Received February 18, 2026
Accepted March 02, 2026

Background: Excess body weight is associated with subfertility and delayed conception, yet its effect on in vitro fertilization (IVF) outcomes in women with preserved ovarian reserve remains uncertain. This study examined the impact of overweight and obesity on IVF outcomes. Methods: This retrospective cohort study included 159 infertile women aged 20–35 years who underwent IVF between December 2022 and May 2025. All participants had adequate ovarian reserve (anti-Müllerian hormone ≥1 ng/mL and antral follicle count ≥5) and infertility due to polycystic ovary syndrome, mild male factor, tubal factor, or unexplained causes. Based on body mass index (BMI), women were classified as normal weight, overweight, or obese. All patients received a standardized long agonist ovarian stimulation protocol. Study outcomes included gonadotropin dose, stimulation duration, number and quality of oocytes and embryos, fertilization rates, clinical pregnancy rates per initiated cycle and per embryo transfer, and cycle cancellation rates. Multivariable regression analyses adjusted for age, AMH, and AFC were performed. Results: Baseline characteristics were comparable among groups. Obese women required significantly higher gonadotropin doses and exhibited poorer ovarian response, with fewer retrieved and mature oocytes, reduced high-quality embryo yield, and lower fertilization rates. Clinical pregnancy rates declined with increasing BMI, while cycle cancellation rates were significantly higher in obese patients. Overweight status showed no independent adverse effect after adjustment. Conclusion: In women with preserved ovarian reserve, obesity independently impairs ovarian response, embryo development, and IVF success, whereas overweight does not. Weight optimization before IVF may improve treatment outcomes.