Who is the manufacturer of Cryotop Vitrification Kit and Cryotop Thawing Kit?

Kitazato Biopharma Co., Ltd. filed the 510(k) submission for Cryotop Vitrification Kit and Cryotop Thawing Kit (K160864).

What is the FDA product code for Cryotop Vitrification Kit and Cryotop Thawing Kit?

MQL. It is classified under 21 CFR 884.6180 as a Class 2 device in the Obstetrics/Gynecology panel.

What is the regulatory pathway for Cryotop Vitrification Kit and Cryotop Thawing Kit?

510(k) clearance (submission type: Traditional).

Who can help prepare an FDA 510(k) submission like Cryotop Vitrification Kit and Cryotop Thawing Kit?

Innolitics — a medical-device software consultancy — provides regulatory and engineering support for FDA 510(k) submissions. See https://innolitics.com/services/510ks/ or contact https://innolitics.com/contact.

Cryotop Vitrification Kit and Cryotop Thawing Kit

K160864 · Kitazato Biopharma Co., Ltd. · MQL · Oct 7, 2016 · Obstetrics/Gynecology

Device Facts

Record ID	K160864
Device Name	Cryotop Vitrification Kit and Cryotop Thawing Kit
Applicant	Kitazato Biopharma Co., Ltd.
Product Code	MQL · Obstetrics/Gynecology
Decision Date	Oct 7, 2016
Decision	SESE
Submission Type	Traditional
Regulation	21 CFR 884.6180
Device Class	Class 2

Intended Use

The Cryotop® Vitrification Kit is indicated for use in the preparation, vitrification and storage of pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. The Cryotop® Thawing Kit is indicated for use in the preparation and thawing of vitrified pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos.

Device Story

Cryotop Vitrification and Thawing Kits are media sets for cryopreservation of embryos; used in ART clinics by embryologists. Vitrification process: embryos exposed to Equilibration Solution (ES) then Vitrification Solution (VS) containing ethylene glycol and DMSO; cryoprotectants replace water; embryos stored in liquid nitrogen. Thawing process: stepwise removal of cryoprotectants using Thawing Solution (TS), Dilution Solution (DS), and Wash Solution (WS). Kits include storage devices (Cryotop SC/US), Repro Plates, and dishes. Media contain Gentamicin. Output is a preserved embryo ready for future transfer. Benefits include successful embryo survival and clinical pregnancy rates comparable to fresh embryo transfers.

Clinical Evidence

Clinical evidence provided via literature review of three studies using Cryotop vitrification/thawing media. Studies reported clinical pregnancy rates ranging from 42% to 59% and ongoing/live birth rates from 30% to 48%. Results demonstrate survival rates consistent with standard ART procedures and comparable outcomes to fresh embryo transfers.

Technological Characteristics

Media components: Medium 199 (HEPES buffered), ethylene glycol, DMSO, trehalose, hydroxypropyl cellulose (HPC), and Gentamicin. Solutions are aseptically filtered; storage devices sterilized by radiation. Shelf life: 6 months. Storage: 2–8°C.

Indications for Use

Indicated for use in the preparation, vitrification, storage, and thawing of pronuclear (PN) zygotes, day 3 cleavage stage embryos, and blastocyst stage embryos for patients undergoing Assisted Reproductive Technology (ART) procedures.

Regulatory Classification

Identification

Reproductive media and supplement are products that are used for assisted reproduction procedures. Media include liquid and powder versions of various substances that come in direct physical contact with human gametes or embryos (including water, acid solutions used to treat gametes or embryos, rinsing solutions, sperm separation media, supplements, or oil used to cover the media) for the purposes of preparation, maintenance, transfer or storage. Supplements are specific reagents added to media to enhance specific properties of the media (e.g., proteins, sera, antibiotics, etc.).

Special Controls

*Classification.* Class II (special controls) (mouse embryo assay information, endotoxin testing, sterilization validation, design specifications, labeling requirements, biocompatibility testing, and clinical testing). The device, when it is phosphate-buffered saline used for washing, and short-term handling and manipulation of gametes and embryos; culture oil used as an overlay for culture media containing gametes and embryos; and water for assisted reproduction applications, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 884.9.

