Body fat distribution influences ART outcomes

Abstract

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.

摘要

体重指数（BMI）是评估肥胖的常用方法, 但它不能区分瘦组织和脂肪也不能区分脂肪的分布。提出了其他方法来评估肥胖, 如腰围、臀围、腰臀比以及通过生物电阻抗（BF%）分析体脂, 但它们没有用来评估辅助生殖的结局。本研究旨在确定体成分和脂肪组织分布是否在ART结局上优于BMI。通过对788名接受控制性卵巢过度刺激和体外受精技术的女性进行五次人体测量, 进行了分析。体脂的增加, 不依赖于测量方法, 与较差的生殖结局有关。然而, 一个奇怪的发现是：发育正常, 腰围小于80cm的女性相比于发育正常腰围大于80cm的女性妊娠率高2倍（38.9% vs.14.3%）（p=.002）。此外, 腰臀比大于0.85的肥胖女性的ART结局相比于腰臀比小于0.85的女性更差, 考虑到获卵率、成熟卵母细胞和受精率。综上所述, 可以观察到体脂分布, 尤其是腰围比BMI更能预测ART的预后。

The Chinese abstracts are translated by Prof. Dr. Xiangyan Ruan and her team: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China.

Keywords:

• Anthropometric indicator
• body composition
• infertility
• waist circumference
• gestation

Acknowledgments

The authors would like to thank all the patients and Instituto Ideia Fértil nurses, medical doctors and embryologists that contributed to this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector. CAPES scholarship (CAPES/PROSUP no. 1204841).