This study is a preliminary, prospective, randomized, controlled clinical trial designed to evaluate the safety and feasibility of supplementing in vitro maturation (IVM) media with autologous exosomes in women with diminished ovarian reserve undergoing assisted reproductive technology. The purpose of the study is to determine whether autologous exosomes can support the meiotic progression of immature metaphase I oocytes during a 24-36 hour culture period and to establish whether the intervention is safe, biologically feasible, and suitable for further clinical evaluation. Mature oocytes obtained after culture are fertilized using intracytoplasmic sperm injection, and resulting embryos are cryopreserved for future transfer in a subsequent phase of the research. No embryo transfer is performed during this preliminary phase.

Women with diminished ovarian reserve frequently present a high proportion of immature oocytes after controlled ovarian stimulation. These immature oocytes cannot be fertilized and limit the number of mature oocytes available for assisted reproductive procedures. Oocyte maturation is regulated by a coordinated set of intracellular signaling pathways, intercellular communication with granulosa cells, and molecular mechanisms that maintain meiotic arrest and trigger meiotic resumption. Emerging scientific evidence indicates that extracellular vesicles, including autologous exosomes, may play a role in supporting oocyte maturation through the transfer of bioactive molecules.

This preliminary clinical study was designed to evaluate the safety and feasibility of using autologous exosomes as a supplement to conventional in vitro maturation (IVM) media. The study population includes women aged 38-46 years with documented diminished ovarian reserve who declined oocyte donation and who met predefined clinical, endocrine, and reproductive criteria. All participants provided written informed consent. The study was conducted in accordance with national regulations and international ethical principles for research involving human subjects.

Eligible participants undergo controlled ovarian stimulation using recombinant follicle-stimulating hormone, human menopausal gonadotropin, and an antagonist protocol, followed by human chorionic gonadotropin triggering and oocyte retrieval. Only metaphase I oocytes are included in the intervention portion of the study. After identification, metaphase I oocytes are randomly assigned to one of two groups using a simple computer-generated randomization method.

In the control group, oocytes are cultured in conventional in vitro maturation medium. In the experimental group, oocytes are cultured in the same medium supplemented with a standardized quantity of autologous exosomes isolated from each participant according to the study protocol. Culture duration ranges from 24 to 36 hours. After the culture period, oocytes reaching metaphase II are fertilized via intracytoplasmic sperm injection to standardize the fertilization procedure. Embryos developing after fertilization are cultured under standardized laboratory conditions, evaluated according to established morphological criteria, and cryopreserved for use in a future phase of the research. Embryo transfer is not performed during this preliminary phase.

The primary objective of the study is to assess whether autologous exosome supplementation is feasible and safe for use in IVM culture systems. Secondary objectives include documenting the procedures involved in oocyte handling, fertilization, and embryo cryopreservation to support future phases of the study. The study does not include analysis of results or clinical outcomes, as no outcomes are permitted to be reported in the Protocol Section of the ClinicalTrials.gov record. A subsequent phase of the research will evaluate implantation, clinical pregnancy, and live birth after transfer of cryopreserved embryos generated in this protocol.

Inclusion Criteria:

• Women with primary or secondary infertility associated with diminished ovarian reserve, defined by ultrasound findings and laboratory parameters (FSH > 10 mIU/mL and estradiol < 60 pg/mL).
• Serum anti-Müllerian hormone (AMH) concentration < 1 ng/mL.
• Antral follicle count < 3-6 follicles per ovary.
• Anatomical preservation of both ovaries.
• Body mass index (BMI) between 24.5 and 30 kg/m².
• Absence of active oncological pathologies or connective tissue diseases (collagenopathies).
• No history of clinically relevant hematological disorders.
• Adequate serum levels of vitamins essential for reproductive function, including vitamin D, B-complex, and vitamin C.
• Last live birth within ≤ 10 years prior to study initiation.
• Normal thyroid function (TSH and free thyroid hormones within range).
• Absence of antiphospholipid antibody syndrome.
• Male partner with semen parameters within normal limits, according to the World Health Organization (WHO) criteria, 2010 (5th edition) and 2021 (6th edition).
• Signed informed consent for participation in the study.

Exclusion Criteria:

• • Patients without a diagnosis of infertility.

  • Women without documented diminished ovarian reserve.
  • Serum anti-Müllerian hormone (AMH) concentration > 1 ng/mL.
  • Antral follicle count > 3-6 follicles per ovary.
  • Absence of one or both ovaries.
  • Body mass index (BMI) > 30 kg/m².
  • Presence of active oncological pathologies or connective tissue diseases (collagenopathies).
  • History of clinically relevant hematological disorders.
  • Deficient or altered serum levels of vitamins essential for reproductive function (vitamin D, B-complex, and vitamin C).
  • Last live birth > 10 years prior to study initiation.
  • Altered thyroid function (TSH or free thyroid hormones out of range).
  • History of antiphospholipid antibody syndrome.
  • Male partner with abnormal semen parameters according to the World Health Organization (WHO) criteria, 2010 (5th edition) and 2021 (6th edition).
  • Refusal to sign informed consent for study participation.

Not but the individual participant data (IPD) from this study will be available to other qualified researchers upon reasonable request. Data sharing will be granted after a formal email request specifying the investigator's identity, institutional affiliation, and research objective. Access will be provided only for scientifically justified purposes, in compliance with confidentiality agreements and ethical standards protecting participant privacy.