Researchers found that some pregnant women have special proteins in their blood called folate receptor alpha autoantibodies (FRAA) that may be linked to autism in their babies. In this study, when mothers had these proteins AND their ultrasound showed a thicker neck area in the fetus, all four of their children were later diagnosed with autism. This discovery is exciting because it might help doctors identify autism risk very early in pregnancy, before a baby is born. The findings suggest that the mother’s immune system may play a role in autism development, and doctors might be able to help prevent it with special vitamin supplements.

The Quick Take

  • What they studied: Whether a special blood test during pregnancy can predict if a baby will develop autism, by looking for immune proteins in the mother’s blood combined with ultrasound findings
  • Who participated: 3,600 pregnant women who had first-trimester ultrasounds; 27 had unusual findings; 11 had negative genetic tests and were followed to see if their children developed autism
  • Key finding: All 4 babies whose mothers had the special immune proteins (FRAA) and thickened neck tissue on ultrasound were diagnosed with autism by age 3, compared to only 1 of 7 babies without these markers
  • What it means for you: This research suggests doctors may soon be able to identify autism risk during pregnancy using a simple blood test combined with ultrasound. However, this is early research with a small number of cases, so more studies are needed before this becomes a standard screening tool.

The Research Details

Researchers looked at ultrasound images from 3,600 pregnant women in their first three months of pregnancy. They found 27 babies with an unusual thickening in the neck area (called nuchal translucency). These 27 pregnancies were studied more carefully with genetic tests to look for chromosome problems or genetic changes. The mothers’ blood was tested for special immune proteins called FRAA. Eleven of these pregnancies had normal genetic test results, so researchers followed these families and checked the children’s development up to age 3 using standard autism assessment tools.

This approach combined three pieces of information: the ultrasound finding, the genetic testing, and the blood test for immune proteins. By following the children over time and using established diagnostic criteria, researchers could see which children developed autism and whether the blood test and ultrasound findings predicted this outcome.

The study is relatively small but intensive, meaning researchers gathered detailed information about each case rather than studying large numbers of people with less detail.

This research approach is important because it looks for early warning signs before a baby is born. Finding markers during pregnancy could allow doctors to monitor children more closely after birth or potentially offer early interventions. The combination of ultrasound findings and blood tests is more powerful than either test alone, which makes the findings more meaningful.

This is a preliminary study with a small number of cases (only 4 FRAA-positive children), so the results are interesting but not yet definitive. The researchers used established diagnostic tools (ADOS-2 and DSM-5 criteria) to confirm autism diagnoses, which strengthens the findings. However, larger studies are needed to confirm whether this blood test actually predicts autism risk in the general population. The fact that all 4 FRAA-positive cases developed autism is striking but could be due to chance with such small numbers.

What the Results Show

Among the 11 pregnancies with normal genetic tests, 4 mothers had the special immune proteins (FRAA) in their blood. All 4 of these children were later diagnosed with autism by age 3. In contrast, only 1 of the 7 children whose mothers did not have these immune proteins was diagnosed with autism. This means that in this small group, having the immune proteins was associated with a much higher autism risk.

The babies with FRAA-positive mothers all had markedly thickened neck tissue on ultrasound (3.5 mm or thicker), but their genetic tests came back normal. This suggests the thickening was not caused by chromosome problems or genetic mutations, but possibly by the mother’s immune system affecting the developing baby.

Interestingly, the immune proteins were found not only in the mothers’ blood but also in the babies’ blood after birth. This suggests the babies were exposed to these proteins during pregnancy, which may have affected their brain development.

The persistence of FRAA in both maternal and newborn blood samples suggests ongoing immune activity during pregnancy. The fact that genetic testing was negative in FRAA-positive cases indicates this is not a traditional genetic disorder but possibly an immune-mediated condition. The researchers suggest that folinic acid (a form of vitamin B) supplementation might help prevent autism in these cases, though this has not yet been tested.

Previous research has suggested that the mother’s immune system may play a role in autism development. This study adds to that evidence by identifying a specific immune protein that may be involved. The finding that increased neck thickness on ultrasound might indicate autism risk is new and builds on earlier observations that some autism cases have subtle physical markers visible before birth.

The biggest limitation is the very small number of cases—only 4 children with FRAA-positive mothers. With such small numbers, the results could be due to chance. The study only included pregnancies with markedly increased neck thickness, so we don’t know if FRAA is important in autism cases without this ultrasound finding. The study was conducted at a single medical center, so results may not apply to all populations. Longer follow-up would be helpful to confirm autism diagnoses and see if the condition remains stable over time.

The Bottom Line

This research is too preliminary to recommend routine screening at this time. However, if a pregnant woman has a thickened fetal neck on ultrasound and tests positive for FRAA, closer monitoring of the child’s development after birth may be warranted. Discussing these findings with a genetic counselor or maternal-fetal medicine specialist would be appropriate. The suggestion about folinic acid supplementation is speculative and should not be pursued without medical guidance.

Pregnant women with ultrasound findings of increased fetal neck thickness should be aware of this research. Parents of children with autism may find this interesting for understanding potential causes. Healthcare providers specializing in pregnancy, autism, or immunology should follow this research. This does NOT apply to all pregnancies—only those with specific ultrasound findings.

Autism diagnosis typically occurs between ages 18-36 months, which is when the children in this study were assessed. If this blood test becomes a screening tool, benefits would come from early identification and intervention rather than prevention, with effects potentially visible over months to years of early intervention.

Want to Apply This Research?

  • If a user has received FRAA testing during pregnancy, they could track their child’s developmental milestones (first words, social interactions, play behaviors) monthly from birth to age 3 using the app’s milestone tracker, comparing against typical development timelines.
  • Users could set reminders to observe and log specific social and communication behaviors weekly (eye contact, response to name, pointing, sharing interests) to create a detailed developmental record to share with healthcare providers.
  • Establish a long-term developmental tracking system from birth through age 3, with monthly check-ins on communication, social interaction, and play skills. Create alerts for developmental concerns that warrant professional evaluation. Maintain a shareable report for pediatricians and developmental specialists.

This research is preliminary and based on a very small number of cases. It should not be used to make medical decisions without consulting with a healthcare provider. The findings suggest a potential association but do not prove cause and effect. Pregnant women with concerns about fetal development should discuss any ultrasound findings with their obstetrician or maternal-fetal medicine specialist. FRAA testing is not currently a standard screening test and should only be considered under medical supervision. This information is for educational purposes only and does not replace professional medical advice.