Estimates suggested there has been at least a doubling in requests in Brazil and an increase of a third in other countries, BBC reported on Thursday.
Many governments have advised women not to get pregnant due to the risk of babies being born with tiny brains in a condition known as microcephaly.
The researchers analysed the thousands of requests received by Women on Web — advises women online and then delivers pills to end a pregnancy — in the five years before the Pan American Health Organisation issued its warning on Zika on November 17, 2015.
It used this to predict how many abortion requests would have been expected between November 17, 2015 and March 1, 2016.
The analysis of countries that advised against getting pregnant suggested Brazil and Ecuador had had more than twice the expected demand for abortions.
However, a termination remains illegal in many parts of Latin America, but women simply turn to unofficial providers.
Analysis from other countries, which did not advise against pregnancy, suggested smaller increases in abortion demand.
The findings were published in the New England Journal of Medicine.