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Device reveals age of premature babies

Technology created in Minas Gerais supports healthcare for infants born prematurely

Without an obstetric ultrasound in early pregnancy, the gestational age of half of newborns in Brazil is inaccurate

Léo Ramos Chaves / Revista Pesquisa FAPESP

At this very moment, a small baby weighing less than expected is probably being born somewhere in Brazil. Maybe they are one of the 40 premature babies born every hour in the country. Or maybe not, since it is often difficult to know if babies born at a low weight had reached term or were premature (born before 37 weeks of gestation). About half of newborns in Brazil are born with an inaccurate gestational age because no obstetric ultrasound was performed in the first three months of the mother’s pregnancy (see Pesquisa FAPESP issue no. 271). This situation can put the baby at risk because if they are premature, they need immediate special care to prevent problems that could permanently damage their health or even be fatal.

“Gestational age at birth is the most important information to determining the prognosis of a newborn, its chance of survival, and the care it will need in the first hours of life,” stresses gynecologist Zilma Reis, from the School of Medicine at the Federal University of Minas Gerais (UFMG). “In the absence of reliable information, prematurity can be missed, leading to reduced probability of survival,” adds the doctor, who also heads the Health Informatics Center at UFMG.

It was with the objective of offering a quick and safe response to this situation, especially in locations lacking specialized professionals, that Reis joined forces with physicist Rodney Guimarães and a group of UFMG researchers from the fields of neonatology and obstetrics, nursing, physiotherapy, physics, computer science, and data science. The result of seven years of hard work was transformed into a product that went on sale in October last year. Named the Preemie-Test, the 15-centimeter-long device, which looks a bit like a digital thermometer, estimates a newborn baby’s age at birth by analyzing the maturity of its skin. It does so by shining an LED (light-emitting diode) light onto the sole of the baby’s foot and measuring how much light is reflected back (see infographic).

“The more premature a baby is, the more transparent its skin is. As a result, more of the radiation is absorbed and less is reflected back at the device. With a longer gestation period, the skin becomes thicker, reflecting more light, which is captured by the sensor,” explains Reis. “We tested lights of various wavelengths and opted for infrared, which is better at penetrating the skin,” adds Guimarães, noting that the light and its absorption by the skin causes no harm to a newborn’s health.

Alexandre Affonso / Revista Pesquisa FAPESP

Information about the maturity of the skin, together with the baby’s weight, is analyzed by software that uses artificial intelligence to estimate the gestational age. The device also considers whether the pregnant woman used corticosteroids during prenatal care, since this medication accelerates the maturation of the fetus—information on the use of corticosteroids is collected from the mother and inserted into the Preemie-Test software. “There is no similar technology on the market to identify pregnancy chronology,” says the researcher.

The Preemie-Test is manufactured by BirthTech, a startup founded by Guimarães that has a licensing agreement with UFMG. Headquartered in Belo Horizonte, it also has a branch in the small town of Figueiró dos Vinhos, central Portugal, where the physicist lives and produces the equipment. “I chose Portugal because there is less bureaucracy in the manufacturing and export process. We receive financial support from the European Social Fund to pay our staff. These funds cover 40% of the salary of our four employees, including an engineer, all of whom are Portuguese,” reports Guimarães.

In its first month of sales, the Preemie-Test was exported from Europe to India, Costa Rica, Guatemala, Mexico, Colombia, and Trinidad and Tobago. Twenty units were sold in total. The startup still does not have any clients in Portugal or Brazil. “In November, we obtained authorization from the Brazilian Health Regulatory Agency (ANVISA) to sell the device in the country,” says Guimarães.

The pioneering device was conceived from the combined knowledge of a gynecologist and obstetrician who left a civil engineering course halfway through to begin studying medicine and a doctor in astrophysics who completed a postdoctorate in biomedicine. “We met when Zilma was on the examination board for one of my master’s students who had created an oximeter as part of their research,” recalls Guimarães, who was a professor at SENAI Cimatec in Bahia at the time. The principle of the oximeter, a device used to estimate the blood oxygen levels by shining light through the skin, was the inspiration for the Preemie-Test.

The idea of using the technique to identify preterm babies only came to reality thanks to funding from the Bill & Melinda Gates Foundation in 2015, which was matched by the Minas Gerais State Research Foundation (FAPEMIG). “Bill and Melinda Gates’s investment was essential to making the project viable. They placed their belief in my two-page summary,” says Guimarães. The funds were used to make a proof of concept, demonstrating that the amount of light reflected correlated with skin maturity. The results were published in the journal PLOS ONE in 2017. About a year and a half later, the technology and the device were patented under the name of UFMG and FAPEMIG.

