In a recent study, researchers found that 40% of all pregnant women in Pakistan are exposed to secondhand smoke - causing approximately 17,000 stillbirths in a year.

In developing countries around the world especially in Asia, secondhand smoke causes thousands of still births every year. Exposure to secondhand smoke during pregnancy increases the risk of still birth, congenital malformations, low birth-weight and respiratory illnesses. The team from the University of York looked at the number of pregnancies alongside smoking exposure data in 30 developing countries from 2008 to 2013.

The analysis revealed that in Armenia, Indonesia, Jordan, Bangladesh and Nepal more than 50% of pregnant women reported exposure to household secondhand smoke. In Indonesia alone, 10,000 still births take place every year. In Pakistan, only 1% of still births are attributed to women actively smoking during pregnancy, but for secondhand smoke, the figure is 7%, largely due to the high numbers of pregnant women exposed to tobacco smoke in the home.

In five of the 30 countries, household secondhand smoke exposure was twice as common as active smoking. "This is the first study which provides national estimates for 30 developing countries on secondhand smoke exposure in pregnancy and it reveals a huge problem, a problem which is not being addressed," said a lead researcher Kamran Siddiqi.

"We have shown for the first time that secondhand smoke during pregnancy is far more common than active smoking in developing countries, accounting for more stillbirths than active smoking. Protecting pregnant women from secondhand smoke exposure should be a key strategy to improve maternal and child health," he added. They also say further work is needed to develop effective interventions to reduce household exposure to secondhand smoke. The study appeared in the BMJ Tobacco Control Journal.