New research released today takes a look at birth outcomes and maternal（母亲的） smoking, building urgency for more states and cities to join the nationwide smoke-free trend that has accelerated in recent years. According to the new data, strong smoke-free policies can improve fetal（胎儿的） outcomes by significantly reducing the prevalence of maternal smoking. The study, which was presented today at the American Public Health Association's 138th Annual Meeting & Exposition in Denver, compared maternal smoking prevalence in one Colorado city where a smoking ban has already been implemented（实施，执行） to that of a neighboring city where there is no ordinance（条例，法令） .

Researchers from the University of Colorado School of Pharmacy collected data from mothers residing in Pueblo, Colo., before and after a citywide smoking ban took effect. Results show a 23 percent decrease in the odds of preterm births and a 37 percent decrease in the odds of maternal smoking in Pueblo following the ban. Birth outcomes in El Paso County, Colo., however, showed no such drop during the same time period. Findings in this first-ever study in United States reflect similar findings as national data from Dublin, Ireland.

The study suggests that smoking bans have a significant and immediate positive impact on the health of infants and mothers. Pre-term babies stand a greater likelihood of experiencing cardiovascular（心血管的） issues later in life.

"This research proves that smoking is an irrefutable（不可反驳的） risk factor for expectant mothers（孕妇） who are acutely more affected," said Associate Professor Dr. Robert Page at the University of Colorado, Schools of Pharmacy and Medicine, and lead researcher on the study, who presented the findings. "The good news is that implementing strong tobacco control policy can protect even the most vulnerable from the deadly consequences of smoking."