EFFECT OF ABDOMINAL FAT ON INTRACYTOPLASMIC SPERM INJECTION CYCLES: PRELIMINARY RESULTS

Abstract

This study aimed at evaluating whether subcutaneous and pre-peritoneal abdominal fat as well as follicular fluid leptin (FFL) predict intracytoplasmic sperm injection (ICSI) outcomes in women without polycystic ovary syndrome (PCOS). Prospective cohort study (NCT03778684) in an University-affiliated Assisted Conception Center. University IRB approved the study. Infertile non-PCOS women indicated for ICSI were considered for enrollment after consent. Included women were grouped based on their waist circumference (WC) into women with central obesity (WC ≥ 80 cm; COB group) and without (WC< 80 cm; Non-COB group). At baseline evaluation, women underwent assessment of obesity using different measures and assessment of homeostasis-model for insulin resistance (HOMA-IR). Obesity measures included body mass index (BMI), visceral adiposity index (VAI), and the novel body fat index (BFI). BFI was calculated by multiplying pre-peritoneal and subcutaneous fat (in mm) and divided by height (in cm). FFL was measured from pooled follicular fluid of ≥ 17 mm follicles, containing cumulus oocyte complex. Our primary endpoint was ongoing pregnancy rate (OPR). Comparisons between groups were evaluated utilizing the independent t , Wilcoxon rank sum, and chi-square tests as appropriate. Logistic regression model, receiver operating characteristic (ROC) curve and correlation coefficient (r) were also utilized. We planned a sample size of 168 women. Recruitment was temporarily suspended due to COVID-19 pandemic. Recruitment will continue, once IVF procedures are resumed based on our governmental policy Of 340 women screened, 72 eligible women were included in this preliminary analysis; 40 in COB group and 32 in Non-COB group. Both groups were comparable in age, AMH, duration of infertility, IVF indication, HOMA-IR, cycle characteristics and FFL concentrations. Women in COB group were more likely to have higher BMI (mean±SD;30.5±3.9vs25.3±2.8 p < 0.005), BFI (median(IQR),1.8(1.8) vs0.73(0.2), p<0.005), and VAI ( median(IQR),1.9 (1.06) vs 1.2 (0.65), p<0.001). Both groups showed comparable maturation index (73.8%vs77.9%), fertilization rate (71.2%vs72.1%), and OPR (37.5% vs 43.8%). In the correlation analysis, central obesity was more likely to be due to subcutaneous (r=0.8, p<0.001) rather than preperitoneal fat (r=0.4, p<0.001). None of the obesity measures were correlated with either FFL or OPR. No significant correlation was found between FFL levels and number of oocytes retrieved, maturation and fertilization indices, or rate of good-quality embryos. In ROC analysis, comparable trend was observed among BMI, BFI, VAI, and FFL for predictability of ongoing pregnancy (AUC: 0.48, 0.53, 0.50, and 0.48, respectively). None of these variables was predictor for OPR in the multivariable logistic regression. The only predictors were peak estradiol (OR:1.2,CI:1.1-1.3, p< 0.05) and number of mature retrieved oocytes (OR:0.08,CI:0.67-0.92,p<0.004). Based on this analysis, we could not find evidence that FFL and abdominal fat thickness affect ICSI outcomes.