A combination blood test measuring three proteins—APOC1, LMNA, and TPM4—correctly identified fetal heart problems 98% of the time in a 2026 study of 108 older pregnant women, according to Gram Research analysis. The combined test achieved 91% overall accuracy, significantly outperforming individual protein measurements, though researchers emphasize that external validation is needed before clinical use.
Researchers found that three specific proteins in a pregnant woman’s blood could help predict whether her baby will have heart problems. In a study of 108 older pregnant women (age 35 and up), scientists discovered that measuring APOC1, LMNA, and TPM4 proteins together was very accurate at spotting fetal heart abnormalities. When combined into one test, these three markers correctly identified heart problems 98% of the time. According to Gram Research analysis, this discovery could help doctors catch heart issues earlier in pregnancy, giving families more time to prepare and plan care.
Key Statistics
A 2026 cohort study of 108 pregnant women age 35 and older found that a combined blood test measuring APOC1, LMNA, and TPM4 proteins achieved 98.49% sensitivity for detecting fetal cardiac abnormalities.
According to research reviewed by Gram, the three-protein combination test had an overall accuracy (AUC) of 0.906 for predicting fetal heart problems, significantly superior to any single protein marker alone.
In the 2026 study of 108 older pregnant women, APOC1 levels were elevated in mothers carrying babies with heart problems, while LMNA and TPM4 levels were decreased, with all differences statistically significant (P<0.05).
The combined prediction model for fetal cardiac abnormalities showed 76.19% specificity in correctly identifying normal pregnancies among the 108 women studied in 2026.
The Quick Take
- What they studied: Whether three specific blood proteins can predict if a baby will have heart problems when the mother is 35 or older
- Who participated: 108 pregnant women age 35 and older who were at risk for having babies with heart problems. 42 had normal pregnancies, and 66 had babies with heart abnormalities.
- Key finding: A combination blood test using three proteins (APOC1, LMNA, and TPM4) correctly identified fetal heart problems 98% of the time, with an overall accuracy of 91%
- What it means for you: If you’re 35 or older and pregnant, this test could potentially help doctors spot heart problems in your baby earlier. However, more research is needed before it becomes a standard screening tool.
The Research Details
Researchers looked back at medical records from 108 pregnant women age 35 and older who had concerns about their baby’s heart health. They divided the women into two groups: those whose babies had normal hearts (42 women) and those whose babies had heart problems (66 women). All women had blood samples taken between 18-24 weeks of pregnancy. The scientists measured 10 different heart-related proteins in the blood and found that three of them—APOC1, LMNA, and TPM4—showed the biggest differences between the two groups. They then created a prediction model using these three proteins to see how well they could identify which babies would have heart problems.
This approach is important because it looks for early warning signs in the mother’s blood rather than relying only on ultrasound images. Finding a simple blood test that can predict heart problems could help doctors catch issues earlier and give families more time to prepare. For older mothers, who have higher risks of complications, this kind of early detection could be especially valuable.
This study looked at real patient data, which is a strength. However, it was a retrospective study (looking backward at existing records) rather than following new patients forward. The study included a moderate sample size of 108 women, which is reasonable but not huge. The researchers adjusted their findings for folate supplementation, which shows they considered other factors that might affect results. The study authors note that external validation—testing the findings in other groups of women—is needed before this test could be used in regular clinical practice.
What the Results Show
When comparing women whose babies had normal hearts to those whose babies had heart problems, the researchers found clear differences in all three proteins. APOC1 levels were higher in mothers of babies with heart problems, while LMNA and TPM4 levels were lower. These differences were statistically significant, meaning they weren’t likely due to chance. When the researchers combined all three proteins into one prediction model, the test was remarkably accurate. It correctly identified 98.49% of babies with heart problems (sensitivity) and correctly identified 76.19% of babies with normal hearts (specificity). The overall accuracy of the combined test was 91%, which was better than using any single protein alone.
The study also found that as fetal heart abnormalities became more severe, the pattern of protein levels became more pronounced. APOC1 levels increased with severity, while LMNA and TPM4 levels decreased further. This suggests these proteins might not just predict whether a problem exists, but also how serious it might be. The researchers confirmed that these three proteins remained strong predictors even after accounting for whether mothers had taken folate supplements during pregnancy.
