917,"identity":"85a26b32-ba8d-4fe9-b5f4-0632d03141e8","order_by":1,"name":"Xia Xue","email":"","orcid":"","institution":"Northwest Women’s and Children’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xia","middleName":"","lastName":"Xue","suffix":""},{"id":312136921,"identity":"b5446e10-9aa5-475a-b42e-937e7bd59c49","order_by":2,"name":"Juanzi Shi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsklEQVRIiWNgGAWjYNACHgY5Nvb2A6RpMebjOZNAmj2J8yQcDIhTKt9//JnkD5m69DYJhgSGHxXbCGsxOHAg2ZiHhy23TbrxAGPPmdtEaGFsOPiYgYcnt03mQAIzYxsRWuSbgXp+8Eiks0kkGBCnheEYM+MDHh6DBOK1GJxhYwb6JcGwDRjIB4nyCzjEfvbUycu3tx988KOCGIeBAGMPhD5ApHoQ+EGC2lEwCkbBKBh5AABl/jVqASBJ6gAAAABJRU5ErkJggg==","orcid":"","institution":"Northwest Women’s and Children’s Hospital","correspondingAuthor":true,"prefix":"","firstName":"Juanzi","middleName":"","lastName":"Shi","suffix":""}],"badges":[],"createdAt":"2024-05-28 01:23:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4487381/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4487381/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-024-78342-1","type":"published","date":"2024-11-03T16:20:11+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":58231732,"identity":"528e438b-a495-4060-bae4-8530dab8af9f","added_by":"auto","created_at":"2024-06-12 19:30:28","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":21524,"visible":true,"origin":"","legend":"\u003cp\u003eStudy Flow Chart.\u003c/p\u003e\n\u003cp\u003eeSBET: elective single blastocyst-stage embryo transfer; MN2: multinucleation at the two-cell stage; 2MONO: non-multinucleated at the two-cells tage; 2BI1: binucleated at the two-cell stage in one blastomere; 2BI2: binucleated at the two-cell stage in both blastomere; 2MULTI1: true multinucleated at the two-cell stage in one blastomere; 2BI1/2MULTI1: binucleated in one blastomere and true multinucleatedin the other blastomere at the two-cell stage; 2MULTI2: true multinucleated at the two-cell stage in both blastomeres; Group 1: the patients with no ≥3PN zygotes; Group 2: the patients with 0-25% ≥3PN zygotes; Group 3: the patients with more than 25% ≥3PN zygotes.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4487381/v1/76a7e20ae2962de51c5e2c41.png"},{"id":58230836,"identity":"7a801bf9-609d-4647-9b90-1cc51ed1a32c","added_by":"auto","created_at":"2024-06-12 19:22:28","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":36923,"visible":true,"origin":"","legend":"\u003cp\u003eNucleus status at the two-cell stage.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4487381/v1/787f24e12bae4163cf129e2b.png"},{"id":58230838,"identity":"5c943279-7538-4c8a-91d6-c59db62e3576","added_by":"auto","created_at":"2024-06-12 19:22:28","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":37915,"visible":true,"origin":"","legend":"\u003cp\u003eBlastocyst formation of different types of MN2 embryos\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4487381/v1/7c5f3f379c31af3b82902a14.png"},{"id":58231733,"identity":"a87815dc-11d1-48c8-8983-34e6f1df26d3","added_by":"auto","created_at":"2024-06-12 19:30:28","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":48515,"visible":true,"origin":"","legend":"\u003cp\u003eImplantation ability of different types of MN2 embryos\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4487381/v1/c15242c7537015c32ad90e2e.png"},{"id":68207172,"identity":"3d4d7ce1-feb3-4b65-872b-a3fc650da389","added_by":"auto","created_at":"2024-11-04 16:35:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":645223,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4487381/v1/c3521f4b-f548-40d2-bb12-03f373c8f1d8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Correlation between three pro-nuclei (3PN) incidence and further embryo multinucleation at the two-cell stage (MN2) during IVF: A time-lapse study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe phenomenon of blastomere multinucleation at the two-cell stage (MN2) is a common nuclear abnormality observed in early human embryos\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. The reported incidence of MN2 demonstrates a significant variation, ranging between 15% and 40%\u003csup\u003e2,3\u003c/sup\u003e. A blastomere exhibiting multiple nuclei has been observed to undergo independent dissolution of nuclear membranes, resulting in asynchronous nuclear events pivotal for cell division. Studies have reported that the incidence of MN2 exerts a considerable detrimental influence on embryo development, blastocyst formation, and successful implantation\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe incidence of \u0026ge;\u0026thinsp;3PN is identified as one of the most prevalent chromosomal abnormalities impacting human gestation\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Prior research suggests a higher proportion of \u0026ge;\u0026thinsp;3PN zygotes negatively influences embryo development and clinical outcomes in both conventional in vitro fertilization (C-IVF) and intracytoplasmic sperm injection (ICSI) cycles\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSachs et al. demonstrated that the propensity toward \u0026ge;\u0026thinsp;3PN was related to ovarian stimulation, as indicated by elevated peak E\u003csub\u003e2\u003c/sub\u003e levels and substantial oocyte yields\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Furthermore, several studies have indicated that cycles with multinucleation exhibited increased E\u003csub\u003e2\u003c/sub\u003e levels and a higher count of retrieved oocytes\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. In our previous study, we selected two patients who had a single 2PN zygote and more than four\u0026thinsp;\u0026ge;\u0026thinsp;3PN zygotes in the initial C-IVF cycle. We then observed the incidence of MN2 in the single normal embryo utilizing time-lapse monitoring (TLM)\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. These findings implied a potential association between the incidence of MN2 and a higher proportion of \u0026ge;\u0026thinsp;3PN zygotes. Consequently, our study aimed to investigate the impact of a high proportion of \u0026ge;\u0026thinsp;3PN zygotes on the incidence of MN2.