Predicate Devices

Vit Kit® - Vitrification Freeze Kit/ Vitrification Thaw Kit (K093273)

Related Devices

K171748 — Vitrification Kit and Thawing Kit · Kitazato Corporation · Dec 14, 2017
K242089 — Vitrification Freeze Kit (RFD-0101) Vitrification Thaw Kit (RFD-0201, RFD-0202) · Jiangsu Ruifuda Medical Device Co., Ltd. · Apr 10, 2025
K242561 — Dewin Reproductive Media (Dewin Vitrification Kit, Dewin Thawing Kit) · Donnevie Medical Technology (Shanghai) Co. , Ltd. · Apr 10, 2025
K233846 — Vitrification Solution Set and Warming Solution Set · Ecmpc, LLC · Aug 27, 2024
K223265 — CryoX Vitrification Freeze Kit / Thaw Kit · Zhejiang Horizon Medical Technology Co., Ltd. · May 11, 2023

Submission Summary (Full Text)

{0}------------------------------------------------ Image /page/0/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized image of an eagle with three heads, representing the department's mission to protect the health of all Americans and provide essential human services. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle image. The logo is black and white. Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002 October 7, 2016 KITAZATO BioPharma Co., Ltd. % Richard Vincins, CBA, CQA, RAC (US,EU) Vice President, QA/RA Emergo Global Consulting, LLC 816 Congress Avenue, Suite 1400 Austin, TX 78701 Re: K160864 Trade/Device Name: Cryotop® Vitrification Kit and Cryotop® Thawing Kit Regulation Number: 21 CFR§ 884.6180 Regulation Name: Reproductive Media and Supplements Regulatory Class: II Product Code: MOL. MOK Dated: September 2, 2016 Received: September 7, 2016 Dear Richard Vincins: We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading. If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. {1}------------------------------------------------ ### Page 2 - Richard Vincins, CBA, CQA, RAC (US,EU) You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050. If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance. You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Sincerely vours. # Joyce M. Whang -S for Benjamin R. Fisher, Ph.D. Director Division of Reproductive, Gastro-Renal, and Urological Devices Office of Device Evaluation Center for Devices and Radiological Health Enclosure {2}------------------------------------------------ ## Indications for Use 510(k) Number (if known) K160864 Device Name Cryotop® Vitrification Kit and Cryotop® Thawing Kit Indications for Use (Describe) The Cryotop® Vitrification Kit is indicated for use in the preparation, and storage of promuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. The Cryotop® Thawing Kit is indicated for use in the preparation and thawing of vitrified pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. Type of Use (Select one or both, as applicable) | Prescription Use (Part 21 CFR 801 Subpart D) | ☑ | |----------------------------------------------|---| | Over-The-Counter Use (21 CFR 801 Subpart C) | ☐ | #### CONTINUE ON A SEPARATE PAGE IF NEEDED. This section applies only to requirements of the Paperwork Reduction Act of 1995. #### *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: > Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." {3}------------------------------------------------ # 510(k) Summary ## Cryotop Vitrification and Thawing Kit ## K160864 #### 1. Submission Sponsor KITAZATO BioPharma Co., Ltd. 81 Nakajima, Fuji-city Shizuoka 416-0907 JAPAN Phone number: +(81) 546-66-2202 Contact: Futoshi Inoue Title: President #### 2. Submission Correspondent Emergo Global Consulting, LLC 2500 Bee Cave Road Building 1, Suite 300 Austin, TX 78746 Office Phone: (512) 327.9997 Contact: Richard A. Vincins, Vice President, QA/RA Email: project.management@emergogroup.com #### 3. Date Prepared 6 October 2016 {4}------------------------------------------------ #### 4. Device Identification | Trade/Proprietary Name: | Cryotop® Vitrification Kit Cryotop® Thawing Kit | |-------------------------|-----------------------------------------------------------------| | Common/Usual Name: | Vitrification Cryopreservation Media | | Classification Name: | Reproductive Media and Supplements | | Regulation Number: | 884.6180 | | Product Code: | MQL, Media, Reproductive MQK, Labware, Assisted Reproduction | | Device Class: | Class II | | Classification Panel: | Obstetrics/Gynecology | #### 5. Legally Marketed Predicate Device(s) K093273, Vit Kit® - Vitrification Freeze Kit/ Vitrification Thaw Kit, Irvine Scientific Sales Co., Inc. The predicate device has not been subject to a design-related recall. #### 6. Device Description The Cryotop® Vitrification and Thawing Kits are composed of a set of five media to vitrify and warm pronuclear (PN) through blastocyst stage embryos for Assisted Reproductive Technologies (ART) procedures. The Cryotop® Vitrification Kit includes two media components, Equilibration Solution (ES) and Vitrification Solution (VS), containing the cryoprotectants ethylene glycol and dimethyl sulfoxide. During the vitrification process, embryos are first exposed to ES and then in VS. Using this methodology, the permeating cryoprotectants can replace water in the PN through blastocyst stage embryos prior to vitrification and storage in liquid nitrogen. The Cryotop® Vitrification Kit comes pre-packaged with one 1.5 ml vial of ES, two 1.5 ml vials of VS, 4 Cryotop devices (Cryotop SC, or Cryotop US), and two Repro Plates. The Cryotop® Thawing Kit is composed of three media used stepwise for thawing and removing cryoprotectants from vitrified PN through blastocyst stage embryos. The Cryotop® Thawing Kit is composed of TS (Thawing Solution), DS (Dilution Solution) and WS (Wash Solution). The Cryotop Thawing Kit comes pre-packaged with two 4.0 ml vials of thawing solution, one 4.0 ml vial of dilution solution, one 4.0 ml vial of washing solution, one Repro Plate, and two 35 mm dishes. {5}------------------------------------------------ All of the media in the Cryotop® Vitrification Kit and Cryotop® Thawing Kit contain Gentamicin. The media in these kits undergo aseptic filtration, while storage devices are sterilized by radiation. The specifications for the Cryotop Vitrification and Thawing Kits are listed in Table 1 below. #### 7. Indication for Use Statement The Cryotop® Vitrification Kit is indicated for use in the preparation, vitrification and storage of pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. The Cryotop® Thawing Kit is indicated for use in the preparation and thawing of vitrified pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. #### 8. Substantial Equivalence Discussion The following table compares the Cryotop® Vitrification and Thawing Kits to the predicate device with respect to indications for use, principles of operation, technological characteristics, materials, and performance testing. The comparison of the devices provides more detailed information regarding the basis for the determination of substantial equivalence. Based on the information below, the proposed and predicate device have comparable intended uses, and differences in technology noted do not raise different questions of safety or effectiveness as compared to the predicate. | Manufacturer | Kitazato BioPharma Co, Ltd. | Irvine Scientific Sales Co., Inc. | Significant Differences | |---------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------| | Trade Name | Cryotop® Vitrification and Thawing Kits | Vit Kit® - Vitrification Freeze Kit and Vitrification Thaw Kit | | | 510(k) Number | K160864 | K093273 | N/A | | Product Code | MQL, MQK | MQL | Similar | | Regulation Number | 884.6180 | 884.6180 | Same | | Regulation Name | Reproductive Media and Supplements | Reproductive Media and Supplements | Same | | Indications for Use | The Cryotop® Vitrification Kit — Vitrification is indicated for use in the preparation, vitrification and storage of pronuclear (PN) zygotes through day 3 cleavage stage embryos and | Vit Kit® - Freeze, Vitrification Freeze Kit for Embryos (PN through Blastocyst Stage) is intended for use in the vitrification of pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage | Similar indications – same intended use | {6}------------------------------------------------ | Manufacturer | Kitazato BioPharma Co, Ltd. | Irvine Scientific Sales Co., Inc. | Significant Differences | |---------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Trade Name | Cryotop® Vitrification and Thawing Kits | Vit Kit® - Vitrification Freeze Kit and Vitrification Thaw Kit | | | | blastocyst stage embryos. The Cryotop® Thawing Kit – Thawing is