Efficiency Comparison Between Dry And Humid Cultures For Clinical Outcome of The In Vitro Fertilization-Embryo Transfer

Efficiency Comparison Between Dry And Humid Cultures For Clinical Outcome of The In Vitro Fertilization-Embryo Transfer | 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 Research Article Efficiency Comparison Between Dry And Humid Cultures For Clinical Outcome of The In Vitro Fertilization-Embryo Transfer Weihai Xu, Lin Zhang, Ling Zhang, Shishi Li, Jing Shu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-335124/v2 This work is licensed under a CC BY 4.0 License Status: Posted Version 2 posted You are reading this latest preprint version Show more versions Abstract Background: In this study, we compared the in vitro embryo development, embryo transfer outcome and the offspring outcome in the in vitro fertilization-embryo transfer (IVF-ET) between dry culture (DC) and humid culture (HC). Methods: Our study was divided into two parts. Firstly, we determined the fertilization rate, cleavage rate and high-quality embryo rate from 21 cycles in the DC group (N=262 oocytes) and HC group (N=263 oocytes). Secondly, we determined the embryo transfer outcome and the offspring outcome in DC group (N=184 cycles) and HC group (N=136 cycles). Results: Compared with the HC group, significant increase was observed in the high-quality embryo rate (66.1.2% vs. 55.3%, p =0.037) and implantation rate (49.8% vs. 40.6%, p =0.027) in the DC group. No statistical differences were observed in the pregnant outcome and birth defect of the offspring ( p >0.05). Compared with HC, DC was associated with a higher high-quality embryo rate and a higher implantation rate after embryo transfer. Conclusions: No statistical differences were noticed in the offspring conditions between the two culture modes. Taken together, DC may serve as a promising method for IVF-ET. Maternal & Fetal Medicine Embryo culture In-vitro fertilization embryo transfer osmotic pressure Background In vitro fertilization-embryo transfer (IVF-ET) is considered a promising treatment option for the infertile couples. Its core element is to achieve IVF and select embryos with developmental potency for the transfer and/or cryopreservation. For a long time, humid culture (HC) has been conventionally utilized for the in vitro embryo culture. It provides a saturated humidity in the culture environment for embryo by means of water vaporization in an active manner or humidification based on disposable humidification flask. On this basis, the osmotic pressure of culture medium is stable [1, 2], contributing to the culture of zygote and embryo. Therefore, it is recommended as the major method for embryo culture [3]. As a new technique, dry culture (DC) has been used in the human embryo culture. Unlike the HC inducing generation of microorganisms that may affect the embryonic growth, DC involving a relatively dry environment can reduce the risks of microorganism growth [4]. In addition, by integrating with the Time-Lapse Imagine (TLI) technique, DC promotes the comprehensive monitoring of the embryonic growth. To date, few studies have been carried out to investigate the efficiency of DC in clinical settings [5, 6]. In a previous study, Fawzy et al indicated that the developed high-quality embryo rate on day 3 was significantly lower in the DC group than in the HC group (65% vs. 83%, p < 0.0001) [7]. In contrast, Elqusi et al reported that the high-quality blastocyst rate in the DC group was significantly higher than that of the HC group (62.9% vs. 43.5%) [8]. Furthermore, little is known about the effects of DC on the outcome of embryo transfer and offspring. In this study, we compared the effects of DC and HC on the offspring and evaluated the feasibility of the IVF-ET on the DC and HC. Methods Ethics approval and consent to participate This study was approved by the Reproductive Ethics Committee of Zhejiang Provincial People's Hospital (Protocol # SZ2016013). Written informed consent was obtained from each patient. Devices The EC6-230LE dry incubator (Astec, Japan) and APM-50 D humid incubator (Astec, Japan) were used in this study. The temperature, CO 2 and O 2 concentration were determined per day before the experiments. Subjects The IVF-ET related data were collected from 501 subjects presenting to the Reproductive Medicine Center, Zhejiang Provincial People’s Hospital between November 2016 and October 2017. The inclusion criteria were as follows: (i) female aged ≤38 yrs; (ii) those received frozen-thawed embryo transfer (FET) as the first embryo transfer; (iii) those received transfer of D3 high-quality embryos. Those with the following conditions were excluded from this study: (i) any individual of the couples presenting chromosomal anomaly; (ii) those with rescue intracytoplasmic sperm injection (ICSI) cycles after the IVF. Experimental design Twenty-one cycles with oocytes retrieval of ≥20 was collected in this study. The oocytes in each cycle were randomly divided into DC group (N=262 oocytes) and HC group (N=263 oocytes). Then we determined the in vitro culture efficiency including the fertilization rate, cleavage rate and high-quality embryo rate. In order to eliminate the effects of other factors on the clinical outcome, we analyzed the clinical outcome of the embryo and offspring conditions based on different culture model. Eventually, 352 cycles met the inclusion criteria, and 320 cycles were finally included in this study, consisting of DC group (N=184) and HC group (N=136), after excluding 5 with female chromosome abnormality, 5 with male chromosome abnormality, and 22 with rescue ICSI. IVF therapy The oocytes retrieval, IVF and embryo culture were conducted in our lab using the GnRH antagonist protocol, long protocol, and minimal stimulation protocol according to the previous description [9, 10]. The follicle-stimulating hormone (FSH), human menopause gonadotropin (HMG) and clomiphene were utilized to stimulate the follicular development according to the ovary reserve and response. In cases of a diameter of >17 mm in two follicles, or a diameter of >18 mm in one follicle, human chorionic gonadotrophin (HCG) and/or GnRH-a were administrated, followed by oocytes retrieval within 36-38 hrs. In order to avoid the influences of repetitive door open during the culture procedure, the chamber was performed independently for the in vitro culture cycle. The COOK sequential media (Cook Medical, Brisbane, Australia) was utilized for the IVF and embryo culture. The droplets prepared based on fertilization medium (FM, 80µl) and cleavage medium (CM, 30µl) were transferred to petri dishes (60×15, 353652, Falcon), followed by covering with 8.5 ml embryo culture oil (ART-4008-5P, Origio). Upon oocytes retrieval, conventional IVF or ICSI was performed. On day 3, the high-quality embryo was selected according to the ASBIR criteria [11] for the subsequent embryo cryopreservation. The endometrial preparation protocol of the FET cycle consists of natural cycle, hormone replacement therapy protocol and ovarian stimulation protocol. Based on the endometrium development conditions, one or two D3 high-quality frozen embryo was thawed, followed