Fever During Pregnancy Tied to Autism in Study

Children whose moms have any type of fever during pregnancy may have slightly increased odds of developing an autism spectrum disorder, a new study suggests.

The large study found that one episode of fever in the second trimester might increase the risk for autism by 40 percent. Several bouts of fever after the twelfth week of pregnancy could raise the risk threefold, researchers reported.

"Fever is a response to a wide range of infections, and it is common during pregnancy," said lead researcher Dr. Mady Hornig. She's an associate professor of epidemiology at Columbia University's Mailman School of Public Health in New York City.

But she pointed out, "The absolute risk is low. The vast majority of women who get an infection with fever, even flu, are not going to end up having a child with autism."

Hornig also cautioned this study cannot prove that a fever during pregnancy causes autism, only that there appears to be an association.

The researchers also cannot tell what it is about fever that might have this effect. Hornig speculated that it might involve the body's reaction to a fever-causing infection that also has an effect on fetal brain development.

Zika Risk May Be Lower Than Thought for Some Pregnant Women
U.S. study found only 1 of 185 who traveled to active areas tested positive, and baby wasn't infected

U.S. women traveling to areas where the Zika virus is circulating might be less likely to be infected than expected, but risk remains, a new study suggests.

Only one out of 185 pregnant women at a Los Angeles clinic who visited an active Zika area between January and August 2016 wound up infected, researchers report.

"Overall, for women who have had exposures to Zika virus, the risk of maternal infection is low," said lead researcher Dr. Rashmi Rao, an obstetrician and gynecologist with the University of California, Los Angeles Medical Center.

But, the risk of Zika infection "isn't zero, and I want to make that very clear," Rao continued. "Our party line for women remains that we don't recommend they travel to these areas at all, particularly if they are considering pregnancy or are pregnant."

The one woman who contracted Zika developed her infection during a 12-day stay in Honduras, during the early first trimester of her pregnancy, the researchers reported. She tested positive for the virus and did report mosquito bites, but said she hadn't had any symptoms related to Zika infection.

Doctors closely monitored the child she was carrying, but both the child and her amniotic fluid tested negative for Zika. A healthy delivery followed, and at 3 months old the baby shows no sign of Zika-related birth defects.

Rao and her colleagues decided to conduct their investigation to see how much risk pregnant women faced in traveling to Zika-active areas.

Zika has been linked to a number of devastating birth defects, most of them brain-related. The most widely known is microcephaly, in which babies are born with underdeveloped skulls and brains.

During the first eight months of 2016, the UCLA maternity clinic in this study evaluated 185 pregnant women with potential exposure to Zika, the researchers said.

About 17 percent of the women had been exposed to Zika during travel to the active transmission area that occurred in Miami-Dade County in Florida during the summer of 2016, the researchers found.