Research carried out at the University of Sheffield into electrical impedance spectroscopy (EIS) has led to the creation of a device designed to improve the prediction of preterm birth at a fraction of the cost of current methods. The EIS device has been brought to the market by EveryBaby, a UK company backed by South Korean investors.
Technologies for assessing the likelihood of preterm birth, like transvaginal ultrasound, are expensive and not always available, especially to patients in resource-limited countries. EIS, however, can pick up on changes to the composition of cervical tissue as a pregnant person nears birth, which can provide a greater degree of accuracy inside a low-cost handheld device.
This format gives it significant potential in resource-limited countries, where full-scale hospital equipment may not be possible to run and a portable solution is needed.
How does EIS work in the EveryBaby device?
University of Sheffield professor of obstetrics and gynaecology Dilly O’Anumba says: “EIS assesses the response of cervical tissue to a small current, called resistance or impedance. The tissue response depends on how tightly packed the cells are together, the water content of the tissue and the nature of the cells within that tissue.
“Prior to birth these tissue features change dramatically in a process called remodelling. We now know that some of this remodelling occurs several weeks to months before labour starts. EIS detects these changes in women likely to deliver preterm earlier than in women whose pregnancies will go to full term.”
Pregnant people who are likely to deliver preterm tend to have lower resistance or impedance mid-pregnancy than those who are going to deliver at term. By working out which patients have lower cervical tissue impedance, clinicians can know which patients are at risk and recommend appropriate care.
O’Anumba says this could mean “treatments to defer birth (some of which are currently not started early enough and in the women who truly need it), referral to more appropriate facilities as well as reassurance of women that their chance of premature birth is low thereby avoiding unnecessary treatment and hospital stay”.
Low-cost, portable and handheld
O’Anumba’s team has spent over four years researching the potential of EIS to improve prediction of preterm birth. In a study of 449 pregnant women, they found that the device was able to predict spontaneous delivery before 37 weeks gestation with higher accuracy than transvaginal ultrasound or foetal fibronectin estimation.
The device can provide an assessment of preterm birth risk as early as the 18th week of pregnancy, a critical stage for clinicians to address any associated complications.
The World Health Organisation (WHO) estimates that 15 million babies are born premature every year, which can lead to long-term complications like learning disabilities and visual or hearing impairments. Complications arising from premature births are the leading cause of death in children under five.
According to the WHO Born Too Soon report, over 90% of extremely preterm babies born before the 28-week mark in low-income countries die within the first few days of life. However, less than 10% of extremely premature infants die in higher-income countries. By making a portable, handheld EIS device available to assess the risk of premature birth at a low cost, EveryBaby has the potential to help change these statistics.
O’Anumba says: “The previous generations of this device have been used to study over a thousand pregnant women and the results inform this new initiative to develop the next version for clinical use. The studies show it is safe and acceptable to pregnant women. The next version is currently being manufactured for global clinical studies and use.”