"Preliminary surveillance data in Colombia suggest that maternal infection with the Zika virus during the third trimester of pregnancy is not linked to structural abnormalities in the fetus," the article stated on Wednesday. "However, the monitoring of the effect of ZVD [Zika Viral Disease] on pregnant women in Colombia is ongoing."
The structural abnormality of Zika babies consists primarily of undersize heads associated with a condition known as microcephaly. Many other neurological abnormalities that are not immediately observable are also associated with babies born to infected mothers, according to medical experts.
Since the monitoring did not begin until August 2015 and the data is from babies born before April 2, many of the women had not yet given birth, the article explained.
Separately, US Centers for Disease Control Director Tom Frieden warned in a tweet that cases of microcephaly are starting to emerge in Colombia, including four instances of babies born in late April whose mothers did not report any symptoms of Zika.