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003eThis study encompassed 831 patients who underwent TLM from January 2020 to December 2022. Only elective single blastocyst embryo transfers (eSBETs) were included in this study. The TLM patients were categorized into three groups: Group 1 comprised patients with no\u0026thinsp;\u0026ge;\u0026thinsp;3PN zygotes (n\u0026thinsp;=\u0026thinsp;422), Group 2 included those with 0\u0026ndash;25% \u0026ge;3PN zygotes (n\u0026thinsp;=\u0026thinsp;617), and Group 3 consisted of patients with more than 25% \u0026ge;3PN zygotes (n\u0026thinsp;=\u0026thinsp;156). All female patients were not beyond 38 years old to eliminate possible age-related cycle characteristics. Additionally, all cycles were the first attempt at down-regulated ovarian stimulation. Patients with severe endometriosis, those using a gestational carrier, those undergoing in-vitro maturation, those with the presence of uninterrupted hydrosalpinx or intrauterine adhesions, and those with polycystic ovary syndrome were excluded from this study.\u003c/p\u003e \u003cp\u003eThe ovarian stimulation protocol employed in this study has been previously delineated \u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Briefly, stimulation protocols were executed utilizing a combination of Gonadotropin-Releasing Hormone (GnRH) agonist/GnRH antagonist and recombinant Follicle-Stimulating Hormone (FSH). The ovarian response was continually monitored via serial ultrasound examinations and hormone measurements. Upon the detection of three follicles exceeding 18 mm, patients were administered 10,000 units of Human Chorionic Gonadotropin (hCG). Oocyte retrieval was subsequently executed 36 hours later through transvaginal ultrasonography-guided aspiration.\u003c/p\u003e \u003cp\u003ePost-retrieval, the oocyte-cumulus complexes (OCCs) were cultured in IVF medium (Vitrolife, Sweden). Fertilization was performed 39 to 40 hours (39\u0026ndash;42 hours for ICSI) after HCG administration while incubated in fertilization medium (IVF; Vitrolife). Five hours post-IVF fertilization, zygotes were transferred to a cleavage medium (G-1; Vitrolife). Embryos designated for blastocyst culture were moved to a blastocyst medium (G-2; Vitrolife) on day 3 and remained until day 6. All media were overlaid with paraffin oil and incubated in a humidified atmosphere at 37\u0026deg;C for a preceding duration of 24 hours.\u003c/p\u003e \u003cp\u003eAfter 64 to 68 h of culture, the cleavage-stage embryos were scored according to homogeneous degree of blastomeres, the number of blastomeres and embryo fragmentation. The high-quality cleavage-stage embryos were graded I and II. The available cleavage-stage embryos were graded I, II, and III. The blastocyst-stage embryos were scored according to the stage of development from 1 to 6, the grade of the inner cell mass and the trophectoderm \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. The high-quality blastocyst was graded\u0026thinsp;\u0026ge;\u0026thinsp;3BB.\u003c/p\u003e \u003cp\u003eFor culture with the EmbryoScope (Vitrolife, Sweden), dedicated 16-well plates were prepared with 25 \u0026micro;l microdrops of culture medium (Vitrolife, Sweden) overlaid by 1.4 ml of mineral oil (Vitrolife) at 37\u0026deg;C, in 6% CO\u003csub\u003e2\u003c/sub\u003e, 5% O\u003csub\u003e2\u003c/sub\u003e, and 89% N\u003csub\u003e2\u003c/sub\u003e. Retrospective analysis of each embryo's images was conducted using the EmbryoViewer external image analysis software (Unisense FertiliTech, Sweden). Images were acquired every 20 min in seven different focal planes during culture. The specific parameters were recorded according to relevant references \u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. The embryos exhibiting abnormal cleavage (division of one cell into three cells) or direct cleavage (duration of the 2-cell stage\u0026thinsp;≦\u0026thinsp;5h) were omitted due to their recognized detrimental effect on implantation \u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe ET catheter (Cook Ireland Ltd., Limerick, Ireland) was used for transfer. Prior to the transfer, any vaginal and cervical secretions were gently removed from the vagina/cervix with small pledgets of cotton wool, moistened with warm normal saline. Any mucus present in the cervical canal was also removed. Following the transfer, the catheter was examined for any retained embryos or presence of blood. Post-transfer, all patients received luteal support via Duphaston (progesterone injection). Clinical pregnancy was confirmed by the detection of an intrauterine gestational sac and fetal heartbeat via transvaginal ultrasound four weeks post-embryo transfer.\u003c/p\u003e \u003cp\u003eThe comparison of continuous variable outcomes between groups was conducted using the Student's t-test for normally distributed data and the non-parametric Mann-Whitney U-test for skewed data. Categorical variable outcomes, expressed as numbers and percentages, were compared between groups using the chi-square test or Fisher's exact test. The statistical analyses were performed utilizing SPSS version 21 (IBM Corp., USA). A p-value of less than 0.05 was considered to indicate statistical significance.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe study flow chart was presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The demographic and baseline characteristics of the study population were detailed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. No significant differences were noted in the female age, BMI, duration of infertility, basal FSH level, basal E\u003csub\u003e2\u003c/sub\u003e level, total Gn dose, Gn stimulation duration, number of retrieved oocytes, and endometrial thickness (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMain characteristics of the study population. Continuous variables were presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. Categorical variables were expressed as number and percentage. BMI: body mass index; FSH: follicle-stimulating hormone; E\u003csub\u003e2\u003c/sub\u003e: estradiol; Gn: gonadotropin.