Mercury Exposure in Womb Not linked with Autism-Like Behavior

Eating fish that have low levels of mercury during pregnancy does not increase the risk of autism development in the child, a new study reported. 

Previous research has shown that eating fish helped boost brain development in babies. But, it is also known that high levels of mercury present in these fish could increase risk of neurological disorders, leaving women worried about their fish intake during pregnancy

The Dietary Guidelines for Americans also recommends that women, pregnant or breastfeeding, eat at least 8 ounces but no more than 12 ounces of seafood each week but avoid certain types of fish that are high in mercury. Fish to be avoided include shark, swordfish, king mackerel, and tilefish along with any uncooked fish.

The new study shows that exposure to low levels of mercury in the womb may not increase autism risk in children.

"This study shows no evidence of a correlation between low level mercury exposure and autism spectrum-like behaviors among children whose mothers ate, on average, up to 12 meals of fish each week during pregnancy," said Edwin van Wijngaarden, from the University of Rochester Medical Center's (URMC) and lead author of the study.

The data for the study came from the The Seychelles Child Development Study that has looked into the effects of fish consumption on childhood brain development since the mid-1980s.

The present study was based on information from over 1,700 children, teens and young adults along with their mothers.

Researchers determined the mercury level during pregnancy by analyzing hair samples collected when the mothers in the study were pregnant. Next, the study participants were given questionnaires to determine whether they had signs of autism.

The study found no link between mercury levels during pregnancy and autism-like behavior in children. The scientists said that other nutrients found in fish may even protect the fetus from the negative impact of mercury.

"This study shows no consistent association in children with mothers with mercury level that were six to ten times higher than those found in the U.S. and Europe," said Philip Davidson, one of the study authors from University of Rochester Medical Center, according to a news release. "This is a sentinel population and if it does not exist here than it probably does not exist."

The study is published in journal Epidemiology.

Previous research, also from Republic of Seychelles, has shown that eating fish during pregnancy can make a baby smarter.