Baseline non-fasting serum leptin concentration to body mass index ratio is predictive of IVF outcomes

BACKGROUND: The present study was designed to determine whether circulating leptin concentrations and/ or body mass index (BMI) in women undergoing IV F are predictive of outcomes. METHODS: IVF cycle outcomes, e.g. fertilizati on, embryo development, implantation, pregnancy, were analysed relative to baseline (i.e. day gonadotrophin stimulation was initiated) non-fasting ser um leptin concentrations and BMI. RESULTS: Serum leptin concentrations corr elated with BMI (r = 0.739, P < 0.0001) as expected. Multiple logistic regr ession analyses showed correlation between serum leptin and pregnancy succe ss (likelihood ratio = 5.198, P < 0.05), but there was no association betwe en pregnancy and BMI. However, the serum leptin to BMI ratio was more stron gly correlated (likelihood ratio = 7.258, P < 0.01) with pregnancy success than was leptin alone. Moreover, women with a low leptin:BMI ratio (<less t han or equal to>0.3) had significantly more superior quality embryos on day 3 post-retrieval (2.5 versus 1.4, P < 0.05, Kruskal-Wallis) and a greater implantation rate (26.7 versus 13.2%, P < 0.025, chi (2)) than women with a high leptin:BMI ratio (greater than or equal to0.7). CONCLUSIONS: The lept in:BMI ratio appears to be highly predictive of IVF success. Elevated lepti n concentrations, particularly relative to BMI, may negatively impact ferti lity by assisted reproduction, possibly through direct ovarian actions resu lting in impaired oocyte quality and/or early embryo development.