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGroup 3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. transfers (n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e422\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e617\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u0026rsquo;s age (y)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.17\u0026thinsp;\u0026plusmn;\u0026thinsp;3.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.08\u0026thinsp;\u0026plusmn;\u0026thinsp;3.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.36\u0026thinsp;\u0026plusmn;\u0026thinsp;3.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.695\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.93\u0026thinsp;\u0026plusmn;\u0026thinsp;3.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.03\u0026thinsp;\u0026plusmn;\u0026thinsp;3.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.24\u0026thinsp;\u0026plusmn;\u0026thinsp;3.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfertile time (y)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.702\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBasal FSH (mIU/ml)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.72\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.303\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBasal E\u003csub\u003e2\u003c/sub\u003e (pg/ml)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.55\u0026thinsp;\u0026plusmn;\u0026thinsp;21.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e63.29\u0026thinsp;\u0026plusmn;\u0026thinsp;22.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e62.52\u0026thinsp;\u0026plusmn;\u0026thinsp;21.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.291\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal Gn does (IU)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2203.70\u0026thinsp;\u0026plusmn;\u0026thinsp;863.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2146.17\u0026thinsp;\u0026plusmn;\u0026thinsp;819.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2108.57\u0026thinsp;\u0026plusmn;\u0026thinsp;770.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.282\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGn stimulation time (d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.28\u0026thinsp;\u0026plusmn;\u0026thinsp;2.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.24\u0026thinsp;\u0026plusmn;\u0026thinsp;2.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.31\u0026thinsp;\u0026plusmn;\u0026thinsp;2.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.751\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of oocytes retrieved (n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.70\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.93\u0026thinsp;\u0026plusmn;\u0026thinsp;2.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.18\u0026thinsp;\u0026plusmn;\u0026thinsp;2.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.239\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEndometrial thickness (mm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.91\u0026thinsp;\u0026plusmn;\u0026thinsp;2.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.97\u0026thinsp;\u0026plusmn;\u0026thinsp;2.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.03\u0026thinsp;\u0026plusmn;\u0026thinsp;2.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.763\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eWe observed no significant differences in the clinical pregnancy (70.14 versus 72.12 versus 66.67%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.180), ectopic pregnancy (0.68 versus 0.45 versus 0.96%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.524) and ongoing pregnancy (64.93 versus 66.77 versus 61.54%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.218) rates among the three groups. Our data showed that the live birth was significantly higher in the group 2 than that in the group 3 (65.32 versus 56.41%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.039) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). There were no significant differences observed in the rates of direct cleavage (DC) (26.29 versus 25.09 versus 23.52%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.069) and reverse cleavage (RC) (5.90 versus 6.00 versus 6.41%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.617) rates among the three groups. The results indicated that the MN2 rate was significantly lower in groups 1 and 2 compared to group 3 (18.33 and 19.45 versus 25.62%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.001) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The MN2 embryos exhibited similar rates of high-quality embryos (42.27 versus 43.50 versus 40.67%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.401) and available embryos (84.96 versus 84.04 versus 83.21%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.460) rates among three groups (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The blastomeres\u0026rsquo; nucleus status at the two-cell stage was shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. There were no significant differences in the proportion of MN2 with different types among the three groups (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The type of MN2 mainly displayed in three forms, namely 2BI1, 2MULTI1 and 2MULTI2. There were no significant differences in the blastocyst formation rates for embryos with different type of MN2 among the three groups (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical outcomes of the population. * was significantly different.