Doctors hope a new monitoring system will give clearer figures on the impact of the Zika virus on New Zealand children.
From next month all babies under six months with microcephaly, or other brain abnormalities, and whose parent has been in a country with the active virus just prior to or after its conception are to be reported.
The New Zealand Paediatric Surveillance Unit, which will receive the reports, will monitor the cases and establish just how many, if any, were directly related to Zika.
Unit epidemiologist, Nigel Dickson, said the monitoring will give medical professionals a clearer idea of how best to respond to the virus.