Every baby born in the United States is screened for sickle cell disease as part of routine newborn testing, a process that begins with a small blood sample taken from the baby’s heel in the first day or two of life. Results typically reach the baby’s pediatrician or primary care provider within one to three weeks. Because the screening is automatic and happens in the hospital before discharge, most parents never need to request it, but knowing how the process works, where results go, and what to do if you never hear back can save you from falling through the cracks.
How Newborn Screening Works
Shortly after birth, a nurse or technician pricks the baby’s heel and collects a few drops of blood on a special filter-paper card. That card is sent to a state public health laboratory, where it is tested for dozens of conditions at once, including sickle cell disease and sickle cell trait. The screening has been required in all 50 states since 2006, though a national recommendation to screen every newborn for sickle cell disease was first issued back in 1987.1PubMed. History and current status of newborn screening for hemoglobinopathies The nearly two-decade gap between recommendation and universal adoption means some adults born before their state began screening may never have been tested as newborns, a point we will return to below.
State labs use protein-based methods to analyze the blood sample, looking at the types of hemoglobin present. The most common techniques are high-performance liquid chromatography, capillary electrophoresis, and isoelectric focusing.2PubMed Central. Newborn Screening for Sickle Cell Disease and Other Hemoglobinopathies: A Short Review on Classical Laboratory Methods-Isoelectric Focusing, HPLC, and Capillary Electrophoresis These tests separate the different hemoglobin types in the sample so technicians can see whether the baby has only normal hemoglobin, carries one copy of a variant (trait), or has two copies (disease). One comparison of two common methods found strong agreement between isoelectric focusing and liquid chromatography, with isoelectric focusing recommended as the initial screen because of its higher sensitivity.3Indian Journal of Child Health. Comparative analysis of the role of isoelectric focusing and high-performance liquid chromatography in newborn screening in hemoglobinopathies
How and When Results Reach You
This is the part that trips up many families. The screening happens automatically, but the path results take to reach you depends on your state. A survey of all U.S. newborn screening programs found that every single program provides notification of sickle cell trait status to either a pediatrician or a parent, but the route varies considerably. About half of programs notify only the pediatrician, while roughly 45 percent notify both the pediatrician and the parent directly, and a small fraction notify the parent alone.4PubMed Central. Variability in Notification of Positive Newborn Screening Results for Sickle Cell Trait Across the United States
What this means in practice is that in about half the country, if your baby’s results come back showing only normal hemoglobin, your pediatrician receives that information and may or may not mention it at a well-child visit. Many parents never hear a word about it because normal results are often treated as no news. For an abnormal result, the system is more proactive: the pediatrician is contacted, and in many states the state screening program or a sickle cell center also follows up directly with the family. But “more proactive” still depends on whether your contact information is current and whether you have an established pediatrician on file.
The timeline for getting results usually runs between one and three weeks from birth. Some states have faster turnaround, especially for presumptive positive results that trigger urgent follow-up. If you have not heard anything by your baby’s first well-child visit (usually at three to five days of age), ask the doctor whether newborn screening results have come in. If you switch pediatricians in the first few weeks, make sure the new provider knows to request the screening results from the state lab or the original doctor’s office.
What the Results Actually Mean
Newborn screening results for hemoglobin are reported using letter codes that describe which types of hemoglobin the lab detected. A few common patterns you might encounter on a result sheet:
- FA: Fetal hemoglobin and normal adult hemoglobin. This is a normal result. The baby does not have sickle cell disease or trait.
- FAS: Fetal hemoglobin, normal hemoglobin, and sickle hemoglobin. This indicates sickle cell trait, meaning the baby carries one copy of the sickle hemoglobin gene. Trait is not a disease; it rarely causes health problems on its own.
- FS: Fetal hemoglobin and sickle hemoglobin only, with no normal adult hemoglobin detected. This is a presumptive positive for sickle cell disease (most commonly sickle cell anemia) and requires confirmatory testing.
- FSC: Fetal hemoglobin, sickle hemoglobin, and hemoglobin C. This pattern suggests sickle-hemoglobin C disease, another form of sickle cell disease.
Because all babies have high levels of fetal hemoglobin at birth, the “F” appears first in every newborn result. The fetal hemoglobin gradually declines over the first several months of life, which is partly why confirmatory testing is done later using a different blood draw when the picture of adult hemoglobin types is clearer.
