Dishes with embryos of 11 patients were observed to be contaminated with cellular debris that may have contained sperm

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Record number: 
Adverse Occurrence type: 
MPHO Type: 
Estimated frequency: 
Very rare
Time to detection: 
1 day
Alerting signals, symptoms, evidence of occurrence: 
Dishes for embryo culture for the next day were prepared (i.e. labelled, filled with appropriate volumes of specific media and placed in an incubator to equilibrate) according to the centre’s standard operating procedure (SOP) for this activity. Post ICSI treated eggs were moved into embryo culture drops. This procedure was performed with the aid of a low power microscope. Fertilised eggs following conventional IVF were also moved into embryo culture drops. The next day, using a microscope to carry out fertilisation checks on ICSI processed eggs an embryologist noticed contamination, of low level, present in all dishes containing ICSI treated eggs/embryos and recognised the possibility that the IVF produced embryos may also be contaminated.
Demonstration of imputability or root cause: 
The most likely explanation is that the barrel of a pipettor seems to have been contaminated. The barrel of the pipette is not sterile but can come into contact with the inside of a bottle of medium and in this way contamination could theoretically occur.
Groups audience: 
Suggest references: 
HFEA. Adverse incidents in fertility clinics: lessons to learn, 2010-2014
Expert comments for publication: 
Pipetting techniques should be observed and auditied on a regular basis to ensure good laboratroy pracitice is being adhered to. All laboratory staff hould follow good laboratory practice in realtion to pipetting: for example filtered pippette tips should be used.