Effect of Reducing the Oxygen Concentration From 5% to 2% on ICSI Outcome

July 8, 2023 updated by: Ahmed EL-Sayed Sabry Metwally, International Islamic Center for Population Studies and Research

Effect of Reducing the Oxygen Concentration From 5% to 2% on Intracytoplasmic Sperm Injection (ICSI) Outcome

To assess the effect of reducing the oxygen concentration from 5% to 2% on Intracytoplasmic sperm injection (ICSI) outcome.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Oxygen level plays a critical role in reducing the high level of detrimental reactive oxygen species within cells, influences embryonic gene expression, helps with embryo metabolism of glucose, and enhances embryo development from 2PN to the blastocyst stage, the oxygen concentration in the incubator is an important determinant of the in vitro environment that an embryo encounters. The preimplantation embryo consumes oxygen at a relatively constant level from the one-cell through the morula stage, while at the blastocyst stage the consumption is considerably increased. Oxygen plays a role in energy production, but in too high concentrations it may have a toxic effect by the formation of reactive oxygen species. While in vivo oxygen levels range from 1.5 to 8.7% in the fallopian tubes and uterus of several species, in most laboratories in vitro culture of human embryos was traditionally performed under atmospheric oxygen concentrations (~20%) . In mammals, the oxygen (O2) tension in the uterus is lower (2%) than the oviduct (5-7%). This fits with a shift in the metabolic strategy of the embryo after compaction and may have implications for EC in clinical IVF. Indeed, in a recent study utilizing discarded human embryos, blastulation rates were superior when cultured in 2% compared to 5% after day day 3. However, it is exceedingly difficult to control for the myriad factors impacting blastulation when employing discarded material . The technologies available in the early days of IVF, and most likely also for financial reasons, led to the widespread implementation of incubators that used atmospheric air (i.e. 20% oxygen) . Around the turn of the last century, more advanced incubators capable of creating an environment of 5% oxygen, which better resembles the natural

environment for oocytes and embryos, were developed. Currently, in around 60% of the IVF cycles performed worldwide, the embryos are cultured under 5% oxygen . Kaser et al. add to the long history of experimental data evaluating different oxygen levels in embryo culture. They evaluated the impact of a sequential oxygen tension system (5% oxygen from day 1 to day 3; 2% oxygen from day 3 to day 5) in extended culture . The effect of oxygen level during embryo culture on pregnancy and live birth rates is less straightforward. Although most studies found an improvement in embryo quality when culturing embryos under 5% oxygen . This discrepancy is partly explained by lack of power due to small sample sizes in some studies. When data are pooled in meta-analyses, the overall effect favours culture under 5% oxygen . Another explanation for the inconsistent results among the studies could be due to the differences in duration of exposure, until cleavage or blastocyst stage. When data in the meta-analyses were stratified for duration of culture, there was no effect of oxygen on pregnancy or live birth rates after 2-3 days of culture. After culture to the blastocyst stage, however, culture under 5% oxygen resulted in improved ongoing pregnancy. In the previous studies reported that culture under 5% O2 results in significantly more human surplus embryos reaching the blastocyst stage, as well as a higher proportion of blastocysts consisting of a normal number of cells.

in the human, indirect evidence exists that a low O2 tension of 5% appears to enhance the blastulation rate of surplus embryos .

A reduction in oxygen tension from atmospheric to more physiologic levels is beneficial for the mammalian blastocyst, in terms of a higher cell number and decreased apoptosis, less DNA fragmentation and less oxidative stress. During this highly metabolically active period of growth of the embryo and differentiation into trophectoderm (TE) and inner cell mass (ICM), this decrease in oxygen may protect against oxidative stress .

Study Type

Interventional

Enrollment (Estimated)

196

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Egypt
      • Cairo, Egypt, 11511
        • Recruiting
        • International Islamic Center
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

- Female age 20-35 years. Oocytes with normal morphology.

Exclusion Criteria:

  • Embryo number less than 5. Male factor.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group of 2% oxygen concentration.
Incubate human embryo at 2% oxygen concentration.
Other: Reducing the Oxygen Concentration From 5% to 2%
Effect of Reducing the Oxygen Concentration From 5% to 2% in arm 1.
No Intervention: Group of 5% oxygen concentration.
Incubate human embryo at 5% oxygen concentration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number and grad of embryos which exposed to oxygen concentration 2% .
Time Frame: 1.3 year
Evaluate embryo quality at day 5
1.3 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical pregnancy rate for examined subject.
Time Frame: 1.5 Year
Compare the two arms in clinical pregnancy.
1.5 Year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

International Islamic Center for Population Studies and Research

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2023

Primary Completion (Estimated)

January 27, 2024

Study Completion (Estimated)

March 25, 2024

Study Registration Dates

First Submitted

June 18, 2023

First Submitted That Met QC Criteria

June 18, 2023

First Posted (Actual)

June 29, 2023

Study Record Updates

Last Update Posted (Actual)

July 11, 2023

Last Update Submitted That Met QC Criteria

July 8, 2023

Last Verified

June 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • O2 level in human embryo

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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