en <p>Background: The identification of c-type natriuretic peptide (CNP) as a key upstream regulator of cyclic GMP (cGMP) levels has paved the way for innova-tive in vitro maturation (IVM) techniques, the so-called biphasic CAPA-IVM (capacitation IVM) approach. This method uses CNP to prevent early meiosis progression and has demonstrated enhanced oocyte maturation rates. This report highlights the successful use of the CAPA-IVM method in Indonesia.&nbsp;<br /> Case Presentation: Immature cumulus-oocyte complexes (COCs) were successfully retrieved from an infertile woman aged 37 years without prior ovarian stimulation. The obtained COCs were incubated in CAPA medium for 24 <em>hr</em> and then transferred to a maturation medium containing amphiregulin, insulin, human serum albumin, and recombinant FSH. After 30 <em>hr</em>, all immature oocytes reached the metaphase II (MII) stage, as evidenced by the first polar body extrusion and confirmed through spindle formation.&nbsp;<br /> Conclusion: CAPA-IVM system enabled all retrieved immature oocytes to reach the MII stage without prior ovarian stimulation. This finding supports its feasibility as a simplified IVF approach with the potential to reduce treatment costs, particularly in resource-limited settings. However, further clinical evalua-tion is required to confirm its effectiveness.</p> C-type oocytes, In vitro fertilization, In vitro oocyte maturation, Natriuretic peptide 70 75 https://www.jri.ir/article/140300 /documents/fullpaper/en/140300.pdf AndrewKanMorula IVF Jakarta Clinic, Jakarta, Indonesia123002NiningHandayanIRSI Research and Training Centre, Jakarta, Indonesia122713ArifSofyan AzizMorula IVF Jakarta Clinic, Jakarta, Indonesia123004PitraRahmawatiMorula IVF Jakarta Clinic, Jakarta, Indonesia122788AriefBoedionoFaculty of Medicine, IPB University, Bogor, West Bengal, Indonesia62061IvanSiniFaculty of Medicine, IPB University, Bogor, West Java, Indonesiaivan.sini@apps.ipb.ac.id123007