Secondhand smoke causes fertility problems

Women who breathed in secondhand smoke as children or young adults were later more likely to have trouble getting pregnant and suffer more miscarriages than women not exposed to smoke, US researchers reported.

They said toxins in the smoke could have permanently damaged the women's bodies, causing the later problems, and said their finding support restrictions on smoking.

Luke Peppone at the University of Rochester in New York, Dr Kenneth Piazza of the Roswell Park Cancer Institute in Buffalo, New York, and colleagues studied 4,800 women treated at Roswell Park.

They were asked to give details of all pregnancies, attempts to get pregnant, and miscarriages, as well as their history of smoking and breathing secondhand smoke.

Overall, 11 percent of the women reported difficulty becoming pregnant, and about a third lost one or more babies, the researchers wrote in the journal Tobacco Control.

"Forty percent reported any prenatal pregnancy difficulty (fetal loss and/or difficulty becoming pregnant)," they said.

Women who remembered their parents smoking around them were 26 percent more likely to have had difficulty becoming pregnant and women exposed to any secondhand smoke were 39 percent more likely to have had a miscarriage, Peppone's team reported.

Four out of five of the women reported exposure to secondhand smoke during their lifetimes and half grew up in a home with smoking parents.

"These statistics are breathtaking and certainly points to yet another danger of secondhand smoke exposure," Peppone said in a statement.

Other studies have linked smoking with miscarriage, birth defects and sudden infant death syndrome, also known as cot death or crib death.

"The effects of tobacco usage and exposure on pregnancy outcomes remain a public health priority because 15 percent of mothers continue to smoke throughout pregnancy, and an estimated 43 million women in the United States are exposed to cigarette smoke from others," they said.

It is possible that secondhand smoke interferes with normal hormone action involved in fertility and pregnancy, the researchers said. It can also affect the woman's cervix, the opening in the uterus through which sperm passes to fertilize the egg.