EStradiol and PRogesterone in In vitro ferTilization (ESPRIT): a multicenter study evaluating third- versus...

Area of Science:

• Reproductive endocrinology
• Clinical chemistry
• Infertility diagnostics

Background:

• Accurate measurement of estradiol (E2) and progesterone is crucial for monitoring ovarian stimulation in assisted reproductive technologies.
• Advancements in immunoassay technology, such as third-generation (Gen III) Elecsys® assays, aim to improve diagnostic accuracy compared to second-generation (Gen II) assays.

Purpose of the Study:

• To compare E2 and progesterone levels measured by Elecsys® Gen III and Gen II immunoassays during ovarian stimulation.
• To evaluate the correlation and agreement between the two assay generations and with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for progesterone.

Main Methods:

• Retrospective analysis of serum samples from 230 women undergoing ovarian stimulation at European fertility clinics.
• Measurement of E2 and progesterone using Elecsys® Gen III and Gen II immunoassays.
• Progesterone measurement on the day of ovulation triggering by LC-MS/MS for validation.

Main Results:

• High correlation between Gen III and Gen II assays for both E2 (r=0.99) and progesterone (r=0.89).
• Gen III assay results were consistently lower than Gen II assays, with mean differences of -15.0% for E2 and -27.9% for progesterone on the day of triggering.
• Progesterone measurements by LC-MS/MS correlated better with Gen III (r=0.98) than Gen II (r=0.90) assays, with significantly lower mean relative differences for Gen III (14.6%) versus Gen II (62.8%).

Conclusions:

• Elecsys® Gen II and Gen III immunoassays demonstrate high correlation for E2 and progesterone during ovarian stimulation.
• Observed lower results with the Gen III assay compared to Gen II, particularly for progesterone, may hold clinical relevance for treatment adjustments.