This research builds on earlier work showing that blood proteins can predict pregnancy complications. Previous studies have identified various biomarkers for different pregnancy problems, but this appears to be one of the first to focus specifically on these three proteins for fetal heart abnormalities in older mothers. The high accuracy rate (91%) is promising compared to other biomarker studies, though direct comparisons are limited because this is a relatively new approach.
The biggest limitation is that this study only looked at women who were already suspected of having fetal heart problems—it didn’t test whether the blood test could identify problems in women with no symptoms. The study was also done in one location with one population, so the results might not apply to all women everywhere. The researchers used historical data rather than following new patients, which can introduce bias. Most importantly, the authors themselves note that this test needs to be validated in other groups of women before it could be used in regular medical practice. The study also didn’t explain exactly why these three proteins are connected to heart problems, which limits our understanding of the mechanism.
The Bottom Line
If you’re 35 or older and pregnant with concerns about your baby’s heart health, discuss this research with your doctor. While the test shows promise, it’s not yet standard practice. Continue with recommended prenatal screening, including ultrasounds. This blood test might become an additional tool in the future, but more research is needed first. Confidence level: Moderate—the findings are promising but need external validation.
Pregnant women age 35 and older, especially those with risk factors for fetal heart problems or a family history of heart disease. Women who have had previous pregnancies with heart abnormalities should also be aware of this research. Doctors and maternal-fetal medicine specialists should follow this research as it develops. This research is less relevant for younger pregnant women without risk factors, though it could eventually benefit them too.
If this test becomes available, results would likely be available within days to weeks, similar to other blood tests. Any benefits would depend on how early the test is done (ideally 18-24 weeks as shown in this study) and what interventions are available for the detected problems. Some heart conditions can be managed during pregnancy or prepared for at birth, while others may require immediate surgery after delivery.
Frequently Asked Questions
Can a blood test predict if my baby will have heart problems?
A new blood test measuring three proteins (APOC1, LMNA, and TPM4) showed 98% accuracy in identifying fetal heart problems in a 2026 study of 108 older pregnant women. However, it’s not yet available for routine use and needs further validation.
What are APOC1, LMNA, and TPM4 and why do they matter in pregnancy?
These are three proteins found in blood that appear to be connected to fetal heart development. When levels are abnormal, they may signal heart problems in the baby. The study found that measuring all three together is more accurate than checking them individually.
Should I get this blood test if I’m over 35 and pregnant?
Currently, this test is not standard practice. Discuss it with your doctor if you have risk factors for fetal heart problems. Continue with recommended prenatal screening like ultrasounds. This test may become available in the future after more research confirms its usefulness.
How early in pregnancy can this test detect heart problems?
In the study, blood samples were collected between 18-24 weeks of pregnancy. This timing allows for early detection, giving families time to prepare and plan care with their medical team.
What should I do if I’m worried about my baby’s heart health?
Talk to your obstetrician or maternal-fetal medicine specialist. They can recommend appropriate screening, including ultrasounds and possibly genetic counseling. Stay informed about new research like this blood test, but rely on your doctor’s guidance for current best practices.
Want to Apply This Research?
- Track your blood test dates and results (APOC1, LMNA, TPM4 levels if available) alongside ultrasound findings and doctor visits to monitor fetal heart health progression
- Set reminders for prenatal appointments and blood work, log any symptoms or concerns about fetal movement, and maintain detailed records to share with your healthcare team
- Create a pregnancy health timeline documenting all screening tests, blood work results, and ultrasound findings; compare trends over time and discuss patterns with your doctor at each visit
This article discusses research findings and is not medical advice. The blood test described in this study is not yet available for routine clinical use and requires further validation. Pregnant women, especially those 35 and older or with risk factors for fetal heart problems, should consult with their obstetrician or maternal-fetal medicine specialist about appropriate screening options. All prenatal care decisions should be made in consultation with qualified healthcare providers who understand your individual medical history and circumstances. This research is preliminary and should not replace standard prenatal care and ultrasound screening.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.