Pregnant women, like everyone, get sick. And like everyone else, their bodies try to fight infection and, importantly, keep it from reaching the growing fetus.
If the mother’s immune system successfully defeats the virus before the developing baby is exposed or if the virus never crosses the placenta, is harm averted?
Counterintuitively, this protective response may be a risk factor for some neurological conditions in the baby later on.
This is the question that researchers, including me, have been probing at the neurodevelopment lab at the University of California, Davis. Research suggests that the mother’s defensive immune response to an infection, for instance, alone is sufficient to cause lifelong changes in brain architecture and function and in behavior in the offspring. This response is a strong risk factor for brain disorders like autism and schizophrenia.
A new study that has come out indicates that:
the degree and duration of Maternal Immune Reaction (MIA) determines the risk of a child being diagnosed with a brain disorder later on, like autism or schizophrenia. And infections aren’t the only cause of MIA. For example, an increased risk is also associated with psychological stress during pregnancy, which triggers a similar immune activation.
If this is true, they should find that babies born in november are least likely to be sz. Because pregnancy occured in march and ended in november hence avoiding flu-season. They should be able to replicate results.
There is a seasonality of birth factor in schizophrenia risk - but its made more complex by both nutritional factors (mothers tend to eat better with more fresh vegetables etc. during the summer when they are available) and also sunlight / vitamin D exposure. Here is more about this: