The Thirlwall Inquiry, established to investigate serious concerns regarding maternity care at the Countess of Chester Hospital, has faced criticism for sidelining key questions about the guilt of nurse Lucy Letby. Since its inception in 2024, the inquiry has focused on institutional failings rather than directly addressing Letby’s convictions in connection with infant deaths and collapses, prompting controversy over its scope and timing.

Led by Lady Justice Thirlwall, the inquiry has operated amid a backdrop of growing public and professional debate. At the outset, Lady Justice Thirlwall expressed frustration with what she described as “uninformed” commentary about Letby’s guilt, highlighting the distress caused to families of victims. However, in her closing remarks, she acknowledged that the inquiry’s terms of reference explicitly exclude revisiting Letby’s conviction, stating, “it’s not for me to second guess or cut across the world of the Criminal Cases Review Commission (CCRC).” This delineation has raised questions about the inquiry’s purpose, especially given that the CCRC is expected to soon decide whether to refer Letby’s case back to the Court of Appeal.

The timing of the inquiry’s report release also drew scrutiny, as it precedes a potential CCRC recommendation that could alter the case’s trajectory. If the court were to grant an appeal, it could negate the inquiry’s foundational premise. Critics argue that the inquiry’s failure to engage with new scientific developments, notably recent research indicating that abnormal insulin spikes in newborns can be typical, undermines its comprehensiveness. Furthermore, a panel of international experts—including Professor Neena Modi, former president of the Royal College of Paediatrics and Child Health—has reassessed the evidence, attributing infant deaths partly to prematurity and substandard care rather than malicious acts.

Supporters of Letby, comprising respected medical professionals and scientists, have publicly challenged the prosecution’s case, confronting potential professional repercussions. Several families have also come forward recounting instances of inadequate care at the hospital unrelated to Letby’s involvement, suggesting systemic issues beyond individual culpability.

Despite the controversy, the inquiry put forward a series of recommendations aimed at enhancing patient safety within neonatal services. These include improved safeguarding procedures, encouraging staff to raise concerns without fear of reprisal, and better oversight of hospital management to prevent personnel from moving unchecked between trusts after performance issues. Additionally, Lady Justice Thirlwall proposed establishing an independent expert panel to investigate harm allegations impartially, rather than relying solely on internal hospital reviews.

Letby’s defence team welcomed certain recommendations—such as installing baby monitors on cots and incubators and placing CCTV in insulin storage areas—arguing these measures could have influenced the original trial’s outcome. Mark McDonald, Letby’s barrister, suggested that such safeguards might prevent future miscarriages of justice.

While the inquiry stops short of resolving doubts over Letby’s guilt, it aims to improve maternity care standards and prevent similar tragedies. Whether its findings will withstand the evolving legal process remains to be seen, but the emphasis on systemic reform reflects a broader effort to enhance patient safety in NHS neonatal units.