1 in 10 pregnant women with Zika in U.S. had babies with birth defects

About 1 in 10 pregnant women with confirmed Zika infections in the U.S. last year gave birth to a baby or had a fetus with Zika-related defects, the Centers for Disease Control and Prevention announced Tuesday.

The report gives the most complete picture so far of the harm Zika has caused in the U.S., mostly after pregnant women traveled to other nations and territories where the mosquito-borne virus is much more common.

The problems included undersized heads and brain damage (microcephaly), but also seizures, difficulties with vision, hearing and movement, and developmental delays, such as trouble sitting up and eating, said CDC acting director Anne Schuchat.

“The consequences of this outbreak are heartbreaking,” Schuchat told reporters.

The new information, all from 2016:

• About 1,300 pregnant women in 44 states showed evidence of possible Zika infection.

• About 1,000 of those women completed or lost those pregnancies by the end of the year, and more than 50 of those women had a baby or fetus with birth defects.

• About 250 women confirmed Zika infections by blood tests, and 24 of them, about 10%, had affected babies. The birth defect rate was even higher, 15%, in those with infections confirmed in the first trimester of pregnancy.

“This is alarming information from my perspective,” said Jeffrey Duchin, the chief public health officer for Seattle and King County and a spokesperson for the Infectious Diseases Society of America. “Zika continues to present a terrible threat to pregnant women and infants, and we need to improve awareness among pregnant women and their providers.”

Right now, CDC reports no active transmission of Zika in the continental United States, though some cases were spread by mosquitoes in South Florida and Texas in 2016. More widespread transmission has been reported in South America, Central America and the Caribbean, including Puerto Rico, which is not included in the new report.

Pregnant women should not travel to areas where Zika is spreading, CDC says. And every pregnant woman should be asked about her travel history and that of her partner, since Zika can sometimes spread sexually, Duchin said.

It’s also important for women who might have been infected to have their babies watched closely after birth, since not all related birth defects are immediately obvious, CDC officials said.

The agency recommends brain scans for possibly affected infants, but only a quarter of such babies received those tests in 2016, the new report said.