Open Letter Response to the INFANT Study

The INFANT Study found no difference between the two arms of the trial tested, INFANT+Guardian versus Guardian alone, because the study design was flawed and all women recruited benefited from good quality care with very low risk of poor perinatal outcome.

The nature of the flaws were set out in the Lancet publication, ( The trial design was known to be flawed by all involved at the time of making the application to the NIHR in 2006. Members of the INFANT Clinical Investigators Group, INFANT Clinical Collaborators and NIHR referees made the issues clear at the time. The contemporaneous correspondence related to this matter is published Despite these issues, this flawed trial design went forward un-amended.

The risk of a poorest perinatal outcome observed during the INFANT Study was very low indeed, much lower than is found in UK Obstetric Units without K2 technology. This comparison is summarised in the following table:

INFANT-Guardian® Hospitals’ Incidence
Other UK Obstetric Hospitals’ Incidence
Intrapartum Stillbirths 0.6 per 10,000 births 2.6 per 10,000 births
Moderate or Severe Brain Damage 0.78 per 1,000 births 2.0 per 1,000 births
Poorest Perinatal Outcomes
(Stillbirths + Neonatal Deaths + Brain Damage)
1.1 per 1,000 births 2.57 per 1,000 births


Some are taking the null finding of the INFANT Study to question the physiological basis of fetal heart rate to assess fetal wellbeing during labour. Such a conclusion would obviously apply equally to CTGs and intermittent auscultation as both observe the same physiology. Such an interpretation would set care during labour back decades, if not a century in our view.

But such a conclusion is to ignore the foreseen flaws of the study design and the very low incidences of poorest perinatal outcomes observed in 47,000 births. There was no difference between the arms of the INFANT Study, not because both arms offered poor care or typical care, but because both arms offered low risks of human errors leading to poorest perinatal outcomes.

K2 is promoting a positive message that with technology to facilitate communication and senior clinical staff oversight (Guardian) and technology to monitor fetal heart rate continuously, to alert remotely and help improve clinical skills at the point of care (INFANT), that human errors that so blight life chances of a significant few can be reduced.

There was no case of hypoxic outcome for which INFANT failed to raise appropriate concern in a timely manner. INFANT can be seen as a logical progression of the rationale behind the RCOG/NICE guidelines for CTG interpretation, bringing a standard model of interpretation right to the point of care. The difference being that INFANT works in real time, is consistently applied and has undergone unprecedented evaluation. All parties agree that INFANT offers no negative effects.

A full elaboration of K2’s rationale and intended approach can be found in our enclosed publication, ‘Improving Birth Outcomes, A series in four volumes’. Further information is available to download or view from

K2 would very much like to work with the RCOG, BMFMS, RCM, Government and interested parties to bring about improvements in birth outcomes. Goals that we have been dedicated to achieving for three decades now. We would be happy to meet at any time to explore how best to achieve this common aim.

Yours sincerely,

Dr Robert Keith MEng CEng FIET Ph
Director General