Name: fertility preservation through oocyte vitrification: clinical and laboratory perspectives
Uploaded: 2021-09-16T15:00:00
Description: Watch this Scientific Journal Video about Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives at JoVE.com

1. Work-up and clinical counseling
NOTE: In case of patients requiring fertility preservation for oncologic reasons, ensure that there is no waiting list for scheduling consultation, and the appointment is provided as soon as possible.
<ol>
	<li>Examine the medical history and previous documentation, and assess the patient&#39;s general health status.</li>
	<li>Record all information (including the oncologist&#39;s approval to undergo ovarian stimulation in case of cancer patients) in a rela...

Clinical considerations 
Although emerging strategies, such as ovarian tissue cryopreservation and in vitro maturation, have been explored, oocyte vitrification after COS is the gold standard technique for fertility preservation. In this scenario, the number of oocytes retrieved and cryopreserved should be maximized in the shortest possible time as most cancer patients might benefit solely from one ovarian cycle before they have to commence their cancer treatment(s). Thus, a p...

The development and implementation of an efficient cryopreservation program for human oocytes has been a significant breakthrough in reproductive medicine. According to recent evidence, vitrification is the most effective strategy to cryopreserve metaphase II (MII) oocytes, as it results in statistically higher survival rates compared to slow freezing, independently of the patient population (infertile patients or oocyte donation program)1,2,3. The remarkable achievements of oocyte vitrification led the Practice Committees of the American Society for Reproductive Medicine (ASRM) and the Society for Assisted Reproductive Technology (SART) to pronounce this technique to be the most effective for elective fertility preservation in postpubertal women, for both medical and non-medical indications4,5,6. Medical indications for fertility preservation include (i) cancer and autoimmune diseases that require therapies7 such as radiotherapy, cytotoxic chemotherapy, and endocrine therapy (whose detrimental effect on the ovarian reserve is associated with maternal age as well as type and dose of the treatment); (ii) ovarian diseases requiring repeated or radical surgery (such as endometriosis)8; and (iii) genetic conditions (e.g., X-fragile) or premature ovarian failure. In addition, fertility preservation has become a valuable option for all women who have not accomplished their parental objective for non-medical reasons (also known as social freezing).
Regardless of the indication for fertility preservation and according to the major international guidelines on fertility preservation, all patients willing to vitrify their oocytes should receive appropriate counseling to be informed about their realistic chance of success, the costs, risks, and limitations of the procedure9,10,11,12,13. Most importantly, it should be clear that vitrifying a cohort of MII oocytes does not ensure a pregnancy, but that it offers a higher chance of success for future in vitro fertilization (IVF) treatment, if necessary14. In this regard, the woman&#39;s age at the time of oocyte vitrification is certainly the most important limiting factor15 as advanced maternal age (AMA; &#62;35 years) is the main cause of female infertility16. Besides a progressive reduction in the ovarian reserve, AMA is associated with an impairment of oocyte competence due to defective physiological pathways such as metabolism, epigenetic regulation, cell cycle checkpoints, and meiotic segregation17. Therefore, the reasonable number of eggs to vitrify mainly depends on maternal age. In women younger than 36 years, at least 8-10 MII oocytes18 are required to maximize the chance of success. In general, the higher the number of vitrified oocytes, the higher is the likelihood of success. Therefore, tailoring ovarian stimulation according to ovarian reserve markers such as anti-M&#252;llerian hormone (AMH) levels or antral follicle count (AFC) is crucial to fully exploit the ovarian reserve in the shortest possible time.
