Embryo Culture Under Constant 5% vs Gradient 8%, 5%, 2% Oxygen Concentration

University Medical Centre Maribor

Status: Completed

Conditions: Embryonic Development; Embryo Morphometry; Embryo Morphokinetics

Treatments: Other: Experimental intervention: 8-5-2% oxygen gradient concentration in the incubator

Study type: Interventional

Funder types: Other

Identifiers

NCT05898178

P3-0327

0120-405/2021/4

Details and patient eligibility

About

The purpose of this study is to investigate the development of human embryos in vitro under two different oxygen concentrations; a static 5% during all five days of culture or under an oxygen gradient, starting with 8% from day-0 to day-3, continuing with 5% on day-3 and following with 2% of oxygen from the end of day-3 to day-5.

Full description

Several studies have shown that embryonic morphological parameters improved when the oxygen concentration in embryo culture was reduced from 20% to 5%. Early mammalian embryos developed faster, had shorter cell cycles, a higher blastocyst formation rate and a better integrity of the inner cell mass (ICM) compared to embryos cultured at 20% oxygen concentration.

Recent studies have shown that the oxygen concentration in the female reproductive tract is not static. In the fallopian tubes of higher mammals it is at around 8%, while in the uterus, at the time of embryo implantation, the oxygen concentration is almost anoxic (2%).

Mimicking such physiological conditions that better reflect the in vivo environment in the human reproductive tract is the goal of assisted reproductive technology (ART).

The aim of this study is to assess whether changing the static 5% oxygen during five days of in vitro embryo culture to the gradient of oxygen, starting with 8% from day-0 to day-3, continuing with 5% on day-3 and following with 2% of oxygen from the end of day-3 to day-5, better reflects conditions found within the human reproductive tract and improves embryo developmental characteristics.

Enrollment: 44 patients

Sex: Female

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age of women between 18 and 35 years.
• Body mass index (BMI) between 18 and 30 kg/m².
• Only patients with ICSI procedure (male factor of infertility, excluding azoospermia) and blastocyst culture.
• Patients from first and second ICSI cycle attempt.
• Gonadotropin hormone-releasing hormone (GnRH) antagonist cycles.

Exclusion criteria

• Presence of endometriosis.
• Previous clinical intervention on ovaries.
• Connected endocrine or metabolic diseases.
• Presence of polycystic ovary syndrome.

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

---

44 participants in 2 patient groups

8-5-2% oxygen gradient concentration in the incubator

Experimental group

Description:

A physiological oxygen gradient concentration in the incubator (8-5-2% O2).

Treatment:

Other: Experimental intervention: 8-5-2% oxygen gradient concentration in the incubator

Control (no intervention)

No Intervention group

Description:

Arbitrary cultivation conditions (static 5% 02).