by transfer. Then the serum HCG was measured on day 12 to determine whether the female was pregnant. The clinical pregnancy was defined as presence of gestational sac by B-ultrasonography on day 35 after transfer. Those presenting no fetal heart or loss of fetal heart at week 12 were defined as early abortion. Ongoing pregnancy was defined as development of gestational sac for at least 12 weeks. Statistical analysis SPSS 19.0 software was used for the data analysis. Measurement data that were normally distributed were presented as mean ± standard deviation. Inter-group comparison was conducted using Student’s t-test. The comparison of numeration data was conducted using the Chi square test. Multi-variate logistic regression analysis was used to analyze the effects of female age, fertilization protocol, number of transferred embryos, and the culture mode on the pregnancy. p <0.05 was statistically significant. Results Comparison of fertilization rate, cleavage rate and high-quality embryo rate in sibling oocyte The fertilization rate in the DC group showed10 no statistical difference compared with the HC group (69.8% vs. 68.8%, p >0.05, Table 1 ). Meanwhile, there were no differences in the rate of cleavage between the two groups (98.4% vs. 98.9%, p >0.05). The high-quality embryo rate in the DC group was significantly higher than that of the HC group (66.1% vs. 55.3%, p =0.036). Table 1 In vitro culture results for the 21 IVF cycles Index DC mode HC mode t or x 2 p value Oocyte number 262 263 Fertility rate, % 69.8 68.8 0.065 0.799 Cleavage rate, % 98.4 98.9 0.176 0.675 High-quality embryo rate, % 66.1 55.3 4.392 0.036 Clinical outcome for the embryo transfer Compared with the DC group, there were no statistical differences in the age of the couple, infertility duration, previous history of pregnancy, causes of infertility, BMI, ovarian stimulation protocol, fertilization protocol and endometrial preparation protocol in the HC group ( p >0.05, Table 2 ). The number of transferred embryo in the DC group was significantly lower than that of the HC group (1.73±0.44 vs. 1.87±0.34, p =0.004). The implantation rate of embryo in the DC group was significantly higher than that of the HC group (49.8% vs. 40.6%, p =0.027). After adjusting the female age, endometrial preparation protocol, fertilization protocol and number of transferred embryos, there was no correlation between type of culture mode and the clinical outcome among cases received different transfer cycles (OR=1.339; 95% CI: 0.842-2.128; p =0.217). Table 2 Basic information and embryo transfer outcome for the 320 retrieved cycles Index DC mode HC mode t or x 2 p value Cycle 184 136 Female age 31.1 ± 3.8 31.5 ± 4.1 0.94 0.348 Male age 33.3 ± 5.1 33.7 ± 5.4 0.756 0.450 Infertility time, year 3.5 ± 2.5 3.4 ± 2.4 0.487 0.626 Primary infertility or secondary infertility 93/91 70/66 0.027 0.910 BMI 21.2 ± 2.6 21.7 ± 2.7 1.606 0.109 Cause of infertility 0.258 Factors from the female 92 73 Factors from the male 30 21 4.03 Factors from the couples 49 26 Unknown 13 16 Ovarian stimulation regime Long protocol 32 40 Antagonist protocol 95 58 7.462 0.059 Minimal stimulation protocol 37 21 Others 20 17 No. of oocytes retrieval 9.6 ± 6.3 10.3 ± 7.2 0.851 0.396 IVF/ICSI 128/56 107/29 3.328 0.074 High-quality embryo rate, % 58.2 53.0 5.57 0.018 Endometrial preparation protocol Natural cycle 82 57 Hormone replacement therapy 95 74 0.245 0.885 Ovarian stimulation protocol 7 5 No. of embryo transfer 1.73 ± 0.44 1.87 ± 0.34 2.942 0.004 Clinical pregnancy rate, % 64.7 58.1 1.438 0.246 Implantation rate, % 49.8 40.6 4.42 0.027 Abortion rate, % 13.4 12.7 0.026 1.000 Liver birth rate, % 54.3 50.0 0.593 0.497 Comparison of the offspring In this section, we compared the offspring from the couples underwent DC and HC. There were no statistical differences in the gestational weeks (35.9±2.2 weeks vs. 36.3±1.6 weeks, p >0.05) and rate of preterm birth (57.5% vs. 45.0%, p >0.05) of the women with Singleton or twin pregnancy between the two groups ( p >0.05). In addition, the body weight and malformation rate also showed no statistical differences ( p >0.05, Table 3 ). Table 3 Offspring conditions obtained from dry culture and humid culture Index DC mode HC mode t or x 2 p value Singleton pregnancy 68 49 Gestational age, w 38.7 ± 1.4 39.1 ± 1.4 1.333 0.185 Preterm birth rate, % 10.3 6.1 0.634 0.517 Body weight, g 3251 ± 498 3328 ± 439 0.862 0.391 Low birth weight rate, % 5.9 6.1 0.003 1.000 Anomaly rate, % 0 0 Twin pregnancy 32 19 Gestational age, w 35.9 ± 2.2 36.3 ± 1.6 0.799 0.428 Preterm birth rate, % 59.4 42.1 1.427 0.261 Body weight, g 2428 ± 746 2534 ± 451 0.791 0.431 Low birth weight rate, % 51.6 44.7 0.445 0.544 Anomaly rate, % 1.6 2.6 0.142 1.000 Discussion This study was divided into two sections. In the first section, we determined the fertilization rate, cleavage rate and high-quality embryo rate of the 525 oocytes from 21 cycles in the DC group (N=262) and HC group (N=263). In the second section, we determined the embryo transfer outcome and the offspring outcome from the 320 oocyte retrieval cycles in DC group (N=184) and HC group (N=136). Our data showed that there were no statistical differences in the fertilization rate and cleavage rate between the DC group and HC group. However, the rate of high-quality embryo in the DC group was significantly higher than that of the HC group. Our data showed that the embryo obtained from DC presented a higher implantation rate. Additionally, the physiological indices of the offspring delivered based on DC were similar with those based on the HC. Thus, we speculated that DC showed superiority and comparable safety in the IVF-ET compared with that of the HC. Currently, the TLI system frequently utilized for the assisted reproductive therapy is mainly based on DC, in order to obtain high-quality embryo. In a previous study, the proportion of high-grade embryos on day 2 was significantly higher in the TLI group compared with the G185 group (40.4% vs. 35.2%), while the proportion on day 2 in the TLI group was higher than that of the 8-cell stage (34.3% vs. 25.3%) [12]. In addition, Sciorio et al indicated that the proportion of high quality embryos was higher in the Embryoscope time-lapse incubator group compared to the benchtop incubator on day 3 (75.1 vs. 56.0%, p = 0.006) [13]. In a previous study, based on the in vitro culture of 571 oocytes, Elqusi et al reported that the rate of blastocyst obtained in the DC model was significantly higher than that in the HC model (62.9% vs. 43.5%) [8]. It implied that the DC may serve as a promising culture model for embryo for the IVF-ET. Indeed, some studies indicated that HC was superior to the DC in the IVF-ET. For example, the DC mode was associated with quality decline in the embryo at the cleavage stage and a lower rate of blastocyst formation compared with the HC mode, resulting in a decreased implantation and ongoing pregnancy rates [7]. In addition, there was strong evidence that culture conditions with high humidity atmosphere promoted embryo development and reproductive outcome [14]. In the Cairo consensus guidelines on IVF culture conditions, the DC and HC contributed