The safety of the whole procedure is the other key issue when enrolling patients for fertility preservation. Clinicians should employ the best strategies to minimize the risks and prevent (i)ovarian hyperstimulation syndrome (OHSS) by using safe approaches such as the gonadotrophin-releasing hormone (GnRH) antagonist protocol followed by a GnRH agonist trigger19 and (ii) the remote, yet possible, risks of peritoneal bleeding, injury to the pelvic structures (ureter, bowel, appendix, nerves), or pelvic infection during oocyte retrieval. Lastly, (iii) traditional regimens for stimulation are associated with supraphysiologic serum estradiol and therefore, are not recommended in estrogen-sensitive diseases such as breast cancer. Protocols involving aromatase inhibitors (such as letrozole or tamoxifen) are more suitable in these cases20,21. In the laboratory setting, the most widespread protocol for oocyte vitrification is still the one first described by Kuwayama and colleagues2,23, which consists of a stepwise procedure involving the gradual addition of cryoprotectants (CPAs). In the first phase (equilibrium/dehydration), oocytes are exposed in a CPA solution containing 7.5% v/v ethylene glycol and 7.5% v/v dimethyl sulfoxide (DMSO), while in the second phase, oocytes are moved to a vitrification solution with 15% v/v ethylene glycol and 15% v/v DMSO, plus 0.5 mol/L sucrose. After a short incubation in the medium of vitrification, the oocytes can be placed in specifically designed, open cryodevices and finally plunged in liquid nitrogen at -196 &#176;C to be stored until use.
Here, the whole clinical and laboratory work-up of a fertility preservation treatment has been described by (i) outlining recommendations for objective and evidence-based counseling, (ii) focusing on the cost-effectiveness of the procedure, and (iii) describing the most appropriate strategies to fully exploit the ovarian reserve and maximize the number of oocytes retrieved in the shortest possible time. The evaluation of the ovarian reserve, the definition of an ideal stimulation protocol, as well as oocyte retrieval, denudation, and vitrification procedures will be detailed along with approaches to maximize their efficacy, efficiency, and safety. As other protocols or adaptations of this protocol exist in the literature, the representative results and the discussion sections of this manuscript only apply to this procedure.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Collection</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hot plate</td>
			<td>IVF TECH</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lab Markers</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laminar Flow Hood</td>
			<td>IVF TECH</td>
			<td></td>
			<td>Grade A air flow</td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>Leica</td>
			<td>Leica M80</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermometer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Test tube Warmer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tri-gas incubator</td>
			<td>Panasonic</td>
			<td>MCO-5M-PE</td>
			<td>02/CO2</td>
		</tr>
		<tr>
			<td>Vacuum Pump</td>
			<td>Cook</td>
			<td>K-MAR-5200</td>
			<td></td>
		</tr>
		<tr>
			<td>Consumables</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>CSCM (Continuos single culture complete) medium</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90165</td>
			<td>IVF culture medium supplemented with HSA</td>
		</tr>
		<tr>
			<td>Mineral Oil for embryo culture</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>9305</td>
			<td></td>
		</tr>
		<tr>
			<td>Ovum Aspiration Needle (Single lumen)</td>
			<td>Cook</td>
			<td colspan="2">K-OSN-1730-B-60</td>
		</tr>
