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.