Oxygen Tension on Human Embryonic Development

Infertility Clinical Trial

— EmbryOx  

Official title:

Impact of Low Versus Atmospheric Oxygen Tension on Human Embryo Development : A Prospective Randomized Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03964805
• Other study ID #: 2015-A02019-40
• Status: Completed
• Phase: N/A
• Start date: September 1, 2016
• Est. completion date: December 1, 2018

Study information

• Verified date: April 2019
• Source: Assistance Publique - Hôpitaux de Paris
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

In mammals, uterine environment is at low oxygen concentration (2-8% O2). Thus, human embryo culture under low O2 tension (5%) is now recommended by European Society of Human Reproduction and Embryology (ESHRE) revised guidelines for good practices in in vitro fertilization (IVF) labs. Indeed, hypoxia seems to improve embryo quality at cleavage and blastocyst stages, presumably by reducing damages of oxidative stress (OS). Nevertheless, recent meta-analyses concluded only with a low evidence to a superiority of hypoxia on IVF/ICSI outcomes. Furthermore, a study on mouse embryos suggested a negative impact of OS only at cleavage stage. The aim of the present prospective randomized study was to investigate this hypothesis for the first time in human embryos.

Description:

In mammals, uterine environment is at low oxygen tension, between 2 and 8% O2 . However, most IVF labs perform embryo culture at atmospheric tension (around 20% O2). Several randomized studies in human embryos have reported the superiority of hypoxia (5%) in terms of embryo quality and blastulation rates. This fact might be explained by a more physiological environment, probably inducing a decrease in oxidative stress (OS), which has a harmful impact on embryo development. Other studies have also suggested that before compaction, OS damages might be irreversible.

Wale et Gardner have investigated this impact of oxygen tension on mouse embryo development, by comparing four culture conditions: (i) group 1: culture exclusively at 5% O2 ; (ii) group 2: culture at 5% from Day 0 to Day 2, then at 20% from Day 2 to Day 4; (iii) group 3: at 20% then at 5% from Day 2; (iv) and group 4: culture exclusively at 20% Interestingly, no difference in terms of blastulation had been reported between groups 1 and 2, suggesting the OS might impact only at cleavage stage, and that switching culture under atmospheric conditions from Day 2/3 might not influence embryo development thereafter.

Hence, all those investigations suggest that embryo culture using trigas incubators (5% O2, 6% CO2 and 89% N2) would be preferable. However, this system is very expensive, notably due to a high N2 consumption, and requires a more complicated logistics (e.g. N2 levels monitoring). Yet, Wale and Gardner's results imply that sequential culture conditions (trigas from Day 0 to Day 2/3, then conventional incubator at 20% O2 until blastocyst stage) could be an valuable option, reducing the costs and, essentially, without any detrimental impact on embryo development.

The present study has two main objectives: (i) to confirm the improvement in embryo quality under low oxygen tension and (ii) to demonstrate the negative impact of OS only at cleavage stage in human embryos, as assumed by Wale and Gardner. For that purpose, we designed an original prospective randomized study comparing three culture conditions: (i) culture excusively at 20% O2 (Day 0 to Day 6) (Group A); (ii) culture exclusively at 5% O2 (Day 0 to Day 6) (Group B); (iii) culture at 5% from Day 0 to Day 3, then at 20% from Day 3 to Day 6) (Group C). Inclusion criteria and outcome measures are detailed in the following sections.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 773
• Est. completion date: December 1, 2018
• Est. primary completion date: September 6, 2018
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 39 Years

Eligibility

Inclusion Criteria:

• Age: 18 - 39 years

• IVF / ICSI Attempt with Ejaculated Sperm Sperm (Fresh or Frozen)

• At least 8 oocytes retrieved in total

• Good understanding of the protocol by the patient

• Informed and consentment signed of the couple

Exclusion Criteria:

• - Hydrosalpinx

Related Conditions & MeSH terms

• Embryo Culture
• Hypoxia
• Infertility

Intervention

Other:
• 20% oxygen
culture excusively at 20% O2 (Day 0 to Day 6)
• 5% oxygen
culture excusively at 5% O2 (Day 0 to Day 6)
• 20 % and 5 % oxygen
culture at 5% from Day 0 to Day 3, then at 20% from Day 3 to Day 6)

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Assistance Publique - Hôpitaux de Paris

References & Publications (10)

Ciray HN, Aksoy T, Yaramanci K, Karayaka I, Bahceci M. In vitro culture under physiologic oxygen concentration improves blastocyst yield and quality: a prospective randomized survey on sibling oocytes. Fertil Steril. 2009 Apr;91(4 Suppl):1459-61. doi: 10.1016/j.fertnstert.2008.07.1707. Epub 2008 Aug 22. — View Citation

Fischer B, Bavister BD. Oxygen tension in the oviduct and uterus of rhesus monkeys, hamsters and rabbits. J Reprod Fertil. 1993 Nov;99(2):673-9. — View Citation