Confirmatory Testing After a Positive Screen
A positive newborn screen is not a final diagnosis. It is a flag that something needs a closer look. When the initial heel-prick sample shows an abnormal hemoglobin pattern, a second blood specimen is collected, usually by venipuncture rather than a heel prick, at a regional lab. In Ohio’s program, for example, this confirmatory draw happens during the first two to four weeks of life and involves additional protein-based tests like capillary zone electrophoresis and, when needed, acid hemoglobin electrophoresis or isoelectric focusing.5PubMed Central. Clinical Utility of Confirmatory Genetic Testing to Differentiate Sickle Cell Trait from Sickle-β+-Thalassemia by Newborn Screening
In some cases, protein-based methods alone cannot distinguish between sickle cell trait and certain forms of sickle cell disease, particularly sickle-beta-plus-thalassemia. When the hemoglobin pattern is ambiguous, genetic testing of the beta-globin and alpha-globin genes can resolve the question. This might include DNA sequencing and copy number analysis to detect deletions or duplications in the globin gene clusters.5PubMed Central. Clinical Utility of Confirmatory Genetic Testing to Differentiate Sickle Cell Trait from Sickle-β+-Thalassemia by Newborn Screening The distinction matters because sickle cell trait generally does not require ongoing treatment, while sickle-beta-plus-thalassemia is a form of sickle cell disease that benefits from early medical management.
Why Preterm Babies Need Extra Attention
If your baby was born early, you should be aware that screening accuracy can be affected. Preterm infants have less mature hemoglobin production, which means they may show hemoglobin patterns that look like sickle cell disease even when the baby only carries the trait. One study found that preterm newborns were significantly more likely to have a false positive screening result. Among premature babies whose initial screen showed a pattern consistent with sickle cell disease (FS), about 23 percent turned out to have only sickle cell trait on confirmatory testing, compared with just 2 percent of full-term infants. For the FC pattern, the false positive rate was even more dramatic: 59 percent for preterm versus 6 percent for term babies.6PubMed. Increased prevalence of false positive hemoglobinopathy newborn screening in premature infants
Blood transfusions add another wrinkle. Premature babies who receive transfusions before their screening sample is collected may have donor hemoglobin mixed into their blood, which can mask the baby’s own hemoglobin pattern entirely. One large screening program in Alberta identified over 5,900 preterm infants in its cohort, of whom 86 had been transfused before their newborn screening sample was drawn.7PubMed Central. The Alberta Newborn Screening Approach for Sickle Cell Disease: The Advantages of Molecular Testing For these babies, repeat testing several months later, once transfused blood has cleared, is standard practice. If your preterm baby spent time in the neonatal intensive care unit and received transfusions, ask the medical team whether the newborn screening sample was collected before or after transfusion, and whether a repeat screen is needed.
What Happens After a Sickle Cell Disease Diagnosis
The whole reason newborn screening exists is to get babies into care before they get sick. Sickle cell disease can cause life-threatening infections in infancy, and the single most important early intervention is starting preventive antibiotics. The American Academy of Pediatrics recommends penicillin prophylaxis for children with sickle cell disease beginning by two months of age and continuing at least through age five.8PubMed Central. Penicillin prophylaxis in children with sickle cell disease This recommendation is based on landmark studies showing that daily penicillin dramatically reduces the risk of severe pneumococcal infection, which historically was a leading killer of young children with sickle cell disease.
Beyond antibiotics, early diagnosis connects families with comprehensive sickle cell care, including vaccinations on an accelerated schedule, regular monitoring with blood counts and organ-function tests, education about fever management (fever in a child with sickle cell disease is a medical emergency), and planning for pain crises. None of this can happen if the family does not know about the diagnosis, which is why the notification process described above matters so much.
Genetic Counseling and the Conversation About Trait
When screening reveals sickle cell trait rather than disease, many parents are relieved but also confused. Trait means the child carries one copy of the sickle hemoglobin gene, which is enough to pass the gene to future children but usually causes no health problems for the carrier. Genetic counseling for these families typically covers the benign nature of the trait, how it is inherited, the fact that at least one parent must also be a carrier, and what the risks look like for future pregnancies or for the child’s own future offspring.9Genetics in Medicine. Systematized Follow-up of Infant Hemoglobinopathy Trait Identified on Newborn Screening Improves Acceptance of Genetic Counseling
The timing of that conversation is also worth thinking about. Researchers have recommended that information about sickle cell trait status be shared with the family at three key points in the child’s life: during the newborn period, in early adolescence, and in later adolescence when reproductive decisions become relevant.10PubMed Central. Genetic Information to Share with Parents when Newborn Screening Reveals the Presence of Sickle Cell Trait The rationale is that parents need the information immediately to understand what the screening result means, but the child also needs age-appropriate education later so they can make informed decisions about partner testing and family planning. A one-time conversation at birth, even if well done, fades from memory and may never reach the child in a meaningful way.