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGroup 3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. transfers (n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e422\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e617\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClinical pregnancy (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70.14 (296/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72.12 (445/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e66.67 (104/156)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.180\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEctopic pregnancy (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.68 (2/296)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.45 (2/445)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.96 (1/104)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.524\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOngoing pregnancy (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.93 (274/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.77 (412/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61.54 (96/156)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.218\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLive birth (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e62.32 (263/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65.32 (403/617)*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56.41 (88/156)*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.039\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of 2PN embryo developmental parameters from TLS. TLS: time-lapse system; 2PN: two pronuclei; DC: direct cleavage; RC: reverse cleavage; MN2: multinucleation at the two-cell stage; \u003csup\u003ea\u003c/sup\u003evs\u003csup\u003ea\u003c/sup\u003e, \u003csup\u003eb\u003c/sup\u003evs\u003csup\u003eb\u003c/sup\u003e, \u003csup\u003ec\u003c/sup\u003evs\u003csup\u003ec\u003c/sup\u003e were significantly different.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGroup 3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. transfers (n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e422\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e617\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2PN (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e79.17 (3910/4939)\u003csup\u003ea,b\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72.54 (5786/7976)\u003csup\u003ea,c\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56.05 (1065/1900)\u003csup\u003eb,c\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleavage (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e98.36 (3846/3910)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98.45 (5696/5786)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e98.22 (1046/1065)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.584\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDC (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.29 (1011/3846)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.09 (1429/5696)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.52 (246/1046)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.069\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRC (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.90 (227/3846)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.00 (342/5696)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.41 (67/1046)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.617\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMN2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.33 (705/3846)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.45 (1108/5696)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25.62 (268/1046)\u003csup\u003ea,b\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCorrelation between nucleus status at the two-cell stage and blastocyst development.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGroup 3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. MN2 embryos (n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e705\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1108\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e268\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eD3 good quality embryos (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.27 (298/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.50 (482/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40.67 (109/268)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.401\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eD3 available embryos (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e84.96 (599/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84.04 (927/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e83.21 (223/268)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.460\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTypes of MN2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003e0.305\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.2 (213/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.4 (315/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.9 (72/268)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.7 (19/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.7 (30/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.0 (8/268)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.9 (225/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.9 (342/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.1 (86/268)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1/2MULTI1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.4 (38/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.0 (77/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.9 (13/268)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29.8 (210/705)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.0 (344/1108)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e33.2 (89/268)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlastocyst formation (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003e0.500\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.0 (130/213)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58.0 (183/315)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61.1 (44/72)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.6 (10/19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e46.7 (14/30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50.0 (4/8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e58.2 (131/225)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60.5 (207/342)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58.1 (50/86)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1/2MULTI1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57.9 (22/38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57.1 (44/77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61.5 (8/13)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46.7 (98/210)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44.5 (153/344)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e46.0 (41/89)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe blastocyst formation rates were 59.5% for 2BI1 embryos, 64% for 2BI2 embryos, 51.7% for 2MULTI1 embryos, 57.8% for 2BI1/2MULTI1 and 45.4% for 2MULTI2 embryos (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Transfer characteristics as well as the distribution of nucleus status at the two-cell stage were shown in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. Elective single blastocyst embryo transfer was mostly from 2MONO embryo (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). There were no significant differences in the clinical pregnancy rates for all transfers with different type of MN2 among the three groups (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). Our date also demonstrated that blastocysts displaying 2BI1 and 2BI2 had similar implantation potential compared with that from normal embryos. Blastocysts displaying other types of MN2 were correlated with a reduced implantation potential compared to 2MONO embryos after blastocyst transfer (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of nucleus status at the two-cell stage for all transfers\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGroup 3\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. transfers (n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e422\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e617\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MONO (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e63.7 (269/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60.3 (372/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e59.6 (93/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.6 (53/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.3 (88/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.5 (21/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.08 (13/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.73 (23/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.85 (6/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI1 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.6 (49/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.8 (79/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.2 (19/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.40 (27/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.3 (45/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.97 (14/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1/2MULTI2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.61 (11/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.62 (10/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.92 (3/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical outcomes of all transfers with different nucleus status at the two-cell stage.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGroup 3\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClinical pregnancy (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70.14 (296/422)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e72.12 (445/617)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e66.67 (104/156)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MONO (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e73.2 (197/269)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e75.5 (281/372)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e71.0 (66/93)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e73.6 (39/53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e76.1 (67/88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e66.7 (14/21)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e69.2 (9/13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e73.9 (17/23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e83.3 (5/6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI1 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e63.3 (31/49)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e62.0 (49/79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e57.9 (11/19)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2MULTI2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e55.6 (15/27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e55.6 (25/45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e50.0 (7/14)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2BI1/2MULTI2 (%,n)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e45.5 (5/11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e60.0 (6/10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e33.3 (1/3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe etiology of \u0026ge;\u0026thinsp;3PN incidence was complicated which were primarily attributed to oocyte-derived meiotic failure and polyspermic fertilization. Sachs et al. clearly illustrated that the occurrence of \u0026ge;\u0026thinsp;3PN was associated with a heightened response to gonadotropin stimulation, characterized by elevated peak E\u003csub\u003e2\u003c/sub\u003e level on the day of hCG administration and a high number of retrieved oocytes\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Physiologically, patients with a robust response to the drug frequently yielded a higher proportion of immature or overripe oocytes. Immature oocytes were unable to undergo proper cortical and zona reactions, leading to an elevated rate of polyspermy. After aging of overripe egg, only part or no cortical granules might be released. It resulted in incomplete or unsuccessful cortical reaction, thereby increasing the likelihood of polyspermy occurrence.