Researchers at University of Rochester Medical Center have discovered more life-altering reasons for women to avoid second-hand smoke: it may lead to fertility problems or miscarriages.

An analysis of more than 4,800 non-smoking women in the U.S. showed that women who were exposed to six or more hours per day of second-hand smoke during childhood and as adults had significantly more difficulty conceiving or suffering miscarriages. In fact, researchers found that their chances for both increased by 68 per cent due if they had been exposed to second-hand smoke over a long period of time.

"The numbers are astonishing. They show another danger of second-hand smoke exposure," Dr. Luke J. Peppone, the researcher who conducted the study, told CTV.ca by phone on Friday.

The study of 4,804 women found that:

  • Four out of five women reported exposure to second-hand smoke during their lifetime.
  • Half of the women grew up in a home with smoking parents.
  • Nearly two-thirds of them were exposed to some second-hand smoke at the time of the survey.
  • More than 40 percent of these women had infertility lasting more than a year or suffered miscarriages, some repeatedly.

"Individuals need to be responsible," Peppone said, noting the new study is alarming because it shows the long-term effects of second hand smoke.

He said researchers can't prove second hand smoke caused the health problems, but there is a correlation. He said parents who smoke need to understand that their habit could irreparably harm their kids' health -- and leave them without grandchildren.

"When people are smoking they should not expose young women with their smoke ... It has lasting effects, especially for women when they're ready for children," he said.

Peppone said he agrees with measures taken by some Canadian provinces to ban smoking in cars when children are present.

"We can't go back and change what happened in the past. We need to know this, and respond accordingly from now," he said.

Peppone's findings were based on a 16-page survey conducted between 1982 and 1998. The surveys focused on women's lifestyle, habits, family and personal health history, and occupational and environmental exposures. The participants, all of whom had become pregnant or tried to become pregnant at some point in their lives, were non-smokers.

The study is published online in Tobacco Control.