If You Never Got Your Baby’s Results
It is surprisingly common for families to realize months or even years later that they never received newborn screening results. This can happen for several reasons: moving shortly after birth, changing pediatricians, an administrative error in the notification chain, or simply because normal results were never communicated. Here is what you can do:
- Call your pediatrician: Newborn screening results are typically sent to the doctor listed on the birth hospital’s records. Your pediatrician’s office should have these on file, even if they were never discussed with you.
- Contact your state newborn screening program: Every state health department maintains records of newborn screening results. You can usually find contact information by searching your state’s name and “newborn screening program.” Some states allow parents to request results online or by phone; others require a written request.
- Request the birth hospital’s records: The hospital where your baby was born will have documentation of the screening sample being collected, and the results may also be in the hospital’s records system.
Keep in mind that state retention policies for newborn screening records vary. Some states keep the dried blood spot cards for years; others destroy them after a set period. The results themselves are typically retained in the state’s electronic database longer than the physical cards. If you are seeking results for an older child or an adult who was born before their state mandated screening, the records may simply not exist, and a fresh blood test through a primary care provider is the simplest path forward.
Rapid Point-of-Care Tests
Standard newborn screening depends on centralized state laboratories, trained technicians, and reliable sample transport. This infrastructure works well in the United States and other high-income countries, but it presents barriers in resource-limited settings. To address this gap, researchers have developed rapid point-of-care tests that can identify sickle cell disease and trait without any laboratory equipment at all. One such test, called HemoTypeSC, uses specially designed antibodies to detect normal hemoglobin, sickle hemoglobin, and hemoglobin C from less than one microliter of blood, with results in under 20 minutes and no need for electricity or instruments.11PubMed Central. A rapid, inexpensive and disposable point-of-care blood test for sickle cell disease using novel, highly specific monoclonal antibodies
These rapid tests are not replacements for the full newborn screening panel, which checks for many other conditions beyond sickle cell disease. But they offer a practical solution for situations where centralized screening is unavailable or where someone needs a quick answer, such as in field clinics, community health settings, or regions without functioning lab networks. They are also useful for re-testing older children and adults who were never screened as newborns.
Screening Outside the United States
If your baby was born outside the U.S., the availability of sickle cell screening depends heavily on where you are. Many high-income countries, including the United Kingdom, France, and parts of Canada, have established newborn screening programs for hemoglobin disorders. But the burden of sickle cell disease falls disproportionately on sub-Saharan Africa, which accounts for roughly 75 percent of the global prevalence of the disease yet has not been able to implement universal newborn screening.12PubMed Central. Newborn screening initiatives for sickle cell disease in Africa Barriers include limited laboratory infrastructure, inconsistent policy frameworks, and challenges in linking screened babies to the ongoing care that makes early diagnosis worthwhile.
Pilot programs in several African countries have demonstrated that newborn screening is feasible and saves lives when paired with comprehensive follow-up care. The rapid point-of-care tests described above are playing an increasingly important role in these programs, allowing screening in communities far from centralized labs. If you had a baby in a country without universal screening, or if you immigrated after your child’s birth, talk to your child’s doctor about getting a hemoglobin test done. A simple blood draw at any age can determine whether your child has sickle cell disease or carries the trait.
Testing Older Children and Adults Who Missed Newborn Screening
Not everyone born before universal screening was adopted, or born in a country without it, has gone through life unscreened and unaffected. Many people with sickle cell trait never know they carry it, and some people with milder forms of sickle cell disease, like sickle-hemoglobin C disease or sickle-beta-plus-thalassemia, can reach adulthood without a clear diagnosis, particularly if their symptoms were attributed to other causes.
If you were never screened, or if you are unsure of your status, your primary care doctor can order a hemoglobin electrophoresis or a complete blood count with hemoglobin fractionation. These are standard lab tests available through any clinical laboratory. Results typically come back within a few days. There is no age limit on testing, and knowing your status is particularly useful before planning a pregnancy, since two carriers of sickle cell trait have a one-in-four chance of having a child with sickle cell disease with each pregnancy.
Some people first learn about their carrier status through other channels. College athletes in the United States, for example, are often tested for sickle cell trait as part of pre-participation physicals. Military recruits may also be screened. But these ad hoc encounters are not a substitute for systematic screening, and they create their own set of questions about what a positive trait result means for physical activity and health, questions best addressed with a knowledgeable provider rather than a coach or recruiter.