\u003c/p\u003e \u003cp\u003eMultinucleation was a nuclear abnormality resulting from an error in the cytokinesis process\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. Jackson et al. found multinucleation present in cycles that exhibited a heightened response to treatment, characterized by elevated E\u003csub\u003e2\u003c/sub\u003e levels and a high number of retrieved oocytes\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Figueira et al. demonstrated that most of the patients experiencing MN2 incidence exhibited a greater quantity of follicles and retrieved oocytes \u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. These observations suggested that multinucleated embryos might result from ovulation induction regimens in which the ovaries were more sensitive to gonadotrophin therapy, leading to increased oocyte production. Some oocytes generated in these exuberant cycles seemed to be abnormal, potentially resulting in chromosomal abnormalities, cytokinesis errors, and multinucleation\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eTo sum up, elevated peak serum E\u003csub\u003e2\u003c/sub\u003e level and a higher number of retrieved oocytes might be associated with the incidence of \u0026ge;\u0026thinsp;3PN zygotes and MN2 embryos. The way a single embryo was affected might indicate how the entire cohort was affected, even if the remaining embryos did not exhibit similar characteristics. It also suggested that a high proportion of \u0026ge;\u0026thinsp;3PN zygotes could increase the likelihood of MN2 embryos occurrence originating from surplus 2PN zygotes. Subsequently, our findings revealed a positive correlation between the MN2 rate and the incidence of \u0026ge;\u0026thinsp;3PN embryos.\u003c/p\u003e \u003cp\u003eFigueira et al. showed that a high proportion of \u0026ge;\u0026thinsp;3PN zygotes might reflect a globally dysfunctional oocyte cohort and make negative influence on the embryo potential development\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. A retrospective analysis of cleavage-stage embryos also indicated that the appearance of MN2 was associated with impaired cleavage and increased fragmentation\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Nevertheless, we observed comparable good-quality and available embryo rates in groups with high proportion of \u0026ge;\u0026thinsp;3PN zygotes compared with groups with low or absent\u0026thinsp;\u0026ge;\u0026thinsp;3PN zygotes in this investigation. Conflicting conclusions might be due to the capacity for self-correction during initial cleavage divisions. Balakier et al. demonstrated a significant decrease in the blastomere multinucleation rate during the transition from the 2- to 4-cell stage\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. In this study, we noted a decrease in the MN rate of almost 3% in groups without 3PN zygotes and 11% in groups with a high proportion of \u0026ge;\u0026thinsp;3PN zygotes during the transition from the 2- to 4-cell stage. The potential for self-correction was also proposed in earlier FISH studies, which revealed that some MN2 embryos might restore normal ploidy during preimplantation development\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eOur research also revealed that the live birth rate decreased and the MN2 rate increased in the population with a high proportion of \u0026ge;\u0026thinsp;3PN zygotes. We further investigated the nucleus status at the two-cell stage for all transfers and our findings showed that elective single blastocyst embryo transfer was predominantly from those embryos with one nucleus in each blastomere. Our findings indicated that MN2 mainly displayed in three forms: 2BI1, 2MULTI1 and 2MULTI2 which was consistent with previous report\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. In this study, embryos exhibiting 2BI1 and 2BI1/2MULTI1 showed a comparable blastocyst formation rate to that of 2MONO embryos. Embryos exhibiting 2BI1 and 2MULTI1 showed enhanced development leading to the formation of high-quality blastocysts in comparison to other types of MN2 embryos. Similar to our research, Talbot et al. also indicated that embryos displaying 2BI1 were correlated with enhanced development resulting in the formation of high-quality blastocysts\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe relationship between multinucleation and aneuploidy remains unclear. Studies utilizing preimplantation genetic screening have indicated similar aneuploidy rates between embryos with multinucleation and those without multinucleation\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. Hence, it has been proposed that the presence of multinucleation at the two-cell stage should not be considered as a reliable indicator of aneuploidy or for embryo selection.\u003c/p\u003e \u003cp\u003eIt has been suggested that most MN2 embryos have the capacity for self-correction during early cleavage divisions and can develop into euploid blastocysts resulting in healthy babies\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. It was also illustrated that blastocysts derived from MN2 embryos exhibited comparable implantation potential to those from normal embryos\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e. Our study also indicated that blastocysts with 2BI1 and 2BI2 exhibited comparable implantation potential to that of normal embryos. Therefore, these findings suggest that culture of MN2 embryos to the blastocyst stage for transfer might be an alternative option.