by Michael J. Shapiro | February 18, 2016

A new study published in the journal Lancet Infectious Diseases lends more support to a link between the Zika virus and microcephaly, the condition in which babies are born with abnormally small heads. The case report was based on two pregnant women in northeastern Brazil who had shown symptoms of the Zika virus, and for whom ultrasounds indicated microcephaly in their fetuses. Scientists were able to confirm the presence of the Zika virus in the amniotic fluid, supporting the theory that the virus could be passed from mother to fetus during pregnancy.

The study, however, does not prove that Zika caused the microcephaly. "We have only a few microcephaly cases where we confirmed the presence of the virus in babies," said Dr. Ana de Filippis, the Rio de Janeiro-based lead scientist in the study. "We need more data to make sure that only Zika is responsible in these microcephaly cases... But I think that these findings in the amniotic fluids are pointing in the direction that Zika has an important role."

However, added de Filippis, many other potential factors could affect the ability of the virus to pass through the placenta -- even the potential presence of other virus antibodies. What's more, while confirmed Zika cases among pregnant women are growing throughout South and Central America, the microcephaly cases still are mainly being found in the northeast of Brazil. "It's very important that some genetic studies be conducted in these pregnant women in this population, to see if there is some marker that would explain why we are seeing so many cases in these areas," said de Filippis.