Abstract Study question What is the cumulative live birth rate in biphasic (capacitation) in vitro maturation (CAPA-IVM) cycles in women with predicted excessive response? Summary answer The cumulative live birth rate achieved after CAPA-IVM in women with predicted excessive response was 37.8%. What is known already In vitro maturation (IVM) is an alternative infertility treatment for women at high risk of complications during conventional in vitro fertilisation with ovarian stimulation. There is debate about the merits of a newer biphasic approach (capacitation [CAPA]-IVM) versus standard IVM. At centres where it is used, CAPA-IVM has increased the maturation rate, and therefore the number of embryos available for transfer. However, there is a lack of data from large numbers of CAPA-IVM cycles, especially cumulative outcomes. Study design, size, duration This analysis included data from 1,563 individuals who underwent CAPA-IVM at a tertiary IVF center in Ho Chi Minh City, Vietnam from January 2016 to December 2023. Participants/materials, setting, methods All CAPA-IVM cycles in women with predicted excessive response (polycystic ovary syndrome or high antral follicle count) were included. Mean age was 29.6±3.5 years. Median duration of infertility was 3.3±2.5 years. CAPA-IVM was the first assisted reproductive technology in 90.5% of participants. Cumulative live birth rate was defined as the number of live births after using all embryos generated from a CAPA-IVM cycle. Main results and the role of chance Cumulative rates of clinical pregnancy, ongoing pregnancy and live birth were 54.9%, 44.4% and 37.8%, respectively. The median proportion of mature oocytes per cumulus-oocyte complex was 61.3% (IQR 50.0–73.3) and the median proportion of fertilized oocytes per cumulus-oocyte complex was 72.2% (IQR 55.6-85.7). The median total number of day-3 embryos per patient was 4.0 [IQR 3.0–7.0] and the total number of good day-3 embryos per patient was 3.0 [IQR 2.0–5.0]. The proportion of patients with no embryo was 5.2%. The number of frozen embryo transfer cycles was 1 (53.6% of patients), 2 (24.9%), 3 (7.0%), 4 (0.8%) or 5 (0.3%); 7.9% of patients had not undergone transfer of day-3 embryos at the time of analysis. Median [IQR] number of embryos and good embryos transferred was 2.0 [2.0–4.0] and 2.0 [1.0–2.0], respectively. No case of ovarian hyperstimulation syndrome recorded. Limitations, reasons for caution The characteristics of the study population (relatively young, lean women from Vietnam with predicted excessive response to ovarian stimulation) limit the external generalisability of the findings. Wider implications of the findings The cumulative live birth rate from all CAPA-IVM cycles performed in women with predicted excessive response at our centre was comparable to that of IVF. CAPA-IVM could be an alternative for this selected group of patients to avoid ovarian hyperstimulation. Trial registration number not applicable