Day 3 embryo metabolomics in the spent culture media is altered in obese women undergoing IVF

Abstract

To determine whether the metabolomic profile in the spent culture media of day-3 embryos is different in obese and normoweight women undergoing IVF, also considering the association with polycystic ovary syndrome (PCOS). Prospective case-control analysis. Twenty-eight young (< 38 years) women with normal uterus and ovaries, and absence of endometriosis, hydrosalpinx or smoking habit were recruited. Patients underwent their first IVF attempt due to idiopathic infertility, tubal factor, or failed intrauterine insemination, presenting a normoweight male partner without severe sperm factor. Group A included ovulatory obese (body mass index >30 kg/m2) women (n =12); group B included obese women with PCOS (Rotterdam criteria) (n =4); group C (control) included normoweight (20-24.9 kg/m2) ovulatory oocyte donors (n =12). Exclusion criteria were: <5 or >20 oocytes retrieved; >3.000 pg/ml or >20% fall in estradiol concentration, or >1 ng/ml of progesterone concentration on the day of hCG administration; or <2 ongoing embryos in day 3. A GnRH antagonist protocol using rFSH and hCG triggering was employed. Culture spent media were taken (50 μl) from two embryos of each cohort (with similar morphology) in day 3, analyzing a total of 56 embryos. Samples were centrifuged, frozen (-80ºC) and stored until the analysis was performed comparing the global metabolomic profile of the three groups by ultrahigh performance liquid chromatography coupled to mass spectrometry. The untargeted metabolic profiling analysis of embryo-spent culture media from controls, obese-PCOS and obese-non-PCOS women revealed a different metabolomic profile. Principal component and Partial Least Squares Discriminant Analysis resulted in a clear separation of the three types of samples when a total of 600 metabolites were considered. A good model of prediction was obtained using the 160 most consistent metabolites. This model was able to predict the origin of the sample with 13% and 10% of false negatives and positives, respectively. The metabolic profile in the spent culture media of day-3 embryos is different in normoweight and obese women with a higher deviation when PCOS is associated.