\u003c/p\u003e \u003cp\u003eIt is difficult to predict the potential for embryo development into a blastocyst and the potential for successful implantation in the cleavage-stage embryo transfers. It is worth noting that there are differences in the implantation rates of blastocysts from different types of MN2. Based on our data, if we need to transfer the MN2 embryos at the cleavage-stage, we highly recommend the embryos exhibiting 2BI1 at the two-cell stage since 2BI1 embryos have a greater propensity to develop into blastocysts. In conclusion, a high frequency of \u0026ge;\u0026thinsp;3PN zygotes incidence might lead to a decrease in the rate of live births, and the occurrence of MN2 events could be predicted based on the \u0026ge;\u0026thinsp;3PN zygotes incidence. Our results emphasized the importance of differentiating the subgroups of multinucleated embryos at the two-cell stage. The types of MN2 had significant reference value when selecting embryos for transfer during the cleavage stage.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eEthics approval and consent to participate\u003c/h2\u003e \u003cp\u003e All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. This study was approved by the Ethics Review Board of the Northwest Women\u0026rsquo; s and Children\u0026rsquo; s Hospital, Xi\u0026rsquo; an, China (2022007).\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCompeting interests\u003c/strong\u003e \u003cp\u003eThe authors declare that there is no conflict of interest.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eM.L. and J.S. designed the research; M.L. and X.X. performed the research. X.X. analyzed the data; All authors contributed to editorial changes in the manuscript. All authors read and approved the final manuscript. All authors have participated sufficiently in the work and agreed to be accountable for all aspects of the work.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData available on request corresponding author due to privacy and ethical restrictions.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHardy, K. \u003cem\u003eet al\u003c/em\u003e. Binucleate blastomeres in preimplantation human embryos in vitro: failure of cytokinesis during early cleavage. J Reprod Fertil. 98, 549\u0026ndash;558 (1993).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYilmaz, A. \u003cem\u003eet al\u003c/em\u003e. Chromosomal complement and clinical relevance of multinucleated embryos in PGD and PGS cycles. Reprod Biomed Online. 28, 380\u0026ndash;387 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun, L. \u003cem\u003eet al\u003c/em\u003e. Chromosomal polymorphisms are independently associated with multinucleated embryo formation. J Assist Reprod Genet. 35, 149\u0026ndash;156 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBalakier, H. \u003cem\u003eet al\u003c/em\u003e. Impact of multinucleated blastomeres on embryo developmental competence, morphokinetics, and aneuploidy. \u003cem\u003eFertil Steril\u003c/em\u003e. 106, 608\u0026thinsp;\u0026ndash;\u0026thinsp;14 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcFadden D.E. \u003cem\u003eet al\u003c/em\u003e. Phenotype of triploid embryos. J Med Genet. 43, 609\u0026ndash;612 (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFigueira R.C. \u003cem\u003eet al\u003c/em\u003e. Prognostic value of triploid zygotes on intracytoplasmic sperm injection outcomes. J Assist Reprod Genet. 28, 879\u0026ndash;883 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi M.Z. \u003cem\u003eet al\u003c/em\u003e. Effects of triploidy incidence on clinical outcomes for IVF-ET cycles in different ovarian stimulation protocols. Gynecol Endocrinol. 31, 769\u0026ndash;773 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSachs A.R. \u003cem\u003eet al\u003c/em\u003e. Factors associated with the formation of triploid zygotes after intracytoplasmic sperm injection. Fertil Steril. 73, 1109\u0026ndash;1114 (2000).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJackson K.V. \u003cem\u003eet al\u003c/em\u003e. Multinucleation in normally fertilized embryos is associated with an accelerated ovulation induction response and lower implantation and pregnancy rates in in vitro fertilization-embryo transfer cycles. Fertil Steril. 70, 60\u0026ndash;66 (1998).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFigueira R.C. \u003cem\u003eet al\u003c/em\u003e. Blastomere multinucleation: Contributing factors and effects on embryo development and clinical outcome. Hum Fertil (Camb). 13, 143\u0026ndash;150 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi M.Z. \u003cem\u003eet al\u003c/em\u003e. High three pro-nuclei (3PN) zygotes proportion associated with normal embryo multinucleation at the two-cell stage: two cases report. Gynecol Endocrinol. 36, 1042\u0026ndash;1044 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShi W.H. \u003cem\u003eet al\u003c/em\u003e. Factors related to clinical pregnancy after vitrified-warmed embryo transfer: a retrospective and multivariate logistic regression analysis of 2313 transfer cycles. Hum Reprod. 28, 1768\u0026ndash;75 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuna M. \u003cem\u003eet al\u003c/em\u003e. Human blastocyst morphological quality is significantly improved in embryos classified as fast on day 3 (\u0026gt;\u0026thinsp;or =\u0026thinsp;10 cells), bringing into question current embryological dogma. Fertil Steril. 89, 358\u0026ndash;363 (2008).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim H.J. \u003cem\u003eet al\u003c/em\u003e. Evaluation of human embryo development in in vitro fertilization and intracytoplasmic sperm injection fertilized oocytes: a time-lapse study. Clin Exp Reprod Med. 44, 90\u0026ndash;95 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRubio I. \u003cem\u003eet al\u003c/em\u003e. Limited implantation success of direct-cleaved human zygotes: a time-lapse study. Fertil Steril. 98, 1458\u0026ndash;1463 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeriano J. \u003cem\u003eet al\u003c/em\u003e. Binucleated and micronucleated blastomeres in embryos derived from human assisted reproduction cycles. Reprod Biomed Online. 9, 511\u0026ndash;520 (2004).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHaaf T. \u003cem\u003eet al\u003c/em\u003e. A high oocyte yield for intracytoplasmic sperm injection treatment is associated with an increased chromosome error rate. Fertil Steril. 91, 733\u0026ndash;738 (2009).