indicated for use in the preparation and thawing of vitrified pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. | embryos. Vit Kit® - Thaw, Vitrification Thaw Kit for Embryos (PN through Blastocyst Stage) is intended for use in the thawing of pronuclear (PN) zygotes through day 3 cleavage stage embryos and blastocyst stage embryos. | | | Components of Kit | Vitrification Media Thawing Media Cryotop 35 mm dish Repro Plate | Freeze Kit Vitrification Thaw Kit | Different. During a standard procedure, users would obtain these components separately to complete the procedure. These accessories have been included in this kit as a convenience to complete the procedure. Inclusion of these components does not represent a different question of safety and effectiveness. | | Embryo Stage | PN through Blastocyst | PN through Blastocyst | Same | | Principal of Operation | Provides users with the ability to cryopreserve supernumerary embryos created during the in vitro fertilization | Provides users with the ability to cryopreserve supernumerary embryos created during the in vitro fertilization | Same | {7}------------------------------------------------ | Manufacturer | Kitazato BioPharma Co, Ltd. | Irvine Scientific Sales Co., Inc. | Significant Differences | |----------------------------------|----------------------------------------------------------------------------|----------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Trade Name | Cryotop® Vitrification and Thawing Kits | Vit Kit® - Vitrification Freeze Kit and Vitrification Thaw Kit | | | | procedure and then to re-warm them for use at a future point in time | procedure and then to re-warm them for use at a future point in time | | | Vitrification Formulation | Medium 199 (HEPES buffered Medium) | Medium 199 (HEPES buffered Medium) | Similar; the subject device utilizes trehalose instead of sucrose and HPC instead of DSS in the formulation. However, differences in these components do not raise different questions of safety and effectiveness (e.g., material safety, embryotoxicity, post- thaw survival, etc.). | | | Ethylene glycol | Ethylene glycol | | | | DMSO | DMSO | | | | Trehalose | Sucrose | | | | Hydroxypropyl Cellulose (HPC) | Dextran Serum Supplement (DSS) | | | | Gentamicin | Gentamicin | | | Vitrification Steps | 2 Step | 2 Step | Same | | Vitrification Media Component | Equilibration Solution (ES) 1.5mL x 1 Vial | Equilibration Solution (ES) 1.0mL x 1 Vial | Similar | | | Vitrification Solution (VS) 1.5mL x 2 Vials | Vitrification Solution (VS) 1.0mL x 2 Vials | | | Thawing Formulation | Medium 199 (HEPES buffered Medium) | Medium 199 (HEPES buffered Medium) | Similar; the subject device utilizes trehalose instead of sucrose and HPC instead of DSS in the formulation. However, differences in these components do not raise different questions of safety and effectiveness | | | Hydroxypropyl Cellulose (HPC) (v/v) | Dextran Serum Supplement (DSS) (v/v) | | | | Gentamicin | Gentamicin | | | | Trehalose | Sucrose | | {8}------------------------------------------------ | Manufacturer | Kitazato BioPharma Co, Ltd. | Irvine Scientific Sales Co., Inc. | Significant Differences | |-------------------------------------------------|---------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Trade Name | Cryotop® Vitrification and Thawing Kits | Vit Kit® - Vitrification Freeze Kit and Vitrification Thaw Kit | | | | | | (e.g., material safety, embryotoxicity, post- thaw survival, etc.). | | Thawing Steps | 3 Step | 3 Step | Same | | Thawing Media Component | Thawing Solution (TS) 4.0mL x 2 Vials | Thawing Solution (TS) 1.0mL x 4 Vials | Similar | | | Diluent Solution (DS) 4.0mL x 1 Vial | Diluent Solution (DS) 1.0mL x 1 Vial | | | | Washing Solution (WS) 4.0mL x 1 Vial | Washing Solution (WS) 2.0mL x 1 Vial | | | Carton Packaging | Each solution is contained in plastic vials. Vials are packed in a card board outer box with partition. | Each solution is contained in plastic vials. Vials are packed in a card board outer box with partition. | Same | | Cryopreservation Storage Device Used With | Kitazato BioPharma, Cryotop®CL - K112695 Cryotop®SC - K140072 Cryotop®US - K153027 | None are provided with the kit | Different. During a standard procedure, users would