Optimization of Oocyte Warming Protocols

Optimization of Oocyte Warming Protocols: a Comparative Study of Standard, Rapid, and Ultra-rapid Techniques on Oocyte Survival Rate and Spindle Morphometry

Status

Active, not recruiting

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT07105891

Acronym

OVOfast

Enrollment

399

Registered

2025-08-06

Start date

2025-09-16

Completion date

2025-10-30

Last updated

2025-10-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Oocyte Cryopreservation

Keywords

oocytes, thawing, art, vitrification, warming, survival rates

Brief summary

This is a retrospective study with a sibling design comparing new oocyte thawing protocols (rapid and ultra-rapid) with the traditional method

Interventions

OTHERThawing protocol

Standard thwaing

OTHERthawing protocol

Fast thawing

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

NONE

Intervention model description

sibling design

Eligibility

Sex/Gender

FEMALE

Age

18 Years to 40 Years

Healthy volunteers

Yes

Inclusion criteria

* Vitrified oocytes from the Centro Scienze della Natalità, IRCCS San Raffaele Hospital * Patients who explicitly consented to the disposal of their stored gametes and authorized their use for research purposes through the informed consent process * Oocytes cryopreserved using the vitrification technique * Patients age 20-39 yo

Exclusion criteria

* All oocytes cryopreserved using the slow freezing technique * Oocytes from patients older than 40 years

Design outcomes

Primary

Measure	Time frame	Description
Oocytes Survival rate	2 hours post-warming	Oocyte survival rate will be assessed 2 hours after thawing using morphological evaluation under a light microscope. Surviving oocytes will be identified by the presence of an intact zona pellucida and oolemma, a round shape, and homogeneous cytoplasm without signs of lysis, fragmentation, or cytoplasmic granulation.

Secondary

Measure	Time frame	Description
Spindle configuration	2 hours post thawing	Spindle configuration in thawed oocytes will be assessed using confocal microscopy following immunofluorescence staining. The spindles will be classified as normal, slightly aberrant, or aberrant.
Chromosome distribution	2 hours post thawing	Chromosome distribution will be assessed using confocal microscopy following immunofluorescence staining. The distribution will be classified as normal, misaligned, or displaced.

Countries

Italy

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026