The adverse effect of overweight in assisted reproduction treatment outcomes

OBJECTIVE To assess Body Mass Index (BMI) effects on the results obtained from ICSI cycles. METHODS We studied 266 ICSI cycles performed between January 2014 and December 2016. The patients were grouped according to their BMI in: Normal (18.5-24.9), Overweight (25.0-29.9) and Obese (>30). We compared the following variables between the groups: number of antral follicles, ovarian stimulation length, gonadotropin dose used, maximum estradiol level, follicles developed/antral follicles, retrieved oocytes/developed follicles and mature/retrieved oocytes, normal fertilization rate, embryo achieved/normal fertilized oocytes, clinical pregnancy and implantation rates. We used the Kruskal-Wallis and the Chi square tests. p<0.05 was considered significant. RESULTS Normal, Overweight and Obese patients presented comparable values for number of antral follicles (11.6±5.4, 12.5±5.5, 12.2±5.7), ovarian stimulation length (7.5±1.4, 7.6±1.1, 7.8±1.3) and gonadotropin dose used (2043±489, 1940±536, 2109±605). Obese patients had lower values of estradiol (1560±610, 1511±635, 1190±466; p=0.018), developed follicles (81%, 76%, 70%; p<0.0001), and retrieved oocytes (91%, 90%, 84%; p=0.0017); and not significantly lower values of mature oocytes (82%, 82%, 77%; p=0.26). The groups had comparable fertilization rates (72%, 73%, 69%) and embryo achieved rates (67%, 63%, 72%). The normal group had higher, but not significantly higher pregnancy and implantation rates (43%, 40%, 38%, p=0.53; and 33%, 26%, 23%; p=0.11), and significantly higher ongoing pregnancy rates (37%, 33%, 33%, p=0.042). CONCLUSION Increased BMI patients had impaired ovarian response and lower pregnancy rates in ICSI cycles.