O-268 Cumulative toxicity of plastic disposable devices used during IVF procedures
Authors: Delaroche L , Besnard L , Genauzeau E , Meicler P , Lamazou F , Oger P 
Published: June 2022

Abstract

Study question
Is there a cumulative toxicity from the different plastic consumables used during IVF procedures?

Summary answer
A toxicity may be detected when IVF plastic consumables are cumulatively used, while no toxicity is detected when the same consumables are tested individually.

What is known already
Many components used in IVF laboratories, such as culture media and plastic consumables may impair human embryonic development. Consequently, it is necessary to screen all reagents and materials which will be in contact with gametes and embryos. Toxicity tests such as the Mouse Embryo Assay (MEA) and the Human Sperm Survival Assay (HSSA) are used by manufacturers as quality control tools to demonstrate the safety of their products. This evaluation is individually performed for each consumable, while in IVF several plastic devices are used, potentially creating a cumulative exposure to chemical contaminants which could not be detected for single consumables.

Study design, size, duration
The objective of this observational, prospective study was to evaluate the cumulative toxicity from the plastic consumables used during an IVF procedure. First, each consumable was tested individually using HSSA. Then, different associations of 3, 4 and 5 consumables, previously validated as non-embryotoxic, were tested. A total of 36 references of IVF plastic consumables were individually tested and 7 associations were tested.

Participants/materials, setting, methods
After obtaining the patients’consent, the leftovers of semen qualified with normal parameters according to the WHO 2010 criteria was used to perform the HSSAs according to the methodology described by Crichtlow et al. 1989. The items or associations were tested 3 times with 3 different semen to ensure the repeatability of the results. The toxicity threshold was defined by a Sperm Motility Index (SMI) less than 0.85 observed on at least 2 of 3 tests.

Main results and the role of chance
A total of 32 IVF plastic consumables from different manufacturers (Vitrolife, CCD, ThermoFisher Scientific, SparMED, Cryo Bio System, Apex Medical, VWR, Starstedt, Corning Science Mexico, Ellios Bio Tek, Sempermed, Cardinal Health, Codan Medical and Henke-Sass Wolf) were individually tested and revealed no toxicity: 200- and 1000-µl cones, condoms, 3-ml Pasteur pipets, 2- and 5-ml serological pipets, 35- and 100-mm dishes, 4 well dishes, examination nitrile powder-free gloves and latex powder-free nitrile coating microsurgical gloves, 1-ml syringes, soft embryo transfer catheters, oocyte pick-up needles, 5-, 14- and 15- ml tubes, cryotubes, sperm collection receptacles, sperm freezing straws, embryo vitrification straws). Four IVF consumables tested individually revealed toxicity: latex powder-free nitrile coating microsurgical gloves, 1-ml ethylene oxide sterilized syringes, 80-ml sperm collection cups, and 25-ml flasks. Three associations of 4 and 5 IVF disposables mimicking the chain of sperm preparation were found no toxic. However, 4 associations of 4 and 5 IVF disposables mimicking the chain of oocyte pick-up were found toxic. Further detailed results of this study will be presented at the conference.

Limitations, reasons for caution
The methodology of HSSA (extraction and incubation times, type of medium, temperature, chosen toxicity thresholds…) can affect the results. Thus, the HSSA may lack sensitivity for detecting toxicity.

Wider implications of the findings
Further studies are needed to quantify the cumulative levels of toxins (e.g. bisphenols) released from associated plastic devices during an IVF procedure. Also, professionals should rationalize and minimize the number of plastic consumables used during an IVF procedure to improve the environment in which the embryos develop.

Trial registration number
Not applicable