He said the cost estimate was conservative as it did not take into account the social harm - or cost to the justice, health and education systems.
Hawkes Bay District Health Board clinical psychologist Andi Crawford is the other guest speaker and will outline what work she and her colleagues have been doing to get a headstart on the problem.
Forum organiser Christine Rogan, of the Fetal Alcohol Network of NZ, said it was time DHBs got enough funding to assess, diagnose and treat the children who were falling through the cracks.
Hawkes Bay DHB was the only district health board assessing and diagnosing children with FASD.
"We're counting with vulnerable children's lives here, and we've got to stop and start doing something ... " Ms Crawford said.
"My wish is that we stop talking about babies from the day they're born and start talking about babies from the day they're conceived."