Daniel Mansur / Revista Pesquisa FAPESPThermometer-like device estimates age at birth by analyzing the maturity of the newborn baby’s skinDaniel Mansur / Revista Pesquisa FAPESP

In 2018, the project was selected by the Grand Challenges Canada program, funded by the Canadian government. With this investment, the device was used to assess 305 babies born weighing less than 2.5 kg in Brazil and Mozambique between June 2020 and April 2021. “Obstacles are opportunities,” says the UFMG researcher. “Given the scarcity of research funding in Brazil, we started focusing on international calls for proposals. We put our efforts into partnerships outside Brazil to improve results and raise more money.” The Oswaldo Cruz Foundation (FIOCRUZ), which has an office in Maputo, the capital of Mozambique, also participated in the test, the results of which are currently being prepared for publication.

According to Reis, the device was more than 90% accurate in the tests. In one study involving 781 babies born at five Brazilian hospitals between 2019 and 2021, the device distinguished between full-term and preterm babies with a 91% accuracy rate. The results were published in the Journal of Medical Internet Research in September 2022.

In 2020, a new patent was filed by UFMG, FAPEMIG, and BirthTech, including a number of technological improvements. The changes reduced the device’s original size and added a new function associated with newborn lung health. “The initial version was only able to date the pregnancy. The update provides a prognosis of pulmonary complications related to gestational maturity,” says Reis.

She explains that there is a direct relationship between lung maturity and the skin’s ability to retain heat, both of which depend on the amount of time the fetus spent in the womb. Based on the clinical trial data that demonstrated the relationship between the lungs and the skin (the last organs of the human body to mature) the algorithm estimates the risk that a baby will suffer breathing difficulties and may require intensive care.

The creators of the Preemie-Test emphasize that the device is not intended to replace conventional forms of gestational dating, but to support health professionals, especially where technological and human resources are lacking. The group also created an app—Preemie Care—which can be downloaded for free and offers guidelines on initial care for premature infants.

Alexandre Affonso / Revista Pesquisa FAPESP

The startup earned praise from Ruth Guinsburg, a pediatrician and neonatologist from the Federal University of São Paulo (UNIFESP) and scientific coordinator of the Brazilian Neonatal Research Network. “It can support the decision-making of healthcare professionals who have to act quickly,” she says. She highlights that the first response of health professionals in the delivery room is crucial to preventing mortality and impacts on neuropsychomotor development. However, data on the newborn baby are often limited and imprecise.

“We calculate the gestational age from the date of the mother’s last menstrual period—assuming their cycle was regular and she is sure of the date—and on ultrasound exams carried out before the 12th week of pregnancy,” explains Guinsburg. When performed within the first 12 weeks, an ultrasound is the best method for accurately calculating gestational age, considered the gold standard with a margin of error of up to five days, explains the pediatrician.

The results achieved by the Preemie-Test during development by the UFMG scientists were almost as good as an ultrasound performed in the first trimester of pregnancy. “On average, the gestational ages obtained by the device were 1.3 days less than the ultrasounds calculated,” says Reis.

In the absence of an ultrasound, the alternative is to submit the newborn baby to physical examinations, which are more influenced by the professional’s experience and have a greater margin of error. A review published in the journal Pediatrics in 2017 on the Ballard test, one of the most frequently used methods for assessing the physical and neuromuscular maturity of newborns, indicated that the test estimates gestational age with a margin of error of 3.8 weeks.

Walusa Ferri, a neonatologist from USP’s Ribeirão Preto School of Medicine (FMRP) and head of the Neonatology Department at the university’s teaching hospital, believes analyzing the maturity of the baby’s skin in itself is valuable, regardless of the relationship with lung maturity. She explains that monitoring the skin of premature babies is essential to prevent serious complications.

“Premature babies lose water through their skin—it evaporates through the epidermis, which is extremely thin, meaning they need to replace these lost liquids intravenously. If this intervention doesn’t occur, they can dehydrate to the point of suffering intracranial bleeding,” warns the specialist. Information about skin maturity, she explains, can help health professionals estimate the volume of intravenous replacement needed. “In locations with few resources, this device could be of great value,” emphasizes Ferri.

Scientific articles
REIS, Z. S. N et al. Newborn skin reflection: Proof of concept for a new approach for predicting gestational age at birth. A cross-sectional study. PLOS ONE. sept. 20, 2017.
REIS, Z. S. N et al. Newborn skin maturity medical device validation for gestational age prediction: Clinical trial. Journal of Medical Internet Research. sept. 7, 2022.
REIS, Z. S. N et al. Premature or small for gestational age discrimination international multicenter trial protocol for classification of the low-birth-weight newborn through the optical properties of the skin. JMIR Research Protocols. july 14, 2020.
LEE, A. C. et al. Diagnostic accuracy of neonatal assessment for gestational age determination: A systematic review. Pediatrics. nov. 17, 2017.