If your health isn’t enough to encourage you quit smoking, then the health of your baby should be. Smoking while pregnant increases the possibility of stillbirth, miscarriage and low birth weight – especially in teens and young adults. Teens and young women have the highest reported smoking prevalence, and it’s only getting worse. The problem is kids experiment with tobacco and it often turns into a lifelong habit. Nearly 90 per cent of adults say they started smoking by the age of 18.This is a reflection of aggressive tobacco industry marketing to girls. Tobacco companies advertise in magazines, market their brands through direct mail and adverts, promote their products in convenience stores and coerce youth through Internet websites and social media sites.They fail to mention that tobacco smoke contains more than 7 000 chemicals and at least 60 cancer-causing compounds. Two compounds are especially hazardous to a mother and child: highly addictive nicotine and carbon monoxide. Pregnant women often have intensified desires for cigarettes due to increases in their metabolism. The addictive effect is very strong and often proves extra difficult to cut cravings. However, according to a new study, a brisk walk has been shown to temporarily reduce the effects of nicotine. Exercise was known to interrupt nicotine cravings for men and women, but it was still unclear for expecting young mothers. "This was the first time we have been able to replicate the findings with pregnant smokers,” said Harry Prapavessis, director of the Exercise and Health Psychology Laboratory at Western University in Ontario, who led the research.As little as 15 to 20 minutes of walking at a mild to moderate pace was found to ward off cravings. Additional benefits included less irritability, restlessness, tension and other withdrawal symptoms. There’s no safe amount of smoking for pregnant women of any age, the more you smoke, the worse the outcomes for your baby. This is not true for exercise, it’s good for you and your baby. Exercise can prevent excess weight gain during pregnancy, prevent gestational diabetes and lower the risk of birth complications. Being more fit can also help with pregnancy-related aches and pains, which makes labour and recovery a bit easier. Even if you don’t quit, regular exercise is still beneficial to you and your child. When you exercise, your lungs and blood vessels expand which increases circulation of oxygenated blood throughout you and your baby’s body.Regular exercise during pregnancy has been proven to reduce stress, improve sleep and prevent depression as well. Just don’t exercise too close to bedtime, or you may be too energized to fall asleep and experience insomnia.Barring certain pregnancy related risk factors, pregnant women can continue to exercise throughout their pregnancy, right up until delivery. Isometric, or contract and relax exercises are recommended for expecting moms to improve core strength and support pelvic ligament laxity, particularly during late pregnancy.Remember to check with your doctor before starting a new exercise programme, especially if you have any health concerns.Dr Cory Couillard is an international health columnist that works in collaboration with the World Health Organization’s goals of disease prevention and control.