The question of whether COVID-19 infection during pregnancy poses risks to a child’s developing brain has been a significant concern since the start of the pandemic. While initial observations were somewhat reassuring, more recent research suggests a potential link between maternal COVID-19 and an increased risk of neurodevelopmental conditions in offspring.
Historically, certain infections during pregnancy have been known to impact fetal development. Rubella, cytomegalovirus (CMV) infection, and toxoplasmosis are well-established examples where preventative measures are taken due to the potential for harm. The Zika virus, once considered relatively benign, was later found to cause delayed brain development and microcephaly in fetuses exposed during the first trimester of pregnancy.
Early in the COVID-19 pandemic, data was limited, and the virus itself hadn’t significantly mutated. Initial findings suggested that the impact of COVID-19 on pregnancy wasn’t dramatically different from uninfected pregnancies, although a higher frequency of pre-eclampsia was observed in infected mothers. Birth weights and Apgar scores were generally comparable. However, researchers acknowledged that COVID-19 could potentially impact fetal development, particularly in mothers with pre-existing conditions like obesity, diabetes, hypertension, or lung disease.
More recent studies have begun to clarify the potential risks. Researchers now understand that maternal infection, even if the fetus isn’t directly infected, can influence fetal development. This is thought to occur through activation of the mother’s immune system and subsequent inflammation at the placenta and within the fetus itself. These inflammatory processes are suspected of disrupting brain development, potentially manifesting as neurodevelopmental disorders later in life, such as autism spectrum disorder, attention deficit hyperactivity disorder, cognitive deficits, or even schizophrenia.
A study by A.G. Edlow, and V.M. Castro analyzed data from to , examining 18,355 children, including 883 born to mothers with a positive RT-PCR test during pregnancy. This research demonstrated an increased risk of neurodevelopmental disorders in children whose mothers had COVID-19 during pregnancy. The disorders, encompassing psychomotor, language, and learning difficulties, were more frequently observed in boys and tended to appear before the age of one year, with the difference diminishing by 18 months.
Another study, led by L.L. Shook, examined health data up to age three for 18,124 children born during the same period, including 861 whose mothers were infected with SARS-CoV-2 during pregnancy. The results showed that 16.3% of children exposed to the infection were diagnosed with a neurodevelopmental condition by age three, compared to 9.7% of those not exposed. This difference was particularly pronounced in boys and when the maternal infection occurred during the third trimester of pregnancy.
While these studies suggest a possible link between COVID-19 and developmental disorders, researchers emphasize that more investigation is needed. Longer-term, prospective studies are crucial to establish a definitive causal relationship. It’s also important to consider the potential role of the immune response to infection, rather than the infection itself, in influencing fetal development.
This raises the question of whether vaccination against COVID-19 during pregnancy could have similar effects. However, several factors suggest that the immune response generated by vaccination is likely different from that triggered by a natural infection. Vaccine-induced immune responses are typically more limited in intensity and duration, as the antigens are quickly eliminated. Extensive literature reviews by organizations like the World Health Organization (WHO) have found no evidence of a causal link between vaccines and autism.
In fact, several vaccines are considered safe and even beneficial during pregnancy, providing protection to both the mother and the developing child through antibody transfer. Importantly, vaccination can be administered *before* pregnancy, mitigating potential risks during gestation.
Recent experimental research in hamsters – chosen for their susceptibility to SARS-CoV-2 and the similarity of their placenta to the human placenta – supports the idea that placental inflammation plays a key role in fetal developmental issues. Researchers at the Rega Institute in Leuven found that inflammation of the placenta caused intrauterine growth restriction in the offspring of infected females. While the mothers experienced pneumonia and weight loss, the virus itself wasn’t transmitted to the embryos. However, viral RNA was detected in the placentas, which exhibited lesions and increased levels of inflammatory markers. This placental inflammation and its impact on fetal growth could be prevented by anticoagulant treatment and preventative vaccination.
The researchers acknowledge limitations to their study, noting that fetal growth retardation isn’t always correlated with long-term physical or mental developmental disorders. However, they believe their work identifies placental inflammation as a potential therapeutic target in cases of maternal COVID-19 infection.
These findings highlight the importance of preventing COVID-19 infection during pregnancy, and underscore the need for continued research to fully understand the potential long-term effects on children born to mothers infected during the pandemic.
