P-780 Ten years electronic witnessing in the IVF laboratory
Authors: Sterckx J , Wouters K , Mateizel I , Janssens R , Tournaye H , Verheyen G , De Munck N 
Published: June 2022

Study question

What did we learn after 10 years of electronic witnessing?

Summary answer

Only when applied correctly, electronic witnessing can prevent sample mix-up.

What is known already

In the early days of IVF, manual double witnessing was used to reduce the misidentification of gametes for insemination. However, risk for human errors due to fatigue, automatism, distraction or work load make this a mistake-prone approach. Hence, there is increasing interest in using electronic witnessing systems for patient and sample identification. Although not always mandatory, such systems have been implemented in many fertility laboratories to avoid identification errors. A mismatch is generated when non-matching samples are simultaneously present in a single workstation. Yet, when the system is incorrectly used, corrective intervention by an administrator (administrator assign) may be required.

Study design, size, duration

This evaluation investigates the mismatch (MM) rate and administrator assigns (AA) over a 10-year period (March 2011- December 2021) with the use of RI Witness (RIW) (CooperSurgical). Radio frequency identification tags (RFID) were used for patient and sample identification. Conventional IVF and ICSI cycles, and frozen embryo cycles (FET) were included since 10 years, IUI cycles since 8 years.

Participants/materials, setting, methods

The total number of tags and witness points (WP) were recorded. Witness points represent all the actions in RIW that have been performed during the entire process. MM and AA were collected and stratified by procedure (sperm preparation, oocyte retrieval, IVF/ICSI, (embryo)biopsy, vitrification/warming, embryo transfer, medium changeover and IUI). Critical MM (such as mis-labeling or non-matching samples within one work area) and critical AA (such as non-RIW-identified samples and unconfirmed WP) were selected.

Main results and the role of chance

A total of 109,655 cycles were included: 53,023 IVF/ICSI, 36,347 FET, and 20,285 IUI cycles. The 724,096 used tags, led to a total of 849,650 WP. The overall MM rate per WP was 0.25% (2,132/849,650), 1.9% per cycle, of which 144 critical mismatches occurred in the different procedures: sperm preparation: 66, oocyte retrieval: 5, IVF/ICSI: 33, (embryo)biopsy: 1, vitrification/warming: 26, embryo transfer: 8, medium changeover: 3 and IUI: 2. The mean critical MM rate per WP per year was 0.017% ± 0.007% and 0.13 ± 0.05% per cycle. The overall AA rate per WP was 0.11% (940/849,650), 0.86% per cycle, including 320 critical assigns: sperm preparation: 83, oocyte retrieval: 34, IVF/ICSI: 173, (embryo)biopsy: 3, vitrification/warming: 6, embryo transfer: 0, medium changeover: 21. Critical AA rate per year was on average 0.041%/WP ± 0.01% and 0.30 ± 0.07% per cycle. All MM and AA rates remained stable during this 10-year period, except for sperm preparation, where the removal of a single witness point led to a huge increase in AA. RIW should still be used in combination with the manual labelling of bottom and lid of dishes and tubes to guarantee correct assignment in case of RFID malfunction or AA.

Limitations, reasons for caution

The procedures and method of integration of RIW may vary from one laboratory to another and result in differences in the potential risks. RIW cannot (yet) identify individual embryos, making double manual witnessing indispensable at certain critical steps, where potential errors are not recorded.

Wider implications of the findings

Using an electronic witnessing is considered to be the ultimate tool to safeguard correct identification of gametes and embryos. But this is only possible when used correctly and requires proper training and attention of the staff. It may also induce new risks, i.e. blind witnessing of samples by the operator.

Trial registration number

not applicable