Risk of Zika-caused microcephaly highest among women infected early in pregnancy: study

Women infected with the Zika virus early in their pregnancies are at the highest risk of giving birth to infants with abnormally small heads, a condition known as microcephaly, a report released Friday said.

The report, published by the U.S. Centers for Disease Control and Prevention's (CDC) Morbidity and Mortality Weekly Report, said that Colombia reported 476 cases of microcephaly from January 31 through mid-November, more than a four-fold increase from the same period in 2015.

Of these cases, 432 were live-born infants and 44 were pregnancy losses.

The peak month for reported cases of microcephaly occurred in July, which came about six months after the peak of the Zika outbreak in the South American country, it said.

For that month, there were 94 reported microcephaly cases, about nine times the number in the same month in 2015.

The finding "suggests that the greatest risk for microcephaly is associated with Zika virus infection during the first trimester and early in the second trimester of pregnancy," the report wrote.

The U.S. CDC, however, recommended that women take steps to protect themselves during the entire pregnancy.

Overall, Colombia reported about 105,000 cases of Zika virus disease, including nearly 20,000 cases in pregnant women, from August 9, 2015, through November 26, 2016.

"This preliminary report on Zika virus disease and microcephaly in Colombia demonstrates that an increase in microcephaly is not specific to Brazil," the U.S. CDC said in a statement.

"This finding confirms that countries with Zika virus outbreaks are likely to experience large increases in microcephaly and other Zika-related birth defects." Enditem