Oocyte competence prediction
The Corona Test measures the potential of an oocyte to develop into a normal healthy child after ICSI. After testing the corona cells of each oocyte after hormone stimulation, the embryo from the oocyte with the highest potential will be transferred into the uterus.
Applying this technology in IVF practice has shown that pregnancy rates have doubled (from 27% to 63%) and live birth increased from 25% to 55% after the transfer of a single embryo on day 3.
Corona Test Principle for IVF/ICSI
The Corona Test is performed on corona cells surrounding the oocytes from a patient. The test is based on the measurement of expression of five specific genes.
Corona cells are isolated from each oocyte and RNA is extracted from the corona cells. cDNA synthesis and real-time PCR is performed using 3 predictive genes and two control genes. PCR results lead to a quantitative ranking for all oocytes.
Corona Test principle for Social Oocyte Freezing
The Corona Test is performed on corona cells from all oocytes from a patient and follows the same molecular testing. The oocytes are ranked, and then grouped in different quality classes.
Results clinical trial
Doubled clinical pregnancy rate for Day 3 fresh SET
Results of a prospective clinical study in Europe showed that in the Corona Test arm with single day-3 embryo transfer, the clinical pregnancy rate increased from 27% to 63% in the first fresh transfer cycle in patients undergoing IVF-ICSI after stimulation with HP-hMG (Figure). In the two control arms patients had either day-3 or day-5 single embryo transfer with morphological scoring only.
The Corona Test was developed from 2008 to 2013 (ref. 1-5). From 2013 to 2018 the test was validated in a prospective match case/control study with 62 patients in the interventional arm. Follow-up study of 100 patients showed the same results (unpublished data).
Increased cumulative pregnancy rate
The Corona Test also significantly increased the cumulative pregnancy rate from 56% to 78% in comparison to day-3 control group when the patient undergoes consecutive cycles.
Increased the live birth rate
The live birth rate increased from 23% to 55% in comparison to day-3 control group.
The Corona Test also significantly increased the clinical pregnancy rate in comparison to day-5 control group (from 43%to 63% in fresh cycle and 65% to 78% in cumulative transfers).
The application of Corona Test is validated for patients with the following criteria:
- Stimulation with HP-hMG hormones (e.g. Menopur) followed by ICSI
- Patient age between 22 to 38 years
- Good ovarian reserve
- Excluding severe male infertility
- Single embryo transfers (fresh or frozen) to avoid twin birth
Corona Test service offered
- DAY 0: Corona-oocyte complex pick-up. Corona cells must be removed for each oocyte by embryologist and individually snap-frozen at -80°C in transport container (dry shipper with N2 or dry ice).
- DAY 1: Samples will be transported to a clinical testing lab nearby which runs the Corona Test
- DAY 2-3: Corona Test (RNA isolation, QPCR and analysis) is done in the clinical testing lab.
- DAY 3: Clinical testing lab will communicate Clinical Report to IVF clinic. Report gives a ranking of all oocytes and specifies which corona-oocyte complex has the best score.
- Embryologist uses this score along with a morphological evaluation to select the best embryo for transfer.
- In case there is no pregnancy from a first transfer, the supernumerary embryos which were vitrified will also be transferred according to their score.
In the future, the Corona Test application will be broadened to other gonadotrophins.
- Wathlet S, Adriaenssens T, Segers I, Verheyen G, Van Landuyt L, Coucke W, Devroey P, Smitz J. Pregnancy prediction in single embryo transfer cycles after ICSI using QPCR: validation in oocytes from the same cohort. PLoS One. 2013;8(4)
- Wathlet S, Adriaenssens T, Segers I, Verheyen G, Janssens R, Coucke W, Devroey P, Smitz J. New candidate genes to predict pregnancy outcome in single embryo transfer cycles when using cumulus cell gene expression. Fertil Steril. 2012 Aug;98(2)
- Wathlet S, Adriaenssens T, Segers I, Verheyen G, Van de Velde H, Coucke W, Ron El R, Devroey P, Smitz J. Cumulus cell gene expression predicts better cleavage-stage embryo or blastocyst development and pregnancy for ICSI patients. Hum Reprod. 2011 May;26(5)
- Adriaenssens T, Segers I, Wathlet S, Smitz J. The cumulus cell gene expression profile of oocytes with different nuclear maturity and potential for blastocyst formation. J Assist Reprod Genet. 2011 Jan;28(1):31-40
- Adriaenssens T, Wathlet S, Segers I, Verheyen G, De Vos A, Van der Elst J, Coucke W, Devroey P, Smitz J. Cumulus cell gene expression is associated with oocyte developmental quality and influenced by patient and treatment characteristics. Hum Reprod. 2010 May;25(5)
- Adriaenssens T, Van Vaerenbergh I, Coucke W, Segers I, Verheyen G, Anckaert E, De Vos M, Smitz J. Cumulus-corona gene expression analysis combined with morphological embryo scoring in single embryo transfer cycles increases live birth after fresh transfer and decreases time to pregnancy. J Assist Reprod Genet. 2019 Jan 9.. [Epub ahead of print]