Partners sought for delivery room probe that can pinpoint foetal hypoxia faster
This article was originally published in Clinica
An investigational point-of-care probe for use during childbirth could dramatically speed up diagnosis for foetal hypoxia - a dangerous condition in which the brain of the unborn child is starved of oxygen.
The device, devised by Nick Dale of the University of Warwick in the UK, might also reduce costs for healthcare systems by decreasing the number of C-sections performed.
Foetal hypoxia carries dangers for both the child and mother, as doctors often resort quickly to a C-section if they believe there is a significant threat of the condition. It is currently diagnosed using foetal scalp blood samples that are taken to a laboratory where a blood gas analyser is used to measure pH. This process, however, is time-consuming and doctors sometimes decide to proceed with the C-section section rather than risk waiting for a full analysis. In addition, current testing often gives rise to false positive results; the test must identify a shift of as little of 0.05 pH.
"If our probe-based test were to reduce the number of false-positives, it would be a considerable saving to the UK NHS as C-section rates are approaching 30% in some maternity units," Professor Dale told Clinica. "Normal delivery costs around £1,700 ($3,000), an emergency C-section around £3,200, with three days in patient care - another £1,500."
Conversely, around 5% of babies are born having suffered intrauterine hypoxia. "Thus a test that more accurately diagnoses this condition would lower this percentage and the consequent additional costs to the NHS of treating the effects of this condition."
The probe consists of a biosensor that will be incorporated into a fluidic device and connected to a handheld instrument suitable for use in the delivery room. It will measure levels of hypoxanthine, a chemical in blood that has been shown to correlate with measures of hypoxia and of blood pH; an unborn child with over five micromoles of hypoxanthine per litre of blood is at severe risk of foetal hypoxia. The test is expected to provide a result in a just couple of minutes.
"To our knowledge, no one is actively proposing to use hypoxanthine as a marker [for foetal hypoxia] or attempting to produce a diagnostic device based upon this marker," noted Professor Dale.
Further development of the probe is now taking place in collaboration with University of Warwick spin-out firm Sarissa Biomedical; Professor Dale is a founding director of the Coventry-based company. Sarissa is aiming to establish a partnership with a medical instrument manufacturer and venture capitalists to produce a full-blown medical product, which will then be tested in clinical trials. Following the completion of a successful trial, a licensing deal will be sought with a major global diagnostics company.
"The probe is currently at the stage of a laboratory device that can be manufactured, but we still need to make the transition to a commercial device," explained Professor Dale. It already comprises the correct analytical characteristics in terms of sensitivity, stability, dynamic range, rejection of interferences and ability to operate with plasma. "We still need to incorporate it into a fluidic package for reliable sample delivery and to verify that it will work accurately and reproducibly with blood and in a clinical setting."
A UK clinical trial of the probe is scheduled to take place in 18-24 months; just how soon will depends upon how quickly financial support is generated. During the trial, a portion of blood ordered for conventional pH testing will be retained in the delivery room, where it will be introduced into the device.
Sarissa already sells, for analytical research-use only, microelectrode biosensors for ATP, adenosine and inosine. "Our foetal hypoxia biosensor will be our first step into producing diagnostic biosensors," Professor Dale said. The company is also developing a sensor for stroke.