Researchers at the Weizmann Institute of Science, have explored the question of how a virus infection harm pregnant mother’s baby’s brain in mice and discovered that a viral infection during pregnancy may harm baby’s brain even if the fetus is not infected with the virus itself.
This is a significant discovery, for, scientists don’t know yet how a viral infection during pregnancy increases the risk of number of diseases including autism, schizophrenia, and and neuropsychiatric disorders.
The team of researchers led by Prof. Michal Schwartz infected pregnant mice with a synthetic RNA molecule that mimics an infection caused by RNA viruses. The latter belong to a large family of viruses that induce diseases such as flu, measles, Ebola and COVID-19. When the mouse pups were born, it turned out that their brain’s immune cells, the microglia, were adversely affected and showed abnormal behavior.
Scientists exposed the pregnant mice to the virus-mimicking molecules but at the same time treated them with antibodies that neutralize the interferon-beta. The treatment reduced the adverse effect on the microglia of the pups, suggesting that this effect was due to the interferon-beta.
Next, to double check this conclusion, the scientists – instead of infecting the pregnant mice with the virus-mimicking molecules – injected them with the interferon-beta. In this case, too, the microglia of the newborn pups displayed similar abnormal functioning. Moreover, the pups themselves were later shown to behave abnormally, in a manner similar to the one exhibited in neuropsychiatric disorders, and they were more prone to stress than those born to mothers that had not been exposed to high levels of interferon-beta.
These results show that even when the fetus is not directly exposed to a virus found in the mother’s body, the microglia in the fetal brain might be damaged by the interferon-beta that the mother secretes in large amounts in response to the viral infection.
“Further research may find ways of protecting the fetus from the mother’s response to the virus – that is, from the interferon that rises during viral infection,” Schwartz says. “In the meantime, pregnant women would do well to exercise caution, so as to avoid becoming infected with viruses during pregnancy.”
Infections in pregnancy that may affect your baby
According to the pregnancy and baby guide of the NHS, following following infections can cause problems in pregnancy:
Chickenpox: Chickenpox infection in pregnancy can be dangerous for both mother and baby, so it’s important to seek advice early if you think you may have chickenpox.
CMV: CMV infections are common in young children, but it can cause many problems for unborn babies, such as hearing loss, visual impairment or blindness, learning difficulties and epilepsy. CMV is particularly dangerous to the baby if the pregnant mother has not had the infection before.
Group B streptococcus: In women, the bacteria are found in the intestine and vagina.
GBS infection of the baby is more likely if:
- you go into premature labour (before 37 weeks of pregnancy)
- your waters break early
- you have a fever during labour
- you currently carry GBS
Hepatitis B: The virus is spread by having sex with an infected person without using a condom, and by direct contact with infected blood. If you have hepatitis B or are infected during pregnancy, you can pass the infection on to your baby at birth.
Hepatitis C: Hepatitis C can also be transmitted by receiving medical or dental treatment in countries where hepatitis C is common and infection control may be poor, or by having sex with an infected partner. If you have hepatitis C, you may pass the infection on to your baby, although the risk is much lower than with hepatitis B or HIV.
