A Multicenter Prospective Randomized Controlled Clinical Trial Comparing Constant (5%) Versus Sequential (5%-2%) Oxygen Concentration Embryo Culture Protocols in Assisted Reproductive Technology

Not Applicable

Recruiting

• Conditions: Blastocyst IVF; Fertility Issues; Embryo Culture

• Registration Number: NCT07050537
• Lead Sponsor: The First Affiliated Hospital with Nanjing Medical University

Brief Summary

To evaluate whether there were significant differences in the effects of constant (5%) versus sequential (5%-2%) oxygen concentration protocols in embryo culture on term live birth rates.

This study will be conducted in five centers including the Clinical Center of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical Universit. 980 women who wish to undergo blastocyst transplantation will be included in the study.

The study data will be analyzed statistically.

Detailed Description

While blastocyst transfer has been shown to improve live birth rates, concerns exist regarding potential telomere shortening in offspring, which is associated with premature aging and various health issues. Our previous study further explores the role of oxygen tension in telomere length regulation, identifying hypoxia-inducible factor 1α (Hif1α) degradation as a key factor. Based on these findings, the study proposes a prospective, randomized controlled clinical trial comparing constant (5%) versus sequential (5%-2%) oxygen concentration protocols in embryo culture to assess their impact on term live birth rates and offspring telomere length.

This study will be conducted in five centers including the Clinical Center of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical Universit. 980 women who wish to undergo blastocyst transplantation will be included in the study.

Female infertile patients who consent to blastocyst transfer will be considered for inclusion in the study. Patients will be randomly assigned to a constant (5%) or sequential (5%-2%) oxygen concentration protocols in embryo culture. This study will record live birth rates, perinatal and perinatal complications, and offspring health status of women in both groups of embryo culture regimens to assess the effects of different embryo culture regimens on term live birth rates and offspring health.

Study Timeline

• Study Start: 2025-03-01
• Status Verified: 2025-06
• Study First Submitted: 2025-06-26
• Study First Submitted QC: 2025-06-26
• Last Update Submitted: 2025-06-26
• Study First Posted: 2025-07-03
• Last Update Posted: 2025-07-03
• Primary Completion: 2027-03-31
• Study Completion: 2027-08-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 980

Inclusion Criteria

1. Female: age ≥20 and ≤40 years, male: age ≥20 and ≤50 years;
2. Proposed 1st or 2nd cycle of IVF or ICSI fertilization;
3. ≥ 4 transferable embryos at oocyte stage.

Exclusion Criteria

1. Diagnosis of abnormal uterine cavity morphology (confirmed by 3D ultrasound or hysteroscopy), including uterine malformations (mediastinal uterus, unicornuate uterus, bicornuate uterus), submucosal uterine fibroids, or uterine adhesions;
2. Patients who are proposed to undergo IVM;
3. Patients who are proposed to undergo PGD/ PGS;
4. Patients with untreated severe hydrosalpinx (confirmed by ultrasound or HSG);
5. Patients with a history of recurrent miscarriage (2 or more previous pregnancy losses, excluding biochemical pregnancies);
6. Patients who plan to freeze whole embryos and are unable to complete a single embryo transfer within six months;
7. Patients with contraindications to assisted reproductive technology and pregnancy, or suffering from diseases that have a definite effect on pregnancy: including uncontrolled hypertension, heart disease with definite symptoms, uncontrolled diabetes, undefined diagnosis of liver or kidney disease or liver or kidney insufficiency, severe anemia, history of previous venous thrombosis, pulmonary embolism or cerebrovascular events, history of malignant tumors, suspected malignant tumors, and undiagnosed abnormal uterine bleeding.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Term live births	3 years	Full-term healthy live birth rate for all patients

Secondary Outcome Measures

Name	Time	Method
Implantation rate	3 years	Implantation rate per transfer cycle
Offspring health (Peripheral blood telomere length)	3 years	Peripheral blood telomere length in all live-born offspring
Clinical pregnancy rate	3 years	Clinical pregnancy rate for all transfer cycles
Ectopic pregnancy rate	3 years	Ectopic pregnancy rate for all transfer cycles
Miscarriage rate	3 years	Miscarriage rate per transfer cycle

Trial Locations

Locations (5)

The Third Affiliated Hospital of Zhengzhou University; 🇨🇳 Zhengzhou, Henan, China

Changzhou Maternal And Child Health Care Hospital; 🇨🇳 Changzhou, Jiangsu, China

Nanjing Women and Children's Healthcare Hospital; 🇨🇳 Nanjing, Jiangsu, China

Reproductive Medicine of First Affiliated Hospital with Nanjing Medical University; 🇨🇳 Nanjing, Jiangsu, China

Suzhou Municipal Hospital; 🇨🇳 Suzhou, Jiangsu, China