As many as 1.65 million women in Latin America could be infected with Zika while pregnant, meaning tens of thousands of pregnancies could be at risk, researchers said Monday.
It's the first real estimate of just how many actual pregnancies are at real risk, based on birth rates in each country and other factors, NBC News reported.
Brazil's likely to be the worst affected, the team at the University of Notre Dame and Britain's University of Southampton found.
Their best estimate is between 1.5 million and 2 million women will get infected while pregnant during the first wave of the Zika epidemic if it lasts two to three years. They settled on 1.65 million as the most likely number.
Zika's known to cause a range of birth defects, from brain damage that leads to an unusually small head, called microcephaly, to more subtle nerve, organ and limb defects.