The Clinical Outcome of Ultra-low Oxygen Tension on Post Thawed Human Blastocyst

Study Overview
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Brief Summary
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The clinical outcome of Ultra-low oxygen tension on post thawed human blastocyst

Detailed Description
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In vitro, Embryo development depends on several factors as temperature, pH, and oxygen in the surrounding environment of the embryo. Impaired culture conditions are highly correlated with poor embryo development. Oxygen is a powerful regulator of embryo function , as it is responsible for cell respiration, energy production and rapid cell growth . Increased levels of oxygen is associated with an increase in the levels of ROS , which leads to unfavorable culture conditions, as it might affect the stability of cell membrane, DNA, and protein function . In the female reproductive tract, oxygen concentration fluctuates between 2-8%, which is considered to be at its highest level in the fallopian tube, while the lowest level is in the uterus . Pre-implantation embryo crosses the uterotubal junction after the time of compaction on Day 3, where it is exposed to a shift in oxygen tension to 2%. This variation may have a role in the metabolic reactions of the embryo, and in its preparation for implantation process. Some studies suggested that culturing embryos with oxygen tension below 5% may have an embryological advantage mimicking nature. Embryological laboratories routinely use low Oxygen tension (5%). Our purpose is to investigate if ultra-low oxygen tension (2%) has an advantage over low oxygen tension (5%) for post thawed human embryo regarding clinical outcomes.

Official Title
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The Clinical Outcome of Ultra-low Oxygen Tension on Post Thawed Human Blastocyst

Conditions
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Embryo Development

Intervention / Treatment
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* Other: 5% O2
* Other: 2% O2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Single or Multiple Embryo transfer embryo transfer. Female age 18-40. Embryo vitrified on day 5 or day 6 of insemination. Exclusion Criteria: Use of sperm donation. Use of Oocyte donation. Use of gestational carrier. Uterine congenital anomalies. Presence of any of the endometrial factors that affect embryo implantation such as hydrosalpings, adenomyosis or previously known uterine infection. Any contradictions to undergoing in vitro fertilization or gonadotropin stimulation.

Ages Eligible for Study
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Minimum Age: 5 Days
Maximum Age: 6 Days

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Control arm (5% O2)<br>After thawing, embryos will be cultured in 25 μl drop of pre-equilibrated dishes of media covered with a layer of oil for 1.5 hours at 5.7% CO2, 5% O2, and 89.3% N2 till embryo transfer | Other: 5% O2<br>* Culturing embryos in 5% O2 just after thawing and till embryo transfer<br>|
| Experimental: Experimental arm (2%O2)<br>After thawing, embryos will be cultured in 25 μl drop of pre-equilibrated dishes of media covered with a layer of oil for 1.5 hours at 5.7% CO2, 2% O2, and 92.3% N2 till embryo transfer | Other: 2% O2<br>* Culturing embryos in 2% O2 just after thawing and till embryo transfer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Clinical Pregnancy rate | Defined as the pregnancy that is confirmed by both high levels of hCG and ultrasound confirmation of a gestational sac or heartbeat | Time frame: 15 days following embryo transfer | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ongoing pregnancy rate | Defined as the proportion of pregnancies that had completed ≥20 weeks of gestation | Time frame: 20 weeks of gestation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Thawed blastocyst, ultra low oxygen tension, 2%O2, Degree of expansion