Enlightenment about the new Architect-i2000 estradiol (Abbott Laboratories) immunoassay during in vitro fertilization

We assessed a new estradiol (E2) immunoassay on the Architect-i2000 (Abbott Laboratories) for monitoring ovulation stimulation for IVF-ET and re-establishing clinical cut-off points. The method has been modified to improve E2 measurements especially at normal and low concentrations.

E2 was determined for 552 samples, from 83 women, presenting normal follicular status and undergoing 100 cycles of IVF treatment. We assessed the value of this assay for down-regulation of E2 concentration limit using gonadoliberin-releasing hormone agonist (GnRHa), and monitoring of the ovarian hyperstimulation, expected range of E2 per mature follicle prior to the administration of exogenous hCG and day 3 concentration limit. We compared results with our routine method (E2-6II Advia-Centaur; Siemens-Diagnostics) for which decision-making values were known.

Considering E2 concentrations obtained with the new Architect-i2000 assay for patients treated with GnRHa for 2 weeks, the cutoff-point for ovarian down-regulation should be set down at 110 pmol/L to maintain 100% of sensitivity. Considering day 3 concentration limit determination, results were not significantly different from those obtained with our routine method. The mean E2 values per mature follicle fell into the range generally expected.

E2 determination with the new E2 Architect-i2000 assay could be used to monitor ovulation, in patients undergoing IVF-ET, in combination with transvaginal ultrasound.