to satisfactory outcome in clinical settings, but the HC was proved to be more suitable for IVF-ET [3]. This is related to the fact that the humidity in the chamber can be modulated through the water evaporation in the humid incubator, which can attenuate the water loss in the culture. This avoids the potential damages to the embryonic development caused by elevation of osmotic pressure. Compared with the previous studies [7, 15], the major data differences in our study may be associated with the in vitro conditions. According to the previous description, the zygotes were cultured until day 5 and day 6 without replacing the culture solution. In this process, a long-time culture may lead to loss of water content, which subsequently induced elevation in the osmotic pressure of the embryo [16]. Six droplets (100 μl) were placed in 35 mm Petri dish, and 3.5 ml mineral oil was overlaid. After 2 days of DC, the osmotic pressure showed a merely elevation of 1.8mOsm [17]. The osmotic changes in the DC condition were about 20 mOsm after 6 days of incubation [15]. This implied that the osmotic pressure of the micro-droplets in the DC system would remarkably increase with the time. In this study, the persistent utilization of droplets for three days could avoid the potential damages to the embryo induced by the osmotic pressure changes. In fact, the slight change of osmotic pressure during the embryo culture could be effectively corrected by the glycine in the culture medium [18] and the intracellular glycine [19]. In vitro, under conditions of increased osmolarity, 50 mM glycine can be accumulated in 1-cell mice embryos, which could balance up to about 50 mOsm of external osmotic pressure [20]. Furthermore, increasing the oil volume for the coverage of micro-droplets may affect the efficiency of DC. For instance, Swain et al [15] indicated that the elevation of the oil volume may reduce the water loss and decrease the alternation of the osmotic pressure. In this study, we did not hold a deep investigation on the osmotic pressure changes after knowing the conclusion from Mori et al [17]. In addition, we did not investigate the optimal volume of the oil for the embryo culture; however, a volume of 8.5 ml was effective for the embryo culture. Therefore, appropriate culture method should be adopted for the DC in order to effective control the potential risks induced by changes of osmotic pressure. Indeed, there are some limitations in our study. For instance, the sample size is not large, lack of multi-centered data. In future, we will focus on data collection of the clinical treatment cycle performed in multiple centers, in order to obtain more representative data. Conclusions In summary, DC serving as a novel type for the embryo culture showed a higher high-quality embryo rate compared with the HC. Besides, DC was associated with a higher implantation rate after embryo transfer. There were no statistical differences in the offspring conditions between the DC and HC. Taken together, the DC is a promising method for the embryo culture of IVF-ET. Abbreviations in vitro fertilization-embryo transfer (IVF-ET); dry culture (DC); humid culture (HC); Time-Lapse Imagine (TLI); frozen-thawed embryo transfer (FET); intracytoplasmic sperm injection (ICSI); follicle-stimulating hormone (FSH); human menopause gonadotropin (HMG). Declarations Checklist Statement The study is reported in accordance with STROBE guidelines. Ethics approval and consent to participate This study was approved by the Reproductive Ethics Committee of Zhejiang Provincial People's Hospital (Protocol # SZ2016013). Written informed consent was obtained from each patient. Consent for publication Not applicable. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding Not applicable. Authors’ contributions XWH wrote the manuscript; SJ revised the manuscript; LSS and ZL did the data analysis; ZL did the data collection. All authors reviewed the manuscript. Acknowledgements Not applicable. References 1. Yumoto K, Iwata K, Sugishima M, Yamauchi J, Nakaoka M, Tsuneto M, et al. Unstable osmolality of microdrops cultured in non-humidified incubators. J Assist Reprod Genet. 2019;36:1571-7. 2. Albert C, Gonzalez N, Marcos J, Alegre L, Ruiz BA, De Los Santos JM, et al. The effect of high humidity culture conditions over embryo development: a continuous embryo monitoring assessment. Reproductive Biomedicine Online. 2018;37:e15–e6. 3. Consensus Group C. 'There is only one thing that is truly important in an IVF laboratory: everything' Cairo Consensus Guidelines on IVF Culture Conditions. Reprod Biomed Online. 2020;40:33-60. 4. Geraghty RJ, Capes-Davis A, Davis JM, Downward J, Freshney RI, Knezevic I, et al. Guidelines for the use of cell lines in biomedical research. Br J Cancer. 2014;111:1021-46. 5. Baltz JM. Media composition: salts and osmolality. Methods Mol Biol. 2012;912:61-80. 6. McKiernan SH, Bavister BD. Environmental variables influencing in vitro development of hamster 2-cell embryos to the blastocyst stage. Biol Reprod. 1990;43:404-13. 7. Fawzy M, AbdelRahman MY, Zidan MH, Abdel Hafez FF, Abdelghafar H, Al-Inany H, et al. Humid versus dry incubator: a prospective, randomized, controlled trial. Fertil Steril. 2017;108:277-83. 8. Elqusi KM, Hussin AA, Alkhader HA, Zaki H. Humid versus dry bench-top incubator: a case control study. Fertility and Sterility. 2018;110:e356. 9. Orvieto R, Nahum R, Zohav E, Liberty G, Anteby EY, Meltcer S. GnRH-agonist ovulation trigger in patients undergoing controlled ovarian hyperstimulation for IVF with ultrashort flare GnRH-agonist combined with multidose GnRH-antagonist protocol. Gynecol Endocrinol. 2013;29:51-3. 10. Rinaldi L, Lisi F, Selman H. Mild/minimal stimulation protocol for ovarian stimulation of patients at high risk of developing ovarian hyperstimulation syndrome. J Endocrinol Invest. 2014;37:65-70. 11. The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting. Hum Reprod. 2011;26:1270-83. 12. Barberet J, Chammas J, Bruno C, Valot E, Vuillemin C, Jonval L, et al. Randomized controlled trial comparing embryo culture in two incubator systems: G185 K-System versus EmbryoScope. Fertil Steril. 2018;109:302-9.e1. 13. Sciorio R, Thong JK, Pickering SJ. Comparison of the development of human embryos cultured in either an EmbryoScope or benchtop incubator. J Assist Reprod Genet. 2018;35:515-22. 14. Albert C, Gonzalez N, Marcos J, Alegre L, Ruiz BA, De Los Santos JM, et al. P-028-The effect of high humidity culture conditions over embryo development: a continuous embryo monitoring assessment. Reproductive BioMedicine Online. 2018;37:e15-e6. 15. Swain JE, Graham C, Kile R, Schoolcraft WB, Krisher RL. Media evaporation in a dry culture incubator; effect of dish, drop size and oil on media osmolality. Fertility and Sterility. 2018;110:e363-e4. 16. Boumerdassi Y, Huet S, Millin M, Sarandi S, Bennani Smires B, Sifer C. [Impact of the type of incubator (non-humidified versus humidified) on embryo culture media osmolality]. Gynecol Obstet Fertil Senol. 2020:S2468-7189(20)30351-2. 17. Mori C, Kuwayama M, Silber SJ, Kagawa N, Takehara Y, Kato O. Water evaporation and osmolarity change of human embryo culture media in humid or in dry culture systems. Fertility & Sterility. 