		<tr>
			<td>Primaria Dish</td>
			<td>Corning</td>
			<td>353803</td>
			<td>Corning Primaria Dish 100x20 mm style standard cell culture dish</td>
		</tr>
		<tr>
			<td>Round- bottom tubes</td>
			<td>Falcon</td>
			<td>352001</td>
			<td>Falcon 14ml Round Bottom Polystyrene Test tube with snap cap</td>
		</tr>
		<tr>
			<td>Round- bottom tubes</td>
			<td>Falcon</td>
			<td>352003</td>
			<td>Oocyte collection tubes/ Falcon 5ml 12x75 Round Bottom Polipropilene Test tube with snap cap</td>
		</tr>
		<tr>
			<td>Rubber Bulb</td>
			<td>Sigma Aldrich</td>
			<td>Z111589-12EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile glass Pasteur pipettes</td>
			<td>Hunter Scientific</td>
			<td>PPB150-100PL</td>
			<td>Pipette Pasteur Cotonate, 150mm, MEA e CE</td>
		</tr>
		<tr>
			<td>Denudation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>CO2 incubator</td>
			<td>Eppendorf</td>
			<td>Galaxy 14S</td>
			<td></td>
		</tr>
		<tr>
			<td>Flexipet adjustable handle set</td>
			<td>Cook</td>
			<td>G18674</td>
			<td>Stripper&#160; holder</td>
		</tr>
		<tr>
			<td>Gilson Pipetman</td>
			<td>Gilson</td>
			<td>66003</td>
			<td>p20</td>
		</tr>
		<tr>
			<td>k-System Incubator</td>
			<td>Coopersurgical</td>
			<td>G210Invicell</td>
			<td></td>
		</tr>
		<tr>
			<td>Lab Markers</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laminar Flow Hood</td>
			<td>IVF TECH</td>
			<td></td>
			<td>Grade A air flow</td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>Leica</td>
			<td>Leica M80</td>
			<td></td>
		</tr>
		<tr>
			<td>Consumables</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Biopur epTIPS Rack</td>
			<td>Eppendorf</td>
			<td>30075331</td>
			<td>Micropipettes epTIPS Biopur 2-200 &#181;l</td>
		</tr>
		<tr>
			<td>Human Serum Albumin</td>
			<td>thermoFisher Scietific</td>
			<td>9988</td>
			<td></td>
		</tr>
		<tr>
			<td>Hyaluronidase</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90101</td>
			<td>80 IU/mL of hyaluronidase enzyme in HEPES-buffered HTF</td>
		</tr>
		<tr>
			<td>IVF culture dish (60 x 15mm)</td>
			<td>Corning</td>
			<td>353802</td>
			<td>Corning Primaria Falcon Dish 60X15mm TC Primaria standard cell culture dish</td>
		</tr>
		<tr>
			<td>IVF dish 4-well plate with sliding lid</td>
			<td>ThermoFisher Scietific</td>
			<td>176740</td>
			<td>Multidishes 4 wells (Nunc)</td>
		</tr>
		<tr>
			<td>IVF One well dish</td>
			<td>Falcon</td>
			<td>353653</td>
			<td>Falcon 60 x 15 mm TC treated center-well IVF</td>
		</tr>
		<tr>
			<td>Mineral Oil for embryo culture</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>9305</td>
			<td></td>
		</tr>
		<tr>
			<td>Modified HTF Medium</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90126</td>
			<td>HEPES-Buffered medium</td>
		</tr>
		<tr>
			<td>Rubber Bulb</td>
			<td>Sigma Aldrich</td>
			<td>Z111589-12EA</td>
			<td>1 mL for pasteur pipettes</td>
		</tr>
		<tr>
			<td>Sterile glass Pasteur pipettes</td>
			<td>Hunter Scientific</td>
			<td>PPB150-100PL</td>
			<td>Pipette Pasteur Cotonate, 150 mm, MEA e CE</td>
		</tr>
		<tr>
			<td>stripping pipette&#160; tips (140 &#181;m)</td>
			<td>Cook</td>
			<td>K-FPIP-1140-10BS-6</td>
			<td>PIPETTE FLEXIPETS PER DENUDING</td>
		</tr>
		<tr>
			<td>stripping pipette tips (130 &#181;m )</td>
			<td>Cook</td>
			<td>K-FPIP-1130-10BS-7</td>
			<td>PIPETTE FLEXIPETS PER DENUDING</td>
		</tr>
		<tr>
			<td>stripping pipette tips (170 &#181;m)</td>
			<td>Cook</td>
			<td>K-FPIP-1170-10BS-5</td>
			<td>PIPETTE FLEXIPETS PER DENUDING</td>
		</tr>
		<tr>
			<td>Vitrification</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Electronic Timer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Flexipet adjustable handle set</td>
			<td>Cook</td>
			<td>G18674</td>
			<td>Stripper&#160; holder</td>
		</tr>
		<tr>
			<td>Gilson Pipetman</td>
			<td>Gilson</td>
			<td>F123601</td>
			<td>p200</td>
		</tr>
		<tr>
			<td>Lab Markers</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laminar Flow Hood</td>