obtain cleared storage devices separately to complete the procedure. Storage devices have been included in this kit as a convenience to complete the procedure. Inclusion of storage devices does not represent a different question of safety and effectiveness. | | Sterile | Solutions sterilized using aseptic processing | Solutions sterilized using aseptic processing | Same | {9}------------------------------------------------ | Manufacturer | Kitazato BioPharma Co, Ltd. | Irvine Scientific Sales Co., Inc. | Significant Differences | |-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Trade Name | Cryotop® Vitrification and Thawing Kits | Vit Kit® - Vitrification Freeze Kit and Vitrification Thaw Kit | | | | techniques through filtration. Vials, vitrification storage device, 35 mm dish, and Repro Plate are sterilized via radiation. | techniques through filtration. Vial containers are sterilized via radiation. | | | Endotoxin | Passes | Passes | Same | | Mouse Embryo Assay | >80% blastocyst at 96 hours (one-cell MEA) | >80% blastocyst at 96 hours (one-cell MEA) | Same | | Sterility Testing | Passes | Passes | Same | | pH Test | 7.20 - 7.60 | Not available | n/a | | Osmolarity | ES: 2,300 - 2,800 VS: 4,900 - 6,000 TS: 1,600 - 2,000 DS: 830 - 1020 WS: 240 - 300 | Not available | n/a | | Storage | 2 – 8°C | 2 – 8°C | Same | | Shelf Life | 6 months | 1 year | Different; the subject device has a shorter shelf life period. The shorter shelf-life does not raise different questions of safety or effectiveness. | #### 9. Non-Clinical Performance Data The Cryotop® Vitrification Kit, Cryotop® Thawing Kit, Repro Plate, and 35 mm dish passed all applicable testing in accordance with internal requirements and applicable standards that are shown below to support substantial equivalence of the subject device: {10}------------------------------------------------ - Cleanliness and appearance: Free of turbidity and sedimentation ● - pH Testing: Average pH reading is from 7.2 – 7.6 passing - . Endotoxin Testing: Endotoxin values conform to the value <0.25 EU/mL - . Osmolality Testing: Passes specification for each solution - Sterility Testing: No microbial growth from sterility testing - . Mouse Embryo Assay: ≥80% of 1-cell control embryos develop at 96 hours - . Package integrity testing #### 10. Clinical Performance Data The clinical information presented provides published papers that specifically identify the use of the Cryotop® and Vitrification/Thawing media with HPC as the vitrification method used for the cryopreservation of embryos and blastocysts from female subjects. A summary of the results are shown below: - Literature 1: results of the study shows clinical pregnancies of 42% from total transfer number and live births of 30% from total transfer number1 - . Literature 2: results of the study shows clinical pregnancies of 59% from number of cycles and ongoing pregnancies of 48% from number of cycles2 - . Literature 3: results of the study shows clinical pregnancies of 49% from number of cycles and ongoing pregnancies of 46% from number of cycles3 The birth rates of vitrified embryo/blastocyst transfer as compared to fresh embryo/blastocyst transfer described in the literature are comparable. Each of the studies reported survival rates of embryos that are consistent with normal ART procedures using similar IVF treatments and cryopreservation techniques. #### 11. Statement of Substantial Equivalence The results of the performance testing described above demonstrates that the Cryotop® Vitrification Kit and Cryotop® Thawing Kit are as safe and effective as the predicate device and supports a determination of substantial equivalence. Kato, K. Takehara, Y. Tomoya, S., Kawachiya, S. Okuno, T. Kobayashi, T. Bodri, D. "Minimal ovarian stimulation combind with elective single embryo transfer policy: age-specific results of a large, single-center, Japanese cohort." Reproductive Biology and Endocrinology 2012, 10:35 ´ Ku, P. Lee, R.K. Lin, S. Lin, M. Hwu, Y. "Comparison of the clinical outcomes between fresh blastocyst and vitrified-thawed blastocyst transfer." J Assist Reprod Genet 2012. 29:1353-56 3 Inoue, F., Yelian, F.. "Efficiency of a Closed Vitrification System with Oocytes and Blastocysts." Low Temperature Medicine 2014. 40/3:53-59