2010;94:S151-S. 18. Van Winkle LJ, Haghighat N, Campione AL. Glycine protects preimplantation mouse conceptuses from a detrimental effect on development of the inorganic ions in oviductal fluid. J Exp Zool. 1990;253:215-9. 19. Tartia AP, Rudraraju N, Richards T, Hammer MA, Talbot P, Baltz JM. Cell volume regulation is initiated in mouse oocytes after ovulation. Development. 2009;136:2247-54. 20. Baltz JM, Tartia AP. Cell volume regulation in oocytes and early embryos: connecting physiology to successful culture media. Hum Reprod Update. 2010;16:166-76. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 2 posted You are reading this latest preprint version Show more versions 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-335124","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":36124407,"identity":"ef4eb155-4129-472d-a55c-fe33c92b7f23","order_by":0,"name":"Weihai Xu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0klEQVRIiWNgGAWjYLCCxAYGHn4JMJOZBC2SM0jSwtjAwGBwg1gtBjdyDB883GEnY3y7O/EDQ4V1YgP72QN4tUjOyDE2SDyTzGN25+xmCYYz6YkNPHkJeLXwS+Ruk0hsY+Yxu5G7jYGx7XBigwSPAV4tbBK5238kttXzGM8AaflHhBaQLQyJbYd5DEAMxgYitEj2vP8MdNhxHokbuZslEo6lG7fx5ODXYnA8LfHjz7Zqe/4ZuRs/fKixlu1nP4NfCypIAPmOBPWjYBSMglEwCnAAALusQsh5AED+AAAAAElFTkSuQmCC","orcid":"","institution":"Department of Reproductive Endocrinology, Zhejiang Provincial People’s Hospital, Hangzhou Medical College","correspondingAuthor":true,"prefix":"","firstName":"Weihai","middleName":"","lastName":"Xu","suffix":""},{"id":36124408,"identity":"fbb4d357-2128-461f-944a-32a5a5482c83","order_by":1,"name":"Lin Zhang","email":"","orcid":"","institution":"Department of Reproductive Endocrinology, Zhejiang Provincial People’s Hospital, Hangzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Lin","middleName":"","lastName":"Zhang","suffix":""},{"id":36124409,"identity":"c12c200f-17cf-4089-aea7-8c29e4079496","order_by":2,"name":"Ling Zhang","email":"","orcid":"","institution":"Department of Reproductive Endocrinology, Zhejiang Provincial People’s Hospital, Hangzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Ling","middleName":"","lastName":"Zhang","suffix":""},{"id":36124410,"identity":"84e1da79-893a-4509-ba9a-01967e991bc6","order_by":3,"name":"Shishi Li","email":"","orcid":"","institution":"Department of Reproductive Endocrinology, Zhejiang Provincial People’s Hospital, Hangzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Shishi","middleName":"","lastName":"Li","suffix":""},{"id":36124411,"identity":"b250c06e-8248-4100-97de-458bdc534ba1","order_by":4,"name":"Jing Shu","email":"","orcid":"","institution":"Department of Reproductive Endocrinology, Zhejiang Provincial People’s Hospital, Hangzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Shu","suffix":""}],"badges":[],"createdAt":"2021-03-17 02:30:09","currentVersionCode":2,"declarations":"","doi":"10.21203/rs.3.rs-335124/v2","doiUrl":"https://doi.org/10.21203/rs.3.rs-335124/v2","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":14934233,"identity":"8614eccb-3b67-4902-82b4-efab2dd49100","added_by":"auto","created_at":"2021-10-27 08:14:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":323503,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-335124/v2/38853949-eee3-47b8-9ab8-b09da23208fc.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eEfficiency Comparison Between Dry And Humid Cultures For Clinical Outcome of The In Vitro Fertilization-Embryo Transfer\u003c/p\u003e","fulltext":[{"header":"Background","content":" \u003cp\u003eIn vitro fertilization-embryo transfer (IVF-ET) is considered a promising treatment option for the infertile couples. Its core element is to achieve IVF and select embryos with developmental potency for the transfer and/or cryopreservation. For a long time, humid culture (HC) has been conventionally utilized for the in vitro embryo culture. It provides a saturated humidity in the culture environment for embryo by means of water vaporization in an active manner or humidification based on disposable humidification flask. On this basis, the osmotic pressure of culture medium is stable [1, 2], contributing to the culture of zygote and embryo. Therefore, it is recommended as the major method for embryo culture [3].\u003c/p\u003e \u003cp\u003eAs a new technique, dry culture (DC) has been used in the human embryo culture. Unlike the HC inducing generation of microorganisms that may affect the embryonic growth, DC involving a relatively dry environment can reduce the risks of microorganism growth [4]. In addition, by integrating with the Time-Lapse Imagine (TLI) technique, DC promotes the comprehensive monitoring of the embryonic growth.\u003c/p\u003e \u003cp\u003eTo date, few studies have been carried out to investigate the efficiency of DC in clinical settings [5, 6]. In a previous study, Fawzy et al indicated that the developed high-quality embryo rate on day 3 was significantly lower in the DC group than in the HC group (65% vs. 83%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) [7]. In contrast, Elqusi et al reported that the high-quality blastocyst rate in the DC group was significantly higher than that of the HC group (62.9% vs. 43.5%) [8]. Furthermore, little is known about the effects of DC on the outcome of embryo transfer and offspring. In this study, we compared the effects of DC and HC on the offspring and evaluated the feasibility of the IVF-ET on the DC and HC.\u003c/p\u003e "},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Reproductive Ethics Committee of Zhejiang Provincial People\u0026apos;s Hospital (Protocol # SZ2016013). Written informed consent was obtained from each patient.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDevices\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe EC6-230LE dry incubator (Astec, Japan) and APM-50 D humid incubator (Astec, Japan) were used in this study. The temperature, CO\u003csub\u003e2\u003c/sub\u003e and O\u003csub\u003e2\u003c/sub\u003e concentration were determined per day before the experiments.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSubjects\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe IVF-ET related data were collected from 501 subjects presenting to the Reproductive Medicine Center, Zhejiang Provincial People\u0026rsquo;s Hospital between November 2016 and October 2017. The inclusion criteria were as follows: (i) female aged \u0026le;38 yrs; (ii) those received frozen-thawed embryo transfer (FET) as the first embryo transfer; (iii) those received transfer of D3 high-quality embryos. Those with the following conditions were excluded from this study: (i) any individual of the couples presenting chromosomal anomaly; (ii) those with rescue intracytoplasmic sperm injection (ICSI) cycles after the IVF.