Donna Ockenden, who is leading the investigation into baby deaths at Shrewsbury and Telford Hospital NHS Trust, has warned it is unlikely records more than two decades old will be accessible to the inquiry.
But she has urged families, who may not have done so yet, to come forward if they believe they have received poor care:
It comes after a leaked report into the inquiry last week revealed a catalogue of concerns and that dozens of babies and mothers are thought to have died or been left disabled due to poor care at the trust, which runs Royal Shrewsbury Hospital and Telford's Princess Royal Hospital.
Ms Ockenden is reviewing more than 600 cases linked to poor care at the trust going back 40 years.
She said: "My priority has always been the welfare of every family who may have concerns about the maternity care they received at the trust.
"Every family that has a story to tell deserves to be listened to with compassion and kindness and with their wishes respected every step of the way.
"This is not a process that can be rushed.
"Equally, it must not be a process that feels incomplete.
"By the time I complete my report at the end of 2020, I want to make sure we have done all we can to reach every family who has raised concerns.
"There will come a point next year when my independent review will have to focus on the cases we have in front of us, so that we can progress with writing our report.
"That’s not to say new families won’t be able to get in touch. But we want to have the time to listen to them and consider how their stories shape the final report."
She said families who come forward will be listened to with "kindness and compassion" and will not have to do or say anything they don’t want to.
However, she also pointed out that it may be more difficult to access very old health records.
She added: "Whilst we want to hear from any family with potentially significant or serious concerns regarding maternity care at SaTH it is important that families understand that the further back in time we go, the less likely we are to be able to access health records since health records in the NHS are routinely kept for 25 years.
"After that time it is unlikely we will be able to access records.
"Please be assured, however, that your story will be heard and we will continue to try and get you the answers you deserve."
The inquiry was launched in 2017 following the efforts of Rhiannon and Richard Stanton Davies, whose daughter Kate died shortly after birth in 2009, and Kayleigh and Colin Griffiths, whose daughter Pippa died shortly after birth in 2016.
At a board meeting on Thursday, SaTH's interim chief executive Paula Clark said there was an acknowledgement of failures in maternity services and that patients have been let down.
She said the trust had made changes and continues to do so, but added there was "further to go".
To get in touch with Ms Ockenden call 01243 786993.