Abstract: Objective To find the relationship between phthalates (PAEs) metabolite concentrations and body mass index (BMI) in infertile patients. Methods From December 2018 to January 2021, 120 infertile patients were selected from the Reproductive Medicine Centre of the 988^th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army and the Reproductive Medicine Centre of the Henan Provincial People's Hospital, while 60 patients with no history of infertility and normal weight were selected from the Medical Check-up Centre as the normal group. According to BMI index, the infertility patients were divided into the control group (BMI＜28 kg/m²), obesity group (obesity, BMI ≥28 kg/m²).The obesity group was divided into BHI (BMI≥32 kg/m²) and BH2 (BMI≥28 kg/m², ＜32 kg/m²). The basic information of each group was collected. Serum level of PAEs metabolites diethyl phthalate (DEP), dibutyl phthalate (DBP) and diisooctyl phthalate (DEHP) was detected using liquid chromatography/mass spectrometry (HPLC). The relationship between PAEs metabolite concentration and body mass index (BMI) were analyzed by Spearman′s analysis. Results The serum level of DEP, DBP and DEHP was significantly higher in obese group than in the control group (P＜0.05). The serum level of DEP, DBP and DEHP was significantly higher in the control group than in the normal group (P＜0.05); The metabolites level of PAEs was higher in patients with BHI than in the patients with BH2 (P＜0.05).Spearman's analysis showed that the BMI of the patients in the obese group of infertility was positively correlated with DEP, DBP and DEHP content (P＜0.05). Conclusions Obesity and PAEs metabolite concentration in infertility patients are related, the higher the degree of obesity, the higher the content of related metabolites.

Key words: infertility, phthalic acid esters(PAEs), body mass index(BMI), high performance liquid chromatography (HPLC)