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExperimental design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwenty-one cycles with oocytes retrieval of \u0026ge;20 was collected in this study. The oocytes in each cycle were randomly divided into DC group (N=262 oocytes) and HC group (N=263 oocytes). Then we determined the in vitro culture efficiency including the fertilization rate, cleavage rate and high-quality embryo rate. In order to eliminate the effects of other factors on the clinical outcome, we analyzed the clinical outcome of the embryo and offspring conditions based on different culture model. Eventually, 352 cycles met the inclusion criteria, and 320 cycles were finally included in this study, consisting of DC group (N=184) and HC group (N=136), after excluding 5 with female chromosome abnormality, 5 with male chromosome abnormality, and 22 with rescue ICSI.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIVF therapy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe oocytes retrieval, IVF and embryo culture were conducted in our lab using the GnRH antagonist protocol, long protocol, and minimal stimulation protocol according to the previous description [9, 10]. The follicle-stimulating hormone (FSH), human menopause gonadotropin (HMG) and clomiphene were utilized to stimulate the follicular development according to the ovary reserve and response. In cases of a diameter of \u0026gt;17 mm in two follicles, or a diameter of \u0026gt;18 mm in one follicle, human chorionic gonadotrophin (HCG) and/or GnRH-a were administrated, followed by oocytes retrieval within 36-38 hrs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn order to avoid the influences of repetitive door open during the culture procedure, the chamber was performed independently for the in vitro culture cycle. The COOK sequential media (Cook Medical, Brisbane, Australia) was utilized for the IVF and embryo culture. The droplets prepared based on fertilization medium (FM, 80\u0026micro;l) and cleavage medium (CM, 30\u0026micro;l) were transferred to petri dishes (60\u0026times;15, 353652, Falcon), followed by covering with 8.5 ml embryo culture oil (ART-4008-5P, Origio). Upon oocytes retrieval, conventional IVF or ICSI was performed. On day 3, the high-quality embryo was selected according to the ASBIR criteria [11] for the subsequent embryo cryopreservation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe endometrial preparation protocol of the FET cycle consists of natural cycle, hormone replacement therapy protocol and ovarian stimulation protocol. Based on the endometrium development conditions, one or two D3 high-quality frozen embryo was thawed, followed by transfer. Then the serum HCG was measured on day 12 to determine whether the female was pregnant. The clinical pregnancy was defined as presence of gestational sac by B-ultrasonography on day 35 after transfer. Those presenting no fetal heart or loss of fetal heart at week 12 were defined as early abortion. Ongoing pregnancy was defined as development of gestational sac for at least 12 weeks.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSPSS 19.0 software was used for the data analysis. Measurement data that were normally distributed were presented as mean \u0026plusmn; standard deviation. Inter-group comparison was conducted using Student\u0026rsquo;s t-test. The comparison of numeration data was conducted using the Chi square test. Multi-variate logistic regression analysis was used to analyze the effects of female age, fertilization protocol, number of transferred embryos, and the culture mode on the pregnancy. \u003cem\u003ep\u003c/em\u003e\u0026lt;0.05 was statistically significant.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eComparison of fertilization rate, cleavage rate and high-quality embryo rate in sibling oocyte\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe fertilization rate in the DC group showed10 no statistical difference compared with the HC group (69.8% vs. 68.8%, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05, \u003cstrong\u003eTable\u003c/strong\u003e \u003cstrong\u003e1\u003c/strong\u003e). Meanwhile, there were no differences in the rate of cleavage between the two groups (98.4% vs. 98.9%, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). The high-quality embryo rate in the DC group was significantly higher than that of the HC group (66.1% vs. 55.3%, \u003cem\u003ep\u003c/em\u003e=0.036).\u0026nbsp;\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eIn vitro culture results for the 21 IVF cycles\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIndex\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDC mode\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eHC mode\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003et or x\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOocyte number\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e262\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e263\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFertility rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e69.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e68.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.065\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.799\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCleavage rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.176\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.675\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHigh-quality embryo rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e66.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e55.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.392\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.036\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003eClinical outcome for the embryo transfer\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCompared with the DC group, there were no statistical differences in the age of the couple, infertility duration, previous history of pregnancy, causes of infertility, BMI, ovarian stimulation protocol, fertilization protocol and endometrial preparation protocol in the HC group (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05, \u003cstrong\u003eTable\u003c/strong\u003e \u003cstrong\u003e2\u003c/strong\u003e). The number of transferred embryo in the DC group was significantly lower than that of the HC group (1.73\u0026plusmn;0.44 vs. 1.87\u0026plusmn;0.34, \u003cem\u003ep\u003c/em\u003e=0.004). The implantation rate of embryo in the DC group was significantly higher than that of the HC group (49.8% vs. 40.6%, \u003cem\u003ep\u003c/em\u003e=0.027). After adjusting the female age, endometrial preparation protocol, fertilization protocol and number of transferred embryos, there was no correlation between type of culture mode and the clinical outcome among cases received different transfer cycles (OR=1.339; 95% CI: 0.842-2.128; \u003cem\u003ep\u003c/em\u003e=0.217). \u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" id=\"Tab2\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eBasic information and embryo transfer outcome for the 320 retrieved cycles\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIndex\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDC mode\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eHC mode\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003et or x\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e136\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemale age\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.348\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale age\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.756\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.450\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eInfertility time, year\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.487\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.626\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePrimary infertility or secondary infertility\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e93/91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e70/66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.027\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.910\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.606\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.109\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCause of infertility\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\" rowspan=\"5\"\u003e\n \u003cp\u003e0.258\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFactors from the female\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFactors from the male\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.03\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFactors from the couples\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUnknown\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOvarian stimulation regime\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLong protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAntagonist protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.462\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.059\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMinimal stimulation protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNo. of oocytes retrieval\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.6\u0026thinsp;\u0026plusmn;\u0026thinsp;6.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10.3\u0026thinsp;\u0026plusmn;\u0026thinsp;7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.851\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.396\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIVF/ICSI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e128/56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e107/29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.328\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.074\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHigh-quality embryo rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e58.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e53.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.018\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEndometrial preparation protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNatural cycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHormone replacement therapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.245\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.885\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOvarian stimulation protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNo. of embryo transfer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.942\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eClinical pregnancy rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e64.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e58.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.438\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.246\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eImplantation rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e49.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.027\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAbortion rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.026\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLiver birth rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e54.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e50.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.593\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.497\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison of the offspring\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this section, we compared the offspring from the couples underwent DC and HC. There were no statistical differences in the gestational weeks (35.9\u0026plusmn;2.2 weeks vs. 36.3\u0026plusmn;1.6 weeks, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) and rate of preterm birth (57.5% vs. 45.0%, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) of the women with Singleton or twin pregnancy between the two groups (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). In addition, the body weight and malformation rate also showed no statistical differences (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05, \u003cstrong\u003eTable\u003c/strong\u003e\u003cstrong\u003e3\u003c/strong\u003e). \u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" id=\"Tab3\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eOffspring conditions obtained from dry culture and humid culture\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIndex\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDC mode\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eHC mode\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003et or x\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSingleton pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGestational age, w\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.333\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.185\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePreterm birth rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.634\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.517\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBody weight, g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3251\u0026thinsp;\u0026plusmn;\u0026thinsp;498\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3328\u0026thinsp;\u0026plusmn;\u0026thinsp;439\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.862\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.391\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLow birth weight rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAnomaly rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTwin pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGestational age, w\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.799\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.428\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePreterm birth rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e59.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.427\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.261\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBody weight, g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2428\u0026thinsp;\u0026plusmn;\u0026thinsp;746\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2534\u0026thinsp;\u0026plusmn;\u0026thinsp;451\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.791\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.431\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLow birth weight rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e51.