			<td>IVF TECH</td>
			<td></td>
			<td>Grade A air flow</td>
		</tr>
		<tr>
			<td>Stainless Container for Cooling Rack</td>
			<td>Kitazato</td>
			<td></td>
			<td>Liquid nitrogen container for vitrification</td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>Leica</td>
			<td>Leica M80</td>
			<td></td>
		</tr>
		<tr>
			<td>Consumables</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Biopur epTIPS Rack</td>
			<td>Eppendorf</td>
			<td>30075331</td>
			<td>Micropipettes epTIPS Biopur 2-200 &#181;L</td>
		</tr>
		<tr>
			<td>Human Serum Albumin</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>9988</td>
			<td></td>
		</tr>
		<tr>
			<td>IVF culture dish (60 x 15 mm)</td>
			<td>Corning</td>
			<td>353802</td>
			<td>Corning Primaria Falcon Dish 60 x 15 mm TC Primaria standard cell culture dish</td>
		</tr>
		<tr>
			<td>IVF dish 6-well</td>
			<td>Oosafe</td>
			<td>OOPW-SW02</td>
			<td>OOSAFE&#160;6 WELL DISH WITH STRAW HOLDER</td>
		</tr>
		<tr>
			<td>Modified HTF Medium</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90126</td>
			<td>HEPES-Buffered medium</td>
		</tr>
		<tr>
			<td>stripping pipette tips (170 &#181;m)</td>
			<td>Cook</td>
			<td>K-FPIP-1170-10BS-5</td>
			<td>PIPETTE FLEXIPETS PER DENUDING</td>
		</tr>
		<tr>
			<td>Vitrification Freeze kit</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90133-so</td>
			<td>2 Vials of ES (Equilibration Solution, 2 x 1 mL) and 2 Vials of VS (Vitrification Solution, 2 x 1 mL)</td>
		</tr>
		<tr>
			<td>Vitrifit</td>
			<td>Coopersurgical Origio</td>
			<td>42782001A</td>
			<td>VitriFit&#160; Box</td>
		</tr>
		<tr>
			<td>Warming</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Electronic Timer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Flexipet adjustable handle set</td>
			<td>Cook</td>
			<td>G18674</td>
			<td>Stripper&#160; holder</td>
		</tr>
		<tr>
			<td>Gilson Pipetman</td>
			<td>Gilson</td>
			<td>F123601</td>
			<td>p200</td>
		</tr>
		<tr>
			<td>k-System Incubator</td>
			<td>Coopersurgical</td>
			<td>G210Invicell</td>
			<td></td>
		</tr>
		<tr>
			<td>Lab Markers</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laminar Flow Hood</td>
			<td>IVF TECH</td>
			<td></td>
			<td>Grade A air flow</td>
		</tr>
		<tr>
			<td>Stainless Container for Cooling Rack</td>
			<td>Kitazato</td>
			<td></td>
			<td>Liquid nitrogen container for vitrification</td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>Leica</td>
			<td>Leica M80</td>
			<td></td>
		</tr>
		<tr>
			<td>Consumables</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Biopur epTIPS Rack</td>
			<td>Eppendorf</td>
			<td>30075331</td>
			<td>Micropipettes epTIPS Biopur 2-200 &#181;L</td>
		</tr>
		<tr>
			<td>CSCM (Continuos single culture complete) medium</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90165</td>
			<td>IVF culture medium supplemented with HSA</td>
		</tr>
		<tr>
			<td>IVF culture dish (60 x 15 mm)</td>
			<td>Corning</td>
			<td>353802</td>
			<td>Corning Primaria Falcon Dish 60X15mm TC Primaria standard cell culture dish</td>
		</tr>
		<tr>
			<td>IVF dish 4-well plate with sliding lid</td>
			<td>ThermoFisher Scietific</td>
			<td>176740</td>
			<td>Multidishes 4 wells (Nunc)</td>
		</tr>
		<tr>
			<td>IVF dish 6-well</td>
			<td>Oosafe</td>
			<td>OOPW-SW02</td>
			<td>OOSAFE&#174;&#160;6 WELL DISH WITH STRAW HOLDER</td>
		</tr>
		<tr>
			<td>Mineral Oil for embryo culture</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>9305</td>
			<td></td>
		</tr>
		<tr>
			<td>SAtripping pipette tips (300&#181;m)</td>
			<td>Cook</td>
			<td>K-FPIP-1300-10BS-5</td>
			<td>PIPETTE FLEXIPETS PER DENUDING</td>
		</tr>
		<tr>
			<td>Vitrification Thaw kit</td>
			<td>Fujifilm Irvine Scientific</td>
			<td>90137-so</td>
			<td>4 Vials of TS (Thawing Solution, 4 x 2 mL) + 1 Vial of DS (Dilution Solution, 1 x 2 mL) +1 Vial of WS (Washing Solution, 1 x 2 mL)</td>
		</tr>
	</tbody>
</table>