Guo N, Li Y, Ai J, Gu L, Chen W, Liu Q. Two different concentrations of oxygen for culturing precompaction stage embryos on human embryo development competence: a prospective randomized sibling-oocyte study. Int J Clin Exp Pathol. 2014 Aug 15;7(9):6191-8. eCollection 2014. — View Citation

Kasterstein E, Strassburger D, Komarovsky D, Bern O, Komsky A, Raziel A, Friedler S, Ron-El R. The effect of two distinct levels of oxygen concentration on embryo development in a sibling oocyte study. J Assist Reprod Genet. 2013 Aug;30(8):1073-9. doi: 10.1007/s10815-013-0032-z. Epub 2013 Jul 9. — View Citation

Kea B, Gebhardt J, Watt J, Westphal LM, Lathi RB, Milki AA, Behr B. Effect of reduced oxygen concentrations on the outcome of in vitro fertilization. Fertil Steril. 2007 Jan;87(1):213-6. Epub 2006 Nov 1. — View Citation

Kirkegaard K, Hindkjaer JJ, Ingerslev HJ. Effect of oxygen concentration on human embryo development evaluated by time-lapse monitoring. Fertil Steril. 2013 Mar 1;99(3):738-744.e4. doi: 10.1016/j.fertnstert.2012.11.028. Epub 2012 Dec 11. — View Citation

Kovacic B, Vlaisavljevic V. Influence of atmospheric versus reduced oxygen concentration on development of human blastocysts in vitro: a prospective study on sibling oocytes. Reprod Biomed Online. 2008 Aug;17(2):229-36. — View Citation

Waldenström U, Engström AB, Hellberg D, Nilsson S. Low-oxygen compared with high-oxygen atmosphere in blastocyst culture, a prospective randomized study. Fertil Steril. 2009 Jun;91(6):2461-5. doi: 10.1016/j.fertnstert.2008.03.051. Epub 2008 Jun 12. — View Citation

Wale PL, Gardner DK. The effects of chemical and physical factors on mammalian embryo culture and their importance for the practice of assisted human reproduction. Hum Reprod Update. 2016 Jan-Feb;22(1):2-22. doi: 10.1093/humupd/dmv034. Epub 2015 Jul 22. Review. — View Citation

Wale PL, Gardner DK. Time-lapse analysis of mouse embryo development in oxygen gradients. Reprod Biomed Online. 2010 Sep;21(3):402-10. doi: 10.1016/j.rbmo.2010.04.028. Epub 2010 Aug 5. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Embryo quality at Day 2 between groups A and B.	Embryo morphology is qualified as the number of blastomeres, degree of cytoplasmic fragmentation, regularity of the cells and presence/absence of multinucleated blastomeres. Day 2 top-quality embryos are defined as 4 regular blastomeres, <20% cytoplasmic fragmentation, no multinucleations.mbryos are defined as 4/8 regular blastomeres, <20% cytoplasmic fragmentation, no multinucleations.	Day 2
Primary	Embryo quality at Day 3 between groups A and B.	Embryo morphology is qualified as the number of blastomeres, degree of cytoplasmic fragmentation, regularity of the cells and presence/absence of multinucleated blastomeres. Day 3 top-quality embryos are defined as 8 regular blastomeres, <20% cytoplasmic fragmentation, no multinucleations.	Day 3
Primary	Embryo quality at blastocyst stage (Day 5) between groups A, B and C.	Blastocyst morphology is assessed according to Gardner and Schoolcraft's classification: degree of blastocele expansion (graded from B1 to B6), inner cell mass and trophectoderm morphology (both graded A, B or C). Day 5 top quality blastocyst are defined as =B4AA/AB/BA.	Day 5
Primary	Embryo quality at blastocyst stage (Day 6) between groups A, B and C.	Blastocyst morphology is assessed according to Gardner and Schoolcraft's classification: degree of blastocele expansion (graded from B1 to B6), inner cell mass and trophectoderm morphology (both graded A, B or C). Day 5 top quality blastocyst are defined as =B4AA/AB/BA.	Day 6
Secondary	Fertilization rate	Percentage of oocytes fertilized per oocyte inseminated, assessed at Day 1	Days 1
Secondary	Early cleavage rate	Percentage of embryos at the 2-cell stage per oocyte fertilized, assessed 25 hours after insemination	25 hours after insemination
Secondary	Useable embryo rate	Percentage of embryos transferred and/or frozen per embryo	Days 2/3; 5/6
Secondary	Implantation rate	Number of gestational sacs with fetal heart beat detected per embryo transferred	4-5 weeks after transfer
Secondary	Clinical pregnancy rate	Percentage of pregnancies diagnosed by ultrasonographic visualization of at least one gestational sac with fetal heart beat per embryo transfer	4-5 weeks after transfer
Secondary	Miscarriage rate		4-5 weeks after transfer