More than two dozen women in the Netherlands may have been fertilised with sperm from the wrong man, following a suspected donor mix-up at a Dutch IVF treatment clinic. 

The Utrecht University Medical Centre said a "procedural error" was to blame, explaining that sperm cells from one treatment couple "may have ended up with the egg cells of 26 other couples." 

Initial indications are that the error was caused by a lab technician who mistakenly used the same rubber top on a pipette used to inject various batches of sperm. The mistake began in April 2015 and only ended in November 2016, when the error was discovered. 

Of the 26 couples involved, nine have had children and four women are currently pregnant. All couples have been notified of the mix-up and are due to meet with doctors from the centre in the coming days, the medical centre said.