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e44.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.445\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.544\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAnomaly rate, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.142\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n"},{"header":"Discussion","content":"\u003cp\u003eThis study was divided into two sections. In the first section, we determined the fertilization rate, cleavage rate and high-quality embryo rate of the 525 oocytes from 21 cycles in the DC group (N=262) and HC group (N=263). In the second section, we determined the embryo transfer outcome and the offspring outcome from the 320 oocyte retrieval cycles in DC group (N=184) and HC group (N=136). Our data showed that there were no statistical differences in the fertilization rate and cleavage rate between the DC group and HC group. However, the rate of high-quality embryo in the DC group was significantly higher than that of the HC group. Our data showed that the embryo obtained from DC presented a higher implantation rate. Additionally, the physiological indices of the offspring delivered based on DC were similar with those based on the HC. Thus, we speculated that DC showed superiority and comparable safety in the IVF-ET compared with that of the HC.\u003c/p\u003e\n\u003cp\u003eCurrently, the TLI system frequently utilized for the assisted reproductive therapy is mainly based on DC, in order to obtain high-quality embryo. In a previous study, the proportion of high-grade embryos on day 2 was significantly higher in the TLI group compared with the G185 group (40.4% vs. 35.2%), while the proportion on day 2 in the TLI group was higher than that of the 8-cell stage (34.3% vs. 25.3%) [12]. In addition, Sciorio et al indicated that the proportion of high quality embryos was higher in the Embryoscope time-lapse incubator group compared to the benchtop incubator on day 3 (75.1 vs. 56.0%, \u003cem\u003ep\u003c/em\u003e=\u0026thinsp;0.006) [13]. In a previous study, based on the in vitro culture of 571 oocytes, Elqusi et al reported that the rate of blastocyst obtained in the DC model was significantly higher than that in the HC model (62.9% vs. 43.5%) [8]. It implied that the DC may serve as a promising culture model for embryo for the IVF-ET.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIndeed, some studies indicated that HC was superior to the DC in the IVF-ET. For example, the DC mode was associated with quality decline in the embryo at the cleavage stage and a lower rate of blastocyst formation compared with the HC mode, resulting in a decreased implantation and ongoing pregnancy rates [7]. In addition, there was strong evidence that culture conditions with high humidity atmosphere promoted embryo development and reproductive outcome [14]. In the Cairo consensus guidelines on IVF culture conditions, the DC and HC contributed to satisfactory outcome in clinical settings, but the HC was proved to be more suitable for IVF-ET [3]. This is related to the fact that the humidity in the chamber can be modulated through the water evaporation in the humid incubator, which can attenuate the water loss in the culture. This avoids the potential damages to the embryonic development caused by elevation of osmotic pressure.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCompared with the previous studies [7, 15], the major data differences in our study may be associated with the in vitro conditions. According to the previous description, the zygotes were cultured until day 5 and day 6 without replacing the culture solution. In this process, a long-time culture may lead to loss of water content, which subsequently induced elevation in the osmotic pressure of the embryo [16]. Six droplets (100 \u0026mu;l) were placed in 35 mm Petri dish, and 3.5 ml mineral oil was overlaid. After 2 days of DC, the osmotic pressure showed a merely elevation of 1.8mOsm [17]. The osmotic changes in the DC condition were about 20 mOsm after 6 days of incubation [15]. This implied that the osmotic pressure of the micro-droplets in the DC system would remarkably increase with the time. In this study, the persistent utilization of droplets for three days could avoid the potential damages to the embryo induced by the osmotic pressure changes. In fact, the slight change of osmotic pressure during the embryo culture could be effectively corrected by the glycine in the culture medium [18] and the intracellular glycine [19]. In vitro, under conditions of increased osmolarity, 50 mM glycine can be accumulated in 1-cell mice embryos, which could balance up to about 50 mOsm of external osmotic pressure [20]. Furthermore, increasing the oil volume for the coverage of micro-droplets may affect the efficiency of DC. For instance, Swain et al [15] indicated that the elevation of the oil volume may reduce the water loss and decrease the alternation of the osmotic pressure. In this study, we did not hold a deep investigation on the osmotic pressure changes after knowing the conclusion from Mori et al [17]. In addition, we did not investigate the optimal volume of the oil for the embryo culture; however, a volume of 8.5 ml was effective for the embryo culture. Therefore, appropriate culture method should be adopted for the DC in order to effective control the potential risks induced by changes of osmotic pressure.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIndeed, there are some limitations in our study. For instance, the sample size is not large, lack of multi-centered data. In future, we will focus on data collection of the clinical treatment cycle performed in multiple centers, in order to obtain more representative data.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn summary, DC serving as a novel type for the embryo culture showed a higher high-quality embryo rate compared with the HC. Besides, DC was associated with a higher implantation rate after embryo transfer. There were no statistical differences in the offspring conditions between the DC and HC. Taken together, the DC is a promising method for the embryo culture of IVF-ET.\u0026nbsp;\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003ein vitro fertilization-embryo transfer (IVF-ET); dry culture (DC); humid culture (HC); Time-Lapse Imagine (TLI); frozen-thawed embryo transfer (FET); intracytoplasmic sperm injection (ICSI); follicle-stimulating hormone (FSH); human menopause gonadotropin (HMG).\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eChecklist Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study is reported in accordance with STROBE guidelines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Reproductive Ethics Committee of Zhejiang Provincial People\u0026apos;s Hospital (Protocol # SZ2016013). Written informed consent was obtained from each patient.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXWH\u0026nbsp;wrote the manuscript; SJ revised the manuscript; LSS and ZL did the data analysis; ZL did the data collection.