Researchers say the one in seven children of U.S. mothers who were infected with Zika during pregnancy developed some kind of health problem.

Health officials released the conclusions Tuesday of the first long-term look at the children.

The study focused on the children of women in Puerto Rico and other territories. That's where most of the U.S. cases were seen when the mosquito-borne disease swept across the Americas more than two years ago.

Infection during pregnancy can lead to health problems in the child. Researchers found problems ranging from birth defects to conditions that became apparent only later.

The researchers looked at kids who were at least 1 year old. About 6 percent had birth defects. Adding in seizures and other problems linked to Zika, the percentage rose to 14.