A new study is showing the ban's benefits, it has reduced the risk of premature births.
Researchers said the findings could have significant public health implications because pre-term birth has been linked to health issues early on and later in life.
In the study published in a British medical journal, Belgian researchers examined more than 600,000 thousand births. They found three successive drops in babies' births before 37 weeks - each occurring after a phase of a public smoking ban was introduced.
It is already well-established that smoking leads to reduced birth weight and an increased risk of premature birth.
