The Waikato District Health Board (DHB) has found that half of all pregnant Maori women in the rohe are smokers.
Dr Nina Scott, of the DHB's Maori Health Service Te Puna Oranga, said about 200 of the 400 women smoked while hapu, and her department wanted to reduce those numbers.
The department was using several ways to do that, including teaching mothers about the risks of smoking to babies and offering them gift voucher incentives, she said.
Dr Scott said it was also working towards training nearly all of the professionals who worked with expectant mothers in smoking cessation, which would help improve data about pregnant smokers.
She said staff enjoyed the training, which was run by midwives.
The DHB found the rate of female smokers earlier this year sat at about about 38 percent, Dr Scott said.
But she said that after training midwives, that percentage increased to more than 50 percent, which she was certain was because midwives were questioning expectant mothers about their smoking habits.