Women who have ever been around smokers regularly may have more difficulty getting pregnant than those who have not, a new study suggests. The findings, researchers say, offer one more reason for women to kick the smoking habit.
Studies have found that women who smoke raise their risk of a number of pregnancy complications, as well as their infants' risk of health problems. Less is known about the dangers of secondhand smoke, though some studies have linked exposure during pregnancy to an elevated risk of miscarriage.

    In the new study, of more than 4,800 women, researchers found those who'd grown up with a parent who smoked were more likely to report they'd had difficulty becoming pregnant — defined as having to try for more than 1 year.

    In addition, women who'd been exposed to secondhand smoke in both childhood and adulthood were 39 percent more likely to have suffered a miscarriage or stillbirth, and 68 percent more likely to have had problems getting pregnant.

    "These statistics are breathtaking and certainly (point) to yet another danger of secondhand smoke exposure," said lead researcher Luke J. Peppone at the University of Rochester, New York.

    "We all know that cigarettes and secondhand smoke are dangerous," he added. "Breathing the smoke has lasting effects, especially for women when they're ready for children."

    Peppone and his colleagues at the University of Rochester in New York report their findings in the December 5 online issue of the journal Tobacco Control.

    For the study, the researchers analyzed surveys from 4,804 women who'd visited the university's Roswell Park Cancer Institute between 1982 and 1998 for health screening or cancer treatment. All had been pregnant at least once in their lives.

    Overall, Peppone's team found 11 percent of the women had difficulty becoming pregnant, while one third had a miscarriage or stillbirth.

    The risk of these problems tended to climb in tandem with the number of hours per day that a woman was exposed to secondhand smoke — a pattern that suggests a cause-effect relationship.

    Secondhand smoke contains a host of toxic compounds that could potentially harm a woman's reproductive health, Peppone and his colleagues note. Tobacco toxins may damage cells' genetic material, interfere with conception, raise the risk of miscarriage, or inhibit the hormones needed for conception and a successful pregnancy.

    一項新的研究顯示,經常被動吸煙的女性比正常女性更難受孕。研究人員稱,這項研究結果將有助于女性戒掉吸煙惡習。

    研究發現,孕婦吸煙會增加患孕期并發癥的可能性,由此孩子的健康也會受損。對于孕婦吸二手煙的危害性還有待進一步研究,但有些研究顯示,孕期被動吸煙會增加流產的可能性。

    一項由4,800多人參與的研究表明,有吸煙史人的子女更有可能經過1年以上的嘗試也不易懷孕。

    此外,從兒時到成年時期都吸二手煙的女性有39%在懷孕期間更容易導致流產或死胎,68%的人很難受孕。

    研究小組組長,紐約羅徹斯特大學的盧克.杰.派鵬介紹說,“這些數據觸目驚心,證明了二手煙帶來的又一風險。”

    “我們都知道吸煙和被動吸煙有害健康,吸入的煙會產生一個長期的影響,尤其對于那些準備懷孕的女性影響更多。”

    12月5日,派鵬和他的研究小組在《煙草控制雜志》上刊登了研究報告。

    研究人員對4,804位于1982年至1998年期間到Roswell Park腫瘤醫院進行身體檢查或接受治療的女性患者情況進行了分析,這些女性都至少有過一次懷孕的經歷。

    派鵬小組研究發現,其中11%的女性難以受孕,三分之一的女性有過流產或死胎的經歷。

    女性被動吸二手煙,上述問題發生的危險性與時俱增—這已經形成了一種原因-結果的關系模式。

    派鵬和他的研究小組指出,二手煙包含一系列有毒成份,可能會潛在地損傷女性生殖健康。煙草毒素會破壞細胞遺傳物質,影響受孕,增加流產的風險性,以及阻止成功受孕所需荷爾蒙的分泌。