"Because alcohol in the bloodstream passes easily through the placenta, the baby is exposed to the same blood alcohol level as the mother."
Penaflor said September was a reminder everyone had a role to play in helping pregnant women to be alcohol free, and in looking after the health of the baby.
It is estimated one in five New Zealand women drinks alcohol at some time during their pregnancy, with this rate higher for women aged 15 to 24.
"We take the opportunity to kōrero and educate family and friends about the importance of abstaining from alcohol during pregnancy," Penaflor said.
"Some ways to be alcohol free during pregnancy include asking partners, whānau and friends to support you through pregnancy by discouraging alcohol at home and at events and having non-alcoholic drinks at social gatherings.
"By raising awareness about what causes FASD and the tragic consequences it can have on people's lives, we hope to encourage mothers not to drink while pregnant or when trying to get pregnant.
"This means more babies are born healthy, with the best chance at reaching their full potential in life."
The Alcohol Drug Helpline can be reached on 0800 787 797.