Zika Infection During 3rd Trimester May Not Harm Fetal Development

HealthDay News — The danger of Zika-related birth defects may be confined to maternal infections that occur during the first 2 trimesters of pregnancy, according to a study led by Margaret Honein, PhD, of the US Centers for Disease Control and Prevention, and published in the New England Journal of Medicine.

Colombian and US researchers studied 11 944 pregnancies occurring in 2015 among women in Colombia, a country that is endemic for the mosquito that spreads the Zika virus.

The study detected no cases of infant abnormalities among women who contracted Zika during the last 3 months of their pregnancy, the researchers said. They stressed that at the time of the study’s publication, 10% of the 1850 women infected late in pregnancy had not yet given birth, therefore the data remain incomplete and preliminary.

Still, data on the other 90% of women suggest that “maternal infection with the Zika virus during the third trimester of pregnancy is not linked to structural abnormalities in the fetus,” the researchers concluded.


Pacheco O, Beltrán M, Nelson CA, et al. Zika Virus Disease in Colombia – Preliminary Report. N Engl J Med. 2016; doi:10.1056/NEJMoa1604037.