The College of Midwives says care facilities for new mothers with mental health problems are woefully inadequate.
A Perinatal and Maternal Mortality Review Committee report says suicide is the leading cause of death for pregnant woman and new mothers.
Thirteen pregnant women or new mothers killed themselves between 2006 and 2010.
There is only one mental health unit that caters for women and their babies - in Christchurch - and the report recommends setting up another unit in the North Island.
The College of Midwives says one extra mental health unit should be just the start.
The Ministry of Health hopes better services will be operating within a year.