A commentary details that while Zika virus is an unlikely threat in much of Europe, the challenges for surveillance of birth defects should be addressed to strengthen the quality and effectiveness of this essential public health function. While birth defects registries perform a vital population health function, registers of pregnancies affected by Zika virus with longitudinal follow-up of both mother and child must be established urgently to fully understand the natural course of the Zika syndrome and its impact on child growth and development.