Myth: A women can't get pregnant during her period.

    While a woman is unlikely to conceive during menstruation, "nothing, when it comes to pregnancy, is impossible," said Aaron Carroll of Indiana University and co-author of "Don't Swallow Your Gum: Myths, Half-truths and Outright Lies About Your Body and Health" （St. Martin's Griffin, 2009）.

    Once inside a woman, sperm can wait for an egg for up to a week. Ovulation can occur soon after, or even during, the bleeding phase of a woman's menstrual cycle, giving patient sperm the chance to get lucky. The timing method of birth control doesn't work well, Carroll said, agreeing that couples who practice it are often called: parents.

    Myth: Menopause causes sex drive to nosedive.

    The Change is not necessarily one that happens in the bedroom. A comprehensive survey of sexual habits in the United States, completed by Edward Laumann and colleagues in 1994, found that roughly half of women in their fifties have sex several times a month.

    While hot flashes and other discomforts may make a women temporarily not in the mood, there is not a direct link between menopause and sexual desire, Vreeman said. So if you are entering the Big M, there is no reason to say good-bye to the Big O.

    Myth: Antibiotics make birth control pills unreliable.

    "Many physicians even believe this," Carroll said. Alone, birth control pills fail about one percent of the time. And that failure rate is unchanged when taken with the vast majority of antibiotics, Carroll said.

    A possible exception is rifampin, the antibiotic prescribed for tuberculosis. Rifampin