Expanding Newborn Screening Through Global Collaboration: A Conversation With Dr. Bradford Therrell

CLSI NBS01, as it stands today, remains the starting point for new programs in the United States and in other countries around the world. It offers a clear, consensus-based framework for collecting dried blood specimens, something that didn’t exist in the early days of newborn screening. Before its development, programs were left to figure out their own methods, often producing inconsistent results or errors. Understanding where newborn screening started and where it landed shows just how transformative CLSI NBS01 has been for the field.

“If you don’t have a good specimen, you don’t have anything,” Dr. Therrell said. “That’s why this standard became so important. It gave everyone a consistent way to collect quality specimens that laboratories could actually use.”

Before CLSI NBS01 - The Wild West of Newborn Screening

In the 1970’s and 1980’s, newborn screening programs didn’t have the sophistication they have today. In the years before the widespread use of CLSI NBS01, there were no uniform collection methods. Every laboratory and every nurse had their own way of collecting blood from babies’ heels. 

Paper quality was inconsistent with labs using random commercial filter papers not designed for clinical use. Absorbency varied wildly. Blood dried unevenly, flaked off, or didn’t have enough volume for testing. This led to false negatives, false positives, or unreadable specimens. Errors led to high repeat rates, delaying diagnosis, and in some cases missed detection of serious disorders. 

“One of the biggest problems is how do you take a good specimen from a baby so that you get enough blood to do the test in the laboratory, “Dr. Therrell said. “People, at that time, were sort of flailing around. Some would stick it two or three times. Some people would make an X when they stuck it. Some would have a deeper lancet, others a shorter lancet. There were all sorts of things going on.”

CLSI NBS01, and Dr. Therrell’s work to advance guidance, helped bridge the gap with training and documentation. Before, collection procedures weren’t written down or taught consistently. Programs were scrambling to build systems from scratch. But CLSI's NBS01 gave newborn screening programs their first consistent, consensus-based protocol for specimen collection and paper standards. This meant standardized heel-stick methods, quality specifications for collection paper, lower rejection rates, and faster, more reliable diagnoses.

Expanding Access to Newborn Screening Worldwide

Dr. Therrell’s work alongside his peers has made it possible for all 50 states, as well as the District of Columbia and Puerto Rico, to establish universal newborn screening programs. Now, his focus has shifted to a new challenge: helping developing nations without access to safe and reliable newborn screening build systems from the ground up. 

The goal is no longer just improving quality where programs already exist but expanding access to places that have none.

As more countries begin to explore newborn screening and use the guidance found in CLSI NBS01, international collaboration has also grown. Global health organizations such as the World Health Organization (WHO) have begun developing guidance and resources for countries interested in launching their own programs. This has created new momentum in nations where screening has been historically limited, or non-existent.

Dr. Therrell has been actively involved in these international efforts, participating in WHO working groups and collaborating with emerging programs, most notably across Asia. In the past year, he’s worked with teams in Nepal and Bangladesh as they begin building their national screening infrastructures.

“I’ve worked with programs for years that wanted to know what WHO thought,” he said. “Now that WHO is taking a position, countries like India are listening and beginning to develop more and more programs,” Dr. Therrell said.

With the inclusion of more experts, organizations, and resources, more developing countries are recognizing newborn screening has a vital public health priority, expanding its reach and making it possible to reach babies who have never had access to it before. 

CLSI's Role with Country-Based Pricing - Removing Barriers

Dr. Therrell stresses that one of the biggest hurdles for countries and access to standards is still a matter of cost, even as interest in newborn screening grows. CLSI has introduced its Country-Based Pricing model, which offers up to a 90% discount on documents for eligible countries.

This pricing model has made vital guidance more accessible to laboratories who are just beginning to push ahead and advance their laboratory medicine practices, changing patient care for the better and improving quality of life in the country.

“New programs are the ones using the foundational standards,” Dr. Therrell said. “They need them the most, and the discount has made that possible.”

CLSI’s Country-Based Pricing reduces financial burdens, helping new programs gain the tools they need to launch screening, improve quality, and begin saving lives.

What's Next for Newborn Screening?

From a single test detecting PKU to a dried drop of blood that can reveal dozens of conditions and health concerns for newborns, screening practices have not only evolved dramatically. These advancements have not only improved care but have also inspired other countries and laboratorians to expand their programs, detecting more diseases and transforming how newborn screening data is managed.

Expansion now often means adding dozens or even hundreds of genetic conditions through molecular testing techniques that analyze and identify specific molecules such as DNA, RNA, and proteins in biological samples. Before newborn screening had thorough guidance, PKU was the only condition actively tested for. Today, that model includes 30+ conditions, and some experts hope that developments in molecular testing could open the door to 300 or more.

“Back then, expansion meant moving from one condition to two,” Dr. Therrell said. “Now we’re talking about going from 50 to 100, or even 300.”

CLSI NBS01 includes guidance for ensuring specimens are suitable for molecular testing, helping push laboratory medicine forward, and laying the groundwork for programs to branch out even further in the future.
With the emergence of AI tools, managing and understanding large datasets has become easier, and reporting to families and providers has grown more seamless. AI is also beginning to assist with the design and growth of newborn screening programs, and could eventually help speed up result turnaround times and improve public understanding and policy support.

Though the early days of AI weren’t reliable, Dr. Therrell noted it’s rapidly improving and turning into a revolutionary tool:

“AI will not only help us with data management, but it’ll help us get babies in quicker and better, and help parents and even politicians understand what’s going on,” Dr. Therrell said.

The Lasting Impact

Over the decades, many experts, laboratorians, and public health leaders have contributed to the development and ongoing improvement of CLSI NBS01. Their collaboration and dedication has helped turn newborn screening into a reliable, standardized practice that continues to serve as a foundation for programs around the world.

As newborn screening expands to includes even more advanced procedure like AI-driven data systems, molecular testing, and broader international collaboration, standards like CLSI NBS01 will remain essential for guiding quality and consistency as new programs emerge and existing ones evolve.

Elevate Newborn Screening in Your Laboratory

Explore guidance in CLSI NBS documents that help your laboratory ensure quality, accuracy, and life-saving results for newborn patients.