The number of frozen eggs and embryos a Cleveland fertility center says were lost in a tank failure has doubled since the incident was first reported earlier this month, NBC News reported.
The hospital is now blaming human error for the loss of 4,000 eggs and embryos, and it told nearly 1,000 patients that it is unlikely any egg or embryo is viable.
NBC News has also uncovered a history of malfunctions from the manufacturer, Custom Biogenic Systems, which declined to comment.
British regulators issued a warning about the company's freezers in 2003 after Custom Biogenic Systems reported knowing about 21 incidents. The alert was later withdrawn as upgrades were made, but at least one problem was reported subsequent to the alert, in Florida.