Wednesday, January 27, 2010

Pregnancy + flu might be bad

Yesterday in Medical News Today there was an article that talked about a new study showing a possible relation between material infection and changes in brain development in her offspring.

Expectant Mom's Flu Exposure Stunts Baby's Brain Development
For expectant mothers, catching even a mild case of the flu could stunt brain development in their newborns, according to a new study conducted in rhesus macaques.
The study was a controlled experiment with 19 pregnant monkeys were 12 were exposed to a strain of the seasonal flu while the other 7 were not.  The results were notable -
Birth weight and gestation length were not affected, nor were infant neuromotor, behavioral, and endocrine responses. However, magnetic resonance imaging analyses revealed significant reductions in cortical gray matter in flu-exposed animals. Regional analyses indicated the largest gray matter reductions occurred bilaterally in cingulate and parietal areas; white matter was also reduced significantly in the parietal lobe.
In other words, the offspring of the monkey's that were exposed to the flu had a 4 - 7 percent decrease in the number of cells in the cerebral cortex and these differences may be permanent.  What is interesting is that it doesn't appear that the flu virus that caused the problems but rather the mother's response to it -
Maternal infections were mild and self-limiting. At birth, maternally derived influenza-specific immunoglobulin G was present in the neonate, but there was no evidence of direct viral exposure.
 The authors elaborate in the Medical News Today article, saying -
Coe and his colleagues ... speculate that the flu infection affects the developing fetus indirectly through the mother's inflammatory and immune response to the virus. In primates, including humans, the inflammatory response is more pronounced in the third trimester of pregnancy, the time when the animals in the new study were infected. 
This is not the first piece of research to show that a pregnant women's immune response can effect the developing fetus and I am sure it is not going to be the last.   The kicker is the authors suggestion based on the research -
The take-home message of the research, Coe argues, has compelling public health implications: Pregnant women or those who expect to conceive during flu season should be vaccinated. Flu vaccinations are widely regarded in the medical community and by the U.S. Centers for Disease Control (CDC) as safe for pregnant women.
 I know that this isn't necessarily bad advice. But, I have to point out, what exactly is it that vaccines do if not stimulate an immune response?  The reaction might not be as strong as it would be to the full flu but at the same time the current research doesn't deal with the strength of the immune response, just the fact that there is a response.

Sounds like more research is needed (what else is new).

No comments:

Post a Comment