Does COVID during pregnancy “cause” neurodevelopmental disorders like autism? A recent study suggests there is a possible link, but more studies are needed to know for sure.
There’s been a lot in the news lately about pregnancy and risks of neurodevelopmental disorders, including recent claims that Tylenol/Paracetamol in pregnancy is associated with a higher risk of autism (note: there is no evidence to support this claim at the moment). So we were struck by a recent paper that found an association between COVID during pregnancy and neurodevelopmental disorders in 3-year-old children.
So is it true? Does COVID during pregnancy “cause” neurodevelopmental disorders like autism?
Let’s take this step by step. In this study, the authors looked at electronic medical record data for all live births at 8 Boston-area hospitals during the period of March 1, 2020 until March 1, 2021. They then separated the births into two groups.
Infants who were born to those who had COVID during pregnancy were put in one group and infants who were born to those who did not have COVID during pregnancy were put in another group. During the study period all people hospitalized were screened for COVID-19, so this made it really easy for the authors to verify infection status.
The authors then looked at the medical records of these infants from birth to 36 months of age for diagnoses of developmental delay.
The results? More children in the exposed group (i.e. their parent had COVID during pregnancy) were diagnosed with developmental delay (16.7%) compared to the unexposed group (9.7%).
As always, there were some other variables (also known as confounders) that could be contributing to these diagnoses, so in the analysis, the authors controlled for several factors, including maternal age, preterm birth, and socioeconomic factors. All of these have been previously associated with differences in developmental delay
After controlling for the above confounders, this comes out to a 1.29 adjusted odds ratio, or a finding that those exposed to COVID in the womb had an almost 30% greater odds of developing neurodevelopmental diagnoses than those not exposed. In other words, after controlling for other possible causes of developmental delay, they found that babies exposed to COVID-19 in the womb were still more likely to be diagnosed with a developmental disorder in the first 36 months of life than those who were not exposed to infection.
So what do we do with this information? This study suggests that exposure to COVID-19 in the womb is associated with developmental delay based on diagnosis in the first three years of life. There’s a major caveat here. This study looks at cases early in the pandemic, when almost no one was vaccinated and many people were just getting infected for the first time. The results today might look much different because the immune response to getting infected the first time is often different from subsequent times and may impact the fetus differently.
Bottom Line: Does COVID “cause” neurodevelopmental delays? This study (and others to date) cannot answer that question because they’re only looking at associations. While we need more data, this is another possible reason to minimize the risk of a COVID-19 infection through tools like masking, vaccination and ventilation.
