Women with genital herpes infection early in pregnancy are twice as likely to bear a child with autism compared with other women.
Autism Spectrum Disorder
Findings of a new research released on Wednesday show that pregnant women with herpes simplex 2, the virus responsible for most cases of genital herpes infections had higher risk of giving birth to kids with autism spectrum disorder, a development condition marked by difficulty in social interaction as well as repetitive behaviors and interest.
Autism symptoms tend to emerge when children reach 2 to 4 years old albeit animal studies suggest that the neurodevelopmental disorder may start during early brain development.
About one in five women in the U.S. has HSV-2. The virus is highly contagious and lifelong infection, which is usually spread through sex, is lifelong. Following an initial outbreak, the virus lives in near nerve cells and is often inactive. Flare-ups become less frequent as the body builds up its immunity to the virus.
Genital Herpes Virus And Autism
Viruses such as Zika and rubella are known to infect the developing brain of an unborn child and possibly cause brain damage but things are a little different when it comes to autism.
Infectious disease expert Ian Lipkin, from Columbia University, said that people tend to associate viruses going into tissues and damage cells but this is not the same with autism.
Lipkin said that it is the inflammation, or the pregnant woman's immune response, that causes the damage. It is possible that inflammatory chemicals such as cytokines cross the placenta and affect the developing brain of the fetus.
Study researcher Milada Mahic, also from Columbia University said that the mother's immune response to HSV-2 may possible disrupt the development of the fetal central nervous system which raises risk for autism.
For the study, Lipkin and colleagues compared 442 mothers of children with autism and 464 women whose babies do not have autism.
The researchers tested the women's immune responses to four viruses that are known to cause birth defects namely cytomegalovirus, rubella, herpes simplex 1, which causes cold sores, and HSV-2.
The researchers found that the women with high levels of antibodies to HSV-2 midway through pregnancy have twice the risk of having a baby that would later be diagnosed with autism. The other viruses did not seem to affect autism risk though.
The increased levels of antibodies to HSV-2 hint of either a recent primary infection or a reactivation of a latent infection.
Autism And Inflammation During Pregnancy
The study, which was published in the journal mSphere offers another evidence showing that inflammation during pregnancy may have effects on the brain of a developing fetus. In an earlier study, researchers found a link between polycystic ovary syndrome (PCOS) and having children born with ASD.
"These findings provide support for the hypothesis that gestational infection may contribute to the pathogenesis of autism spectrum disorder and have the potential to drive new efforts to monitor women more closely for cryptic gestational infection and to implement suppressive therapy during pregnancy," the researchers wrote in their study.