Predicting Stillbirth Risk: The Role of Ultrasound and Sonus Array Technology

Twenty weeks into a pregnancy, optimism has grown with the development of a healthy fetus. Unfortunately, there is still the risk of one of healthcare’s most emotionally rending experiences: stillbirth, defined as the loss of a fetus after the 20th week of pregnancy. 

Experiencing a stillbirth is both emotionally and physically challenging, yet the risk of stillbirth is often unknown before it occurs. This unmet medical need demands innovative solutions.

Understanding the Role of the Placenta

Recent research, including a prospective clinical study at the PRIME Centre at BC Women’s Hospital, sheds light on the importance of the placenta in fetal development. It plays a critical role by supplying oxygen and nutrients to the fetus while removing waste, as well as providing immune protection and hormones that support fetal development. Given these key responsibilities, placental dysfunction can lead to severe complications, including pre-eclampsia, fetal growth restriction, and tragically, stillbirth.

Historically, the placenta has received less attention in obstetric research compared to maternal and fetal health. But initiatives like The Human Placenta Project and Wellcome Leap’s In Utero program, are rekindling research interest in this vital organ, emphasizing that early detection of placental insufficiencies can provide an opportunity for intervention and prevent adverse pregnancy outcomes. 

The Power of Ultrasound in Maternal-Fetal Medicine

Ultrasound serves as the cornerstone of prenatal imaging due to its safety, real-time capabilities, and the wealth of information it provides. Although doctors often use ultrasound to assess the progress of the pregnancy, its ability to evaluate placental health remains limited. Currently, standard obstetric ultrasound primarily focuses on placental location and identifying disorders like placenta previa or abruption.

While techniques such as Doppler ultrasound can offer glimpses into blood flow within the umbilical cord and uterine arteries, they do not provide a comprehensive assessment of placental function. This is where quantitative ultrasound (QUS) technology can revolutionize the field.

Advancing Ultrasound Technology with QUS

QUS is an innovative approach that involves analyzing the raw echo signals captured by ultrasound transducers rather than relying solely on processed images. By examining these signals, researchers can extract valuable insights into the tissue microstructure of organs. Traditional ultrasound only presents a greyscale image, while QUS reveals critical data about the intricate cellular environment within the organ.

Our collaborators at the University of British Columbia, conducted studies on ex vivo placental tissue which demonstrated a correlation between QUS measurements and pregnancy disorders, setting the stage for further research on placental evaluation in vivo. Through this, they have demonstrated that collecting quantitative ultrasound data to identify healthy versus non-healthy tissue, can lead to timely and life-saving interventions.

The Potential Role of Sonus Array Transducers

One of the most recent advancements that have the potential to enhance QUS measurements is Sonus’ development of polymer capacitive, micro-machined ultrasound transducers (polyCMUTs) which is being commercialized under the term Sonus Array Transducers (SAT). SATs promise significant benefits for QUS applications, not only in placental assessment but across various organ evaluations. The expanded bandwidth of polyCMUTs allow medical professionals to capture a wider range of ultrasound frequencies, much like hearing both the string and brass instruments of a symphony orchestra.

With these superior capabilities made possible by polyCMUTs, QUS analyses can yield more detailed and accurate results, enhancing the detection of potential disorders. This exciting technology, still under research, has the potential to unlock new horizons in prenatal imaging and placental health.

Collaborating Towards the Future

While the prospect of these technologies is promising, substantial work remains. Rigorous clinical studies are necessary to validate these findings across diverse patient populations. Furthermore, the successful integration of new technologies into clinical practices involves navigating regulatory approvals and gaining the trust of clinicians.

By offering reliable and user-friendly polyCMUT solutions, Sonus Microsystems is dedicated to facilitating advancements in joint studies and ultimately improving patient outcomes. Through collaborations like this, we at Sonus Microsystems are fully committed to working with these medical pioneers to further develop the Sonus Array technology and introducing them into emerging clinical applications.  

The journey toward preventing stillbirth is challenging, but with determination and innovation, we are making strides toward a healthier future.

References

1. Skidmore Goodman Perinatal Research IMaging and Evaluation (PRIME) Centre.. https://primeresearchcentre.med.ubc.ca/

2. Human Placenta Project. http://www.nichd.nih.gov/research/supported/human-placenta-project/default

3. Wellcome Leap In Utero program. https://wellcomeleap.org/inutero/

4. Farah Deeba, Ricky Hu, Victoria Lessoway, Jefferson Terry, Denise Pugash, Chantal Mayer, Jennifer Hutcheon, Robert Rohling. Development and validation of the placenta-QUS model for the detection of placenta-mediated diseases using quantitative ultrasound measurements: An Ex Vivo proof-of-concept study, Placenta, Volume 158, 2024, Pages 293-300, ISSN 0143-4004, https://doi.org/10.1016/j.placenta.2024.11.004.