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Royen E. \u003cem\u003eet al\u003c/em\u003e. Multinucleation in cleavage stage embryos. Hum Reprod. 18, 1062\u0026ndash;1069 (2003).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStaessen C. \u003cem\u003eet al\u003c/em\u003e. The genetic constitution of multinuclear blastomeres and their derivative daughter blastomeres. Hum Reprod, 13, 1625\u0026ndash;1631 (1998).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTalbot A.L. \u003cem\u003eet al\u003c/em\u003e. Binucleated embryos at the two-cell stage show higher blastocyst formation rates and higher pregnancy and live birth rates compared to non-multinucleated embryos. \u003cem\u003eHum Reprod Open\u003c/em\u003e. 2022, hoac049 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDesai N. \u003cem\u003eet al\u003c/em\u003e. Analysis of embryo morphokinetics, multinucleation and cleavage anomalies using continuous time-lapse monitoring in blastocyst transfer cycles. Reprod Biol Endocrinol. 12, 54 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAkiyoshi E. \u003cem\u003eet al\u003c/em\u003e. Developmental capacity and implantation potential of the embryos with multinucleated blastomeres. J Reprod Dev. 61, 595\u0026ndash;600 (2015).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Multinucleation, ≥3PN, time-lapse, clinical outcomes","lastPublishedDoi":"10.21203/rs.3.rs-4487381/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4487381/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe incidence of \u0026ge;\u0026thinsp;3PN zygotes and blastomere multinucleation was found to be elevated in the presence of increased E\u003csub\u003e2\u003c/sub\u003e levels and a greater number of retrieved oocytes. This implies a potential link between the incidence of MN2 and a higher proportion of \u0026ge;\u0026thinsp;3PN zygotes. We aimed to investigate the effect of high proportion of 3PN zygotes on MN2 incidence during IVF by using time-lapse monitoring (TLM). This study included 1195 patients with TLM from January 2020 to December 2022. The TLM patients were categorized into three groups: Group 1 comprised patients with no\u0026thinsp;\u0026ge;\u0026thinsp;3PN zygotes (n\u0026thinsp;=\u0026thinsp;422), Group 2 included those with 0\u0026ndash;25% \u0026ge;3PN zygotes (n\u0026thinsp;=\u0026thinsp;617), and Group 3 consisted of patients with more than 25% \u0026ge;3PN zygotes (n\u0026thinsp;=\u0026thinsp;156).The MN2 rate, types of MN2 and clinical outcomes were compared among the three groups. Our data indicated that the live birth rate was significantly higher in the group 2 than that in the group 3 (65.32 versus 56.41%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.039). The group 1 and 2 showed significantly lower MN2 rates than group 3 (18.33 and 19.45% versus 25.62%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The MN2 embryos exhibited similar rates of high-quality embryos (42.27 versus 43.50 versus 40.67%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.401) and available embryos (84.96 versus 84.04 versus 83.21%; p\u0026thinsp;=\u0026thinsp;0.460) rates among three groups. There were no significant differences in the proportion of MN2 with different types among the three groups (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). There were no significant differences in the blastocyst formation rates for embryos with different type of MN2 among the three groups (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). A high frequency of \u0026ge;\u0026thinsp;3PN zygotes incidence might lead to a decrease in the rate of live births, and the occurrence of MN2 events could be predicted based on the \u0026ge;\u0026thinsp;3PN zygotes incidence.\u003c/p\u003e","manuscriptTitle":"Correlation between three pro-nuclei (3PN) incidence and further embryo multinucleation at the two-cell stage (MN2) during IVF: A time-lapse study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-12 19:22:23","doi":"10.21203/rs.3.rs-4487381/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-09-13T04:50:39+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-10T13:07:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-09T16:52:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"25244755814867759415089036770394484299","date":"2024-09-09T08:26:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"245502729560159610143732382835961151651","date":"2024-09-03T18:59:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"256587798497152277869719040842446256326","date":"2024-07-13T03:55:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"220476608463463403162542525822278198043","date":"2024-06-16T14:20:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"143982489124148877603899894518599116895","date":"2024-06-03T17:31:44+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-03T17:26:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-06-03T12:16:12+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-05-29T06:44:04+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-05-29T06:18:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-05-28T01:17:01+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e2594025-9649-4215-b928-4678481192c3","owner":[],"postedDate":"June 12th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":32993229,"name":"Biological sciences/Developmental biology"},{"id":32993230,"name":"Health sciences/Endocrinology"},{"id":32993231,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2024-11-04T16:26:00+00:00","versionOfRecord":{"articleIdentity":"rs-4487381","link":"https://doi.org/10.1038/s41598-024-78342-1","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-11-03 16:20:11","publishedOnDateReadable":"November 3rd, 2024"},"versionCreatedAt":"2024-06-12 19:22:23","video":"","vorDoi":"10.1038/s41598-024-78342-1","vorDoiUrl":"https://doi.org/10.1038/s41598-024-78342-1","workflowStages":[]},"version":"v1","identity":"rs-4487381","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4487381","identity":"rs-4487381","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}