\u0026nbsp;All authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003cp\u003e1. Yumoto K, Iwata K, Sugishima M, Yamauchi J, Nakaoka M, Tsuneto M, et al. Unstable osmolality of microdrops cultured in non-humidified incubators. J Assist Reprod Genet. 2019;36:1571-7.\u003c/p\u003e\n\u003cp\u003e2. Albert C, Gonzalez N, Marcos J, Alegre L, Ruiz BA, De Los Santos JM, et al. The effect of high humidity culture conditions over embryo development: a continuous embryo monitoring assessment. Reproductive Biomedicine Online. 2018;37:e15\u0026ndash;e6.\u003c/p\u003e\n\u003cp\u003e3. Consensus Group C. \u0026apos;There is only one thing that is truly important in an IVF laboratory: everything\u0026apos; Cairo Consensus Guidelines on IVF Culture Conditions. Reprod Biomed Online. 2020;40:33-60.\u003c/p\u003e\n\u003cp\u003e4. Geraghty RJ, Capes-Davis A, Davis JM, Downward J, Freshney RI, Knezevic I, et al. Guidelines for the use of cell lines in biomedical research. Br J Cancer. 2014;111:1021-46.\u003c/p\u003e\n\u003cp\u003e5. Baltz JM. Media composition: salts and osmolality. Methods Mol Biol. 2012;912:61-80.\u003c/p\u003e\n\u003cp\u003e6. McKiernan SH, Bavister BD. Environmental variables influencing in vitro development of hamster 2-cell embryos to the blastocyst stage. Biol Reprod. 1990;43:404-13.\u003c/p\u003e\n\u003cp\u003e7. Fawzy M, AbdelRahman MY, Zidan MH, Abdel Hafez FF, Abdelghafar H, Al-Inany H, et al. Humid versus dry incubator: a\u0026nbsp;prospective, randomized, controlled trial. Fertil Steril. 2017;108:277-83.\u003c/p\u003e\n\u003cp\u003e8. Elqusi KM, Hussin AA, Alkhader HA, Zaki H. Humid versus dry bench-top incubator: a case control study. Fertility and Sterility. 2018;110:e356.\u003c/p\u003e\n\u003cp\u003e9. Orvieto R, Nahum R, Zohav E, Liberty G, Anteby EY, Meltcer S. GnRH-agonist ovulation trigger in patients undergoing controlled ovarian hyperstimulation for IVF with ultrashort flare GnRH-agonist combined with multidose GnRH-antagonist protocol. Gynecol Endocrinol. 2013;29:51-3.\u003c/p\u003e\n\u003cp\u003e10. Rinaldi L, Lisi F, Selman H. Mild/minimal stimulation protocol for ovarian stimulation of patients at high risk of developing ovarian hyperstimulation syndrome. J Endocrinol Invest. 2014;37:65-70.\u003c/p\u003e\n\u003cp\u003e11. The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting. Hum Reprod. 2011;26:1270-83.\u003c/p\u003e\n\u003cp\u003e12. Barberet J, Chammas J, Bruno C, Valot E, Vuillemin C, Jonval L, et al. Randomized controlled trial comparing embryo culture in two incubator systems: G185 K-System versus EmbryoScope. Fertil Steril. 2018;109:302-9.e1.\u003c/p\u003e\n\u003cp\u003e13. Sciorio R, Thong JK, Pickering SJ. Comparison of the development of human embryos cultured in either an EmbryoScope or benchtop incubator. J Assist Reprod Genet. 2018;35:515-22.\u003c/p\u003e\n\u003cp\u003e14. Albert C, Gonzalez N, Marcos J, Alegre L, Ruiz BA, De Los Santos JM, et al. P-028-The effect of high humidity culture conditions over embryo development: a continuous embryo monitoring assessment. Reproductive BioMedicine Online. 2018;37:e15-e6.\u003c/p\u003e\n\u003cp\u003e15. Swain JE, Graham C, Kile R, Schoolcraft WB, Krisher RL. Media evaporation in a dry culture incubator; effect of dish, drop size and oil on media osmolality. Fertility and Sterility. 2018;110:e363-e4.\u003c/p\u003e\n\u003cp\u003e16. Boumerdassi Y, Huet S, Millin M, Sarandi S, Bennani Smires B, Sifer C. [Impact of the type of incubator (non-humidified versus humidified) on embryo culture media osmolality]. Gynecol Obstet Fertil Senol. 2020:S2468-7189(20)30351-2.\u003c/p\u003e\n\u003cp\u003e17. Mori C, Kuwayama M, Silber SJ, Kagawa N, Takehara Y, Kato O. Water evaporation and osmolarity change of human embryo culture media in humid or in dry culture systems. Fertility \u0026amp; Sterility. 2010;94:S151-S.\u003c/p\u003e\n\u003cp\u003e18. Van Winkle LJ, Haghighat N, Campione AL. Glycine protects preimplantation mouse conceptuses from a detrimental effect on development of the inorganic ions in oviductal fluid. J Exp Zool. 1990;253:215-9.\u003c/p\u003e\n\u003cp\u003e19. Tartia AP, Rudraraju N, Richards T, Hammer MA, Talbot P, Baltz JM. Cell volume regulation is initiated in mouse oocytes after ovulation. Development. 2009;136:2247-54.\u003c/p\u003e\n\u003cp\u003e20. \u0026nbsp; Baltz JM, Tartia AP. Cell volume regulation in oocytes and early embryos: connecting physiology to successful culture media. Hum Reprod Update. 2010;16:166-76.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Embryo, culture, In-vitro fertilization, embryo transfer, osmotic pressure","lastPublishedDoi":"10.21203/rs.3.rs-335124/v2","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-335124/v2","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e In this study, we compared the in vitro embryo development, embryo transfer outcome and the offspring outcome in the in vitro fertilization-embryo transfer (IVF-ET) between dry culture (DC) and humid culture (HC). \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e Our study was divided into two parts. Firstly, we determined the fertilization rate, cleavage rate and high-quality embryo rate from 21 cycles in the DC group (N=262 oocytes) and HC group (N=263 oocytes). Secondly, we determined the embryo transfer outcome and the offspring outcome in DC group (N=184 cycles) and HC group (N=136 cycles). \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Compared with the HC group, significant increase was observed in the high-quality embryo rate (66.1.2% vs. 55.3%, \u003cem\u003ep\u003c/em\u003e=0.037) and implantation rate (49.8% vs. 40.6%, \u003cem\u003ep\u003c/em\u003e=0.027) in the DC group. No statistical differences were observed in the pregnant outcome and birth defect of the offspring (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). Compared with HC, DC was associated with a higher high-quality embryo rate and a higher implantation rate after embryo transfer. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e No statistical differences were noticed in the offspring conditions between the two culture modes. Taken together, DC may serve as a promising method for IVF-ET.\u003c/p\u003e","manuscriptTitle":"Efficiency Comparison Between Dry And Humid Cultures For Clinical Outcome of The In Vitro Fertilization-Embryo Transfer","msid":"","msnumber":"","nonDraftVersions":[{"code":2,"date":"2021-06-29 19:46:09","doi":"10.21203/rs.3.rs-335124/v2","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}},{"code":1,"date":"2021-03-30 00:16:40","doi":"10.21203/rs.3.rs-335124/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9f7a9239-2ca0-4b35-ab3b-d5b4506821be","owner":[],"postedDate":"June 29th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":5344609,"name":"Maternal \u0026 Fetal Medicine"}],"tags":[],"updatedAt":"2021-10-27T08:14:07+00:00","versionOfRecord":[],"versionCreatedAt":"2021-06-29 19:46:09","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v2","identity":"rs-335124","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-335124","identity":"rs-335124","version":["v2"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}