Received October 10, 2022
Accepted May 18, 2023

Objective: Evaluate the impact of body mass index associated with advanced maternal age on outcomes. Methods: A retrospective and observational study that included 808 in vitro fertilization cycles and evaluated: age, weight, height, number of oocytes and mature oocytes, number of embryos and transferred embryos, fertilization and clinical pregnancy rates. Four categories of body mass index: underweight, adequate weight, overweight and obesity. Age was categorized into 4 ranges: 35-37; 38-40; 41-42 and over 42 years old. The means and rates were calculated and compared between different ages and body mass index groups. Results: For the fresh group, that women who achieved clinical pregnancy had a lower mean age than those who did not become pregnant, with the higher the pregnancy rate the lower the age (p<0.0001). After logistic regression analysis for data associated with clinical pregnancy in the fresh group, the number of transferred embryos remained higher in the overweight category (p=0.0001). Overweight and obese women had a significantly higher rate of mature oocytes when compared with adequate weight (p=0.015). Analysis using the ROC curve indicated an area under the curve of 60% (p=0.002) for the group fresh. Conclusion: The adverse effect of high BMI on clinical pregnancy rates is greater in women under 35 years compared to older women and age has a higher impact on live birth rate rather than BMI when the analysis is performed on older women, with the impact of BMI on the probability of having a live birth depending on maternal age.