Genital Herpes In Pregnancy And Risk Of Autism In Offspring

According to a recent research, the offspring of a woman having genital herpes in pregnancy has increased risk of developing autism spectrum disorder, ASD. The research was conducted by Milada Mahic from Norwegian Institute of Public Health in Norway and Center for Infection and Immunity, and his colleagues whereas the findings were published in the journal called mSphere.

Genital herpes has high prevalence worldwide with approximately 417 million people falling victim to genital herpes caused by herpes simplex virus 2 (HSV2). It is a very common sexually transmitted disease (STD) with about 10-20% of the cases reported in people who have been previously diagnosed with the condition.

The incidence of HSV-2 infection is far greater in women in contrast to men. Approximately 20.3% women in USA between the age group of 14 and 49 gets infected by HSV2 in comparison to 10.6% men.

Mahic and colleagues suggested that in individuals with HSV2 infection, the virus may stay in a dormant state in the nerve cells. The flare-ups may result from the reactivation of virus that may happen anytime. The flare-ups may reduce in frequency with the development of immunity against the virus. However, this happens with time.

Risk Of Autism In Babies Born To Mothers With Genital Herpes

New research work has shown a correlation between the response of the immunity against various infections during pregnancy and high risk of ASD (autism spectrum disorder) in the offspring. Mahic and colleagues conducted a study that showed results similar to those of such researches.

Immune Response And Disruption Of Fetal Neurodevelopment

The study of Mahic and colleagues was based on the analysis of 875 blood samples collected from the mothers enrolled in the ABC study (Autism Birth Cohort). 412 of these women were mothers to ASD children whereas 463 of them were mothers to non-ASD children. The blood sample collection was done during the 18^th week of pregnancy and during the delivery of the baby. The analysis was based on the detection of antibodies levels in response to following five pathogens:

• Toxoplasma gondii
• Rubella virus
• Cytomegalovirus
• HSV-1
• HSV-2

After thorough assessment of the blood samples Mahic and colleagues found out that mothers who exhibited elevated antibodies levels in response to HSV-2 had twice as greater risk of giving birth to an offspring with ASD. The elevated antibodies levels in response to the remaining four pathogens were not considered to be of any potential danger for causing autism in offspring.

The researchers suggested that 18^th week of pregnancy is the time marked for the rapid development of the nervous system of the fetus. During that time, the response of the mother’s immune system to HSV2 may disrupt the development of the fetal nervous system which may automatically contribute to autism in the offspring.

The researchers also reported that this strong correlation between the elevated antibodies level in response to HSV2 and high risk of autism in offspring was only confined to boys. But since the study was limited to a small number of ASD females, therefore it was difficult for the researchers to speculate about the finding being sex-specific. Nevertheless, they suggested that ASD is more common in boys than girls.

References

• Mahic, M., Mjaaland, S., Bøvelstad, H. M., Gunnes, N., Susser, E., Bresnahan, M., ... & Reichborn-Kjennerud, T. (2017). Maternal Immunoreactivity to Herpes Simplex Virus 2 and Risk of Autism Spectrum Disorder in Male Offspring. mSphere, 2(1), e00016-17.
• Racicot, K., & Mor, G. (2017). Risks associated with viral infections during pregnancy. The Journal of clinical investigation, 127(5), 1591-1599.