Based on the reported data from Brazil in 2015/16, this publication describes a plausible range for the risk of microcephaly in women who were infected with Zika virus during pregnancy compared to those who were not infected. The key message is that the large uncertainty around the risk estimate needs to be further investigated because of a) the possible existence of co-factors that are yet to be validated, b) the assumptions that need be made for the proportion of women who were infected during pregnancy.

10th March 2017 • comment