Researches showed that kids with at least one smoking parent had 5.5 times higher levels of cotinine in their urine. Cotinine is a break-down product of nicotine from cigarette smoke and is a valuable indicator of tobacco smoke exposure as its levels in the blood are proportionate to the amount of exposure to tobacco smoke.

A study done by Warwick Medical School and the University of Leicester showed that having a smoking mother had the biggest independent effect on cotinine levels in the urine.

Around 100 infants aged 12 weeks had their urine samples taken and cotinine levels measured. Seventy one of the newborns had parents who smoked. The measurements showed that a smoking father doubles the amount of cotinine in the child’s blood and that children who shared rooms or slept with their smoking parents had higher levels due to greater exposure to the contaminated cloth.

These study results clearly indicate that babies are being severely damaged in physiological terms by their parents smoking and that they are quickly becoming passive smokers. Parental smoking was also found to be one of the leading causes of sudden infant death syndrome. It is thought that children could be inhaling smoke-contaminated particles from cloths and other objects.

The levels of cotinine found in children with smoking parents were so high that it looked as if children were smokers themselves.
It is now believed that newborns of mothers who smoke are at five times higher risk of dying from cot death.