Rachel Cutting, director of compliance at HFEA, said: “We are satisfied that Jessop’s undertook a thorough investigation when they first became aware of the issue and contacted and supported any patient affected.”

HFEA assured that any affected patients will have been notified.

Dr Jennifer Hill, Medical Director, Sheffield Teaching Hospitals NHS Foundation Trust said: “We began a thorough patient review as soon as the product recall notice was issued.

“We have robust tracing processes in our laboratories and so we were able to identify that there were 29 people who had eggs or embryos frozen in the period when we used the particular product batch.

A Guy’s and St Thomas’ NHS Foundation Trust spokesperson said the manufacturing issue may adversely impact the chance of a frozen egg or embryo surviving during thawing.

“We were made aware of a manufacturing issue with some bottles of a solution that may have been used to freeze eggs and embryos in our Assisted Conception Unit in September and October 2022,” they said.

They added that Guy’s Hospital has now contacted all those affected and apologised for the delay and any distress the error may have caused.

The Human Fertilisation & Embryology Authority (HFEA) said a safety notice about the faulty freezing system had been issued to all registered clinics in February 2023 – however the Guy’s Hospital clinic still used the faulty solution several months later.

The HFEA has launched an officiail investigation into the matter.