Body fat distribution influences ART outcomes

Body mass index (BMI) is the widely used method to evaluate obesity, but it cannot differentiate lean from fat mass neither mass distribution. Other methods have been proposed for this evaluation, as waist and hip circumferences (WC, HC) and ratio (WHR) and body fat analysis by bioimpedance (BF%), but they have not been applied to evaluate assisted reproduction (ART) outcomes. The present study aims at determining whether body composition and adipose tissue distribution are better than BMI on ART outcomes. Analysis was performed through five anthropometric measurements of 788 women submitted to controlled ovarian hyperstimulation and in vitro fertilization techniques. The increase of body fat, independently of the measurement method, was associated to worse reproductive results. However, a surprising finding was that eutrophic women with WC lower than 80 cm showed gestation rates two times superior (38.9% versus 14.3%) when compared to eutrophic women with WC larger than 80 cm (p = .002). Furthermore, obese women with WHR higher than 0.85 showed worse ART results, considering oocytes retrieved, mature oocytes and fertilization when compared to those with WHR lower than 0.85. As a conclusion, it was observed that the body fat distribution, especially WC, was more relevant than BMI to predict ART outcomes.