Figure 2.

Model of steroid hormones and metabolites within the maternal-placental-fetal unit. Bold text indicates metabolites that were detected from maternal plasma by Metabolon; black and bold indicates metabolites that were detected but not different among groups; red indicates metabolites that were increased in both IVF and infertility groups when compared with the spontaneous group; green indicates metabolites that were downregulated in the infertility group compared with the spontaneous group; *metabolites that were increased only in the IVF group compared with spontaneous group; **increased pregnenolone sulfate (pregnenolone metabolite) in fresh IVF group compared with spontaneous group that is derived directly from pregnenolone. DHEA, dehydroepiandrosterone; DHEA-S, dehydroepiandrosterone sulfate.