The normal length of a pregnancy is 40 weeks, while babies born before 37 weeks gestation are considered to be preterm. By detecting preterm contractions with greater accuracy and sensitivity than existing tools, the new system could allow doctors to take steps at an earlier stage to prevent premature births, its inventors said.
The health concerns and costs associated with premature births have received increasing attention in recent years, due in part to a rise in the number of multiple births, to the use of fertility treatments, which can cause multiple births, and to an increase in women who are having babies later in life. These trends are all associated with a higher risk of preterm labour.
The scope of the problem is significant: The National Center for Health Statistics has reported that about 500.000 premature live births occur annually in the United States alone. In a 2006 report, the Institute of Medicine described the high rate of premature births in the United States as "a public health concern that costs society at least $26 billion a year". Preterm births are widely linked to neonatal deaths or serious health problems such as breathing difficulties and brain development issues.
To help reduce these statistics, the Johns Hopkins biomedical engineering students wanted to improve the way doctors detect preterm labour. They designed and built a prototype that is now undergoing testing in animals. With further refinement, the students said, their system could eventually help physicians discover early signs of labour and allow the doctors to delay preterm deliveries, giving these babies more time to mature.
"The problem is, the technology now used by most doctors usually detects preterm labour when it's so far along that medications can only delay some of these births for a few days", stated Karin Hwang of Ontario, California, one of the student inventors. "But if labour can be detected earlier, medications can sometimes prolong the pregnancy by as much as six weeks."
Karin Hwang was one of four Johns Hopkins students who devised and built the system in a yearlong bioengineering innovations and design master's degree programme. The others were Deepika Sagaram of Philadelphia; Rose Huang of Brooklyn, New York; and Chris Courville of Lafayette, Louisiana. Along with their faculty sponsor, Abimbola Aina-Mumuney, an assistant professor of maternal foetal medicine in the Johns Hopkins School of Medicine, the students have formed CervoCheck, a limited liability corporation, to advance the project.
The students met Abimbola Aina-Mumuney last year, early in their degree programme, when they were asked to follow physicians on their hospital rounds and discover which new instruments and devices the doctors needed most to improve patient care. "I told them it's really important to know at the earliest possible point when a pregnant patient is contracting", stated Abimbola Aina-Mumuney. "It's something I've had a strong interest in."
The students initially proposed a new blood test to find proteins associated with early labour, but Abimbola Aina-Mumuney steered them toward building a better device to detect physical signals in the expectant mother's body. To find signs of preterm labour, physicians have long relied on a tocodynamometer, a belt that is attached to a woman's abdomen for external monitoring of uterine contractions. But Abimbola Aina-Mumuney said this device is not effective at picking up preterm labour very early in a pregnancy or in cases where the patient is obese. "I suggested that the students come up with an internal device", she stated. "I told them that if we could bypass the abdomen, that would be ideal."
After much research and brainstorming, the students built a prototype ring made of medical grade biocompatible silicone elastomer. The ring is designed to be compressed and inserted into the vaginal canal at a physician's office or hospital. Embedded within the ring are sensors designed to pick up electrical signals associated with uterine contractions.
"With these sensors, we're detecting signals directly from the places in the body where they originate, as opposed to trying to pick them up through the abdominal wall", stated Chris Courville, one of the inventors.
The prototype has not yet been used on human patients, but the students say their early animal test results are promising and that improvement of the system is continuing. Their faculty advisor, Abimbola Aina-Mumuney, said she is pleased by the great enthusiasm that the biomedical engineering students brought to the project. "They can truly see the impact this could make", she stated. "If we can detect preterm labour at an earlier point and can delay the delivery by six weeks or more, the risk of the baby being born with serious health problems will go down dramatically."
The costs of caring for premature babies are significant. A recent article in Managed Care said: "The average cost for infants hospitalized in neonatal intensive care units is around $3000 per day. While the average cost to an employer of a healthy baby born at full-term, or 40 weeks of gestation, is $2830, the average cost for a premature baby is $41.610. If the baby is born at 26 weeks, the cost can quickly rise to $250.000 or more."
The inventors of the CervoCheck device say their system may someday help to reduce such expenses. "We estimate that the cost savings could be more than $44.000 per patient for every preterm birth we could prevent", co-inventor Karin Hwang stated.
Working with the Johns Hopkins Technology Transfer office, the students and Abimbola Aina-Mumuney have obtained a provisional patent covering their invention and established CervoCheck LLC. The students also have received high marks and prize money in several competitions in which the viability of their device and its sales potential were judged. The team placed first in the University of California, San Francisco, Business Plan Competition; won second-place honours in business plan contests sponsored by the University of Texas at Arlington and Noetic Technologies, and placed third in the University of Louisville Cardinal Challenge and the Johns Hopkins University Business Plan Competition. The team's winnings from these contests totaled $22.000.
All four students recently received their master's degrees from Johns Hopkins. Deepika Sagaram will be entering medical school at Brown University, and Chris Courville has accepted a job at a health care software business. Team members Karin Hwang and Rose Huang have opted to work full-time on moving the CervoCheck device toward commercial use. "We're passionate about seeing this become a reality", Karin Hwang stated.