Infections during pregnancy may cause autism, study finds

A new study suggests that women infected with genital herpes during pregnancy are at a higher risk for having a child with autism.

Women who had active infections early in pregnancy were twice as likely to have a child with an autism spectrum disorder as women who did not, according to the researchers.

“We believe the mother’s immune response to HSV-2 (herpes simplex type 2) could be disrupting fetal central nervous system development, raising risk for autism,” Milada Mahic, a researcher at Columbia University who led the research team, told NBC News.

Researchers believe the woman’s immune response to the infection (the inflammation) may be causing the damage – not the virus itself.

The study tested women for immune responses to four viruses known to cause birth defects, including rubella, herpes simplex type 1 (cold sores) and herpes simplex type 2 (genital herpes).

Women with high levels of antibodies to genital herpes midway through their pregnancies were twice as likely to have a baby with autism. None of the other viruses seems to affect autism risk, according to the researchers.

Marissa Harshman

Marissa Harshman

I'm the health reporter for The Columbian newspaper in Vancouver, Wash. I started at The Columbian -- my hometown newspaper -- in September 2009. Reach me at or 360-735-4546.

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