fertility preservation through oocyte vitrification: clinical and laboratory perspectives

Preserving female fertility is crucial in a multifunctional healthcare system that takes care of patients' future quality of life. Oocyte cryopreservation is recognized by several international scientific societies as the gold standard for fertility preservation in postpubertal women, for both medical and non-medical indications. The main medical indications are oncologic diseases, gynecologic diseases such as severe endometriosis, systemic diseases compromising the ovarian reserve, and genetic conditions involving premature menopause. This paper describes the whole clinical and laboratory work-up of a fertility preservation treatment by outlining recommendations for objective and evidence-based counseling. Furthermore, it focuses on the effectiveness of the procedure and describes the most appropriate strategies to fully exploit the ovarian reserve and maximize the number of oocytes retrieved in the shortest possible time. The evaluation of the ovarian reserve, the definition of an ideal stimulation protocol, as well as oocyte retrieval, denudation, and vitrification procedures have been detailed along with approaches to maximize their efficacy, efficiency, and safety.

Overview of the fertility preservation program at the center
Over a 12-year period (2008-2020), 285 women underwent at least one oocyte retrieval entailing the vitrification of the whole cohort of mature eggs collected. Most of these women (n=250) underwent a single retrieval, and 35 underwent multiple retrievals. The reasons for undergoing oocyte retrieval for egg vitrification are summarized into 4 categories: medical (except for cancer), cancer, non-medical, and others. Amo...

Watch this Scientific Journal Video about Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives at JoVE.com

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives

Oocyte cryopreservation is recognized by several international scientific societies as the gold standard for fertility preservation in postpubertal women. Appropriate clinical and laboratory strategies ensure maximum efficacy, efficiency, and safety of fertility preservation treatments.

Preserving female fertility is crucial in a multifunctional healthcare system that takes care of patients' future quality of life. Oocyte cryopreservation ...

