Spuriously elevated serum estradiol concentrations measured by an automated immunoassay rarely cause unnecessary cancellation of in vitro fertilization cycles

If a patient on a long controlled ovarian hyperstimulation IVF protocol still has high serum E2 levels after 2 to 3 weeks of down-regulation, and obvious reasons for this (pregnancy, E2 producing ovarian cysts, noncompliance of the patient) are excluded, E2 immunoassay interference should be excluded to avoid unnecessary cancellation of the IVF cycle.