The oocyte vitrification and the warming procedures are essential for fertility preservation. Following this protocol as demonstrated allow a user to maximize the effectiveness of these procedures. Fertility preservation for oocyte vitrification is today an established and ethically acceptable approach.It allow to achieve effective and consistent clinical outcomes and overcome the moral and legal limitation associated with embryo cryopreservation. To achieve proficiency with the vitrification process, it is important to become familiar with all the critical points of the protocol, paying particular attention to the exposure time of the samples to the cryoprotectants. Within 38 hours of retrieval and immediately after denudation, label all of the plastic supplies with the patient's name, ID, and type of solution, and ask a witness to confirm the patient's information on the cryo device.When all of the supplies have been labeled, carefully invert each vial of oocytes several times to mix and place a 30 microliter drop of HEPES buffer medium supplemented with human serum albumin and a 30 microliter adjacent drop of equilibration solution on a petri dish. Use the stripper pipette to place the oocytes in the first drop and create a bridge of medium to a 30 microliter drop of equilibration solution to obtain a gradual increase in concentration of the cryoprotectants. After three minutes, add a second 30 microliter drop of equilibration solution to the plate and use the pipette to create a medium bridge between the drops of solution.While the oocytes are equilibrating, add one 30 microliter drop of equilibration solution for each cryo device to be used onto the plate. After three minutes, move the oocytes into the pure equilibration solution for six to nine minutes to allow the oocytes to return to their initial size. When the oocytes have recovered, prepare a central well IVF dish containing one milliliter of vitrification solution.Transfer the oocytes to the dish in as little medium as possible and carefully move them to remove any excess equilibration solution. Approximately 10 seconds before the end of the incubation, place a cryo device labeled with the patient's information under the microscope and adjust the focus on the tip of the cryo device. Place the oocytes on the cryo device beside the tip in the minimum amount of vitrification solution and move the stripper pipette away from the oocytes to remove any excess vitrification solution, leaving the oocytes covered with a thin layer of medium.Quickly plunge the cryo device into liquid nitrogen and rapidly shake the device to remove any air bubbles from its surface. Holding the protective cap of the cryo device with tweezers, fill the cap with liquid nitrogen before inserting the device into the cap while keeping the propylene strips in liquid nitrogen. Then store the cryo device in a visotube labeled with the patient's information and update the laboratory sheet.For oocyte warming, carefully invert each vial of thawing, dilution, and washing solution warmed to room temperature, and add one milliliter of thawing solution to the central well of a petri dish for an at least one hour incubation at 37 degrees Celsius. Label all of the plastic supplies with the patient's name and ID and the type of solution, and ask a witness to confirm the patient's information on the cryo device. For each device to be warmed, add 200 microliters of dilution solution to the first well of a six well plate and add an equal volume of washing solution to the second and third wells of the plate.Add PBS to the area on the outside of the wells to prevent solution evaporation. Place the dish of thawing solution under the stereo microscope and adjust the focus to the center of the dish. Carefully twist to remove the protective cap of a cryo device while keeping the propylene strips in liquid nitrogen and transfer the cryo device from the liquid nitrogen into the thawing solution as quickly as possible to avoid the risk of devitrification.After one minute, focus on the tip of the cryo device to locate the oocytes and eventually use a stripper pipette to gently release the oocytes from the device. Use a 170 micron diameter stripper pipette to transfer the oocytes and a small volume of thawing solution into the dilution solution in the first well of the six well plate. After three minutes, move the oocytes into the first well of washing solution for five minutes.At the end of the incubation, transfer the oocytes to the second well of washing solution and incubate at 37 degrees Celsius for one minute before transferring the oocytes into an appropriate volume of pre-equilibrated IVF culture medium for one hour and updating the laboratory sheet. Over a 12 year period, 285 women underwent at least one oocyte retrieval entailing the vitrification of the whole cohort of mature eggs collected. Most of these women underwent a single retrieval.35 underwent multiple retrievals. The reasons for undergoing oocyte retrieval for egg vitrification were generally characterized as medical other than cancer, cancer, nonmedical, and other. Patients with a medical reason for egg vitrification and patients undergoing fertility preservation because of cancer were younger and showed higher antral follicular counts than patients with nonmedical or other reasons.However, as the mean maturation rates were slightly lower in the medical reasons patients, the number of oocytes vitrified on average was similar between the groups. Approximately half of the patients with medical reasons other than cancer, and the majority of patients with other reasons for egg vitrification actually returned for warming. Conversely, very few patients who underwent fertility preservation for cancer or nonmedical reasons used their vitrified oocytes for IVF.Despite differences in the time elapsed between vitrification and warming, the survival rate of the oocytes was similar between patient groups, confirming the efficacy and safety of the oocyte vitrification and warming protocols. Moreover, the survival rate was independent of the vitrification and warming operator's experience. The most crucial steps that may affect the consistency of the results are the one related with warming.Therefore, it is really important to carefully control the volume and the temperature of the thawing solutions. Ovarian tissue cryopreservation the only strategy currently under investigation as an option for pre-pubertal patients. Although promising, this approach has important limitation which limited its application.

Research

JoVE Journal

Medicine

Imaging Glioma Initiation In Vivo Through a Polished and Reinforced Thin-skull Cranial Window

Imaging Glioma Initiation In Vivo Through a Polished and Reinforced Thin-skull Cranial Window

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Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

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Introduction of Intracapsular Rotary-cut Procedures (IRCP): A Modified Hysteromyomectomy Procedures Facilitating Fertility Preservation

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Remote Laboratory Management: Respiratory Virus Diagnostics

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Learning Modern Laryngeal Surgery in a Dissection Laboratory

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Orthotopic Kidney Auto-Transplantation in a Porcine Model Using 24 Hours Organ Preservation And Continuous Telemetry

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OP-IVM: Combining In vitro Maturation after Oocyte Retrieval with Gynecological Surgery

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Fertility Preservation in Patients with Severe Ovarian Dysfunction

Ovarian function progressively declines during aging and in some pathophysiological conditions including karyotype abnormality, autoimmune diseases, ...

Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury

Myocardial ischemia and reperfusion injury (MIRI), induced by coronary heart disease (CHD), causes damage to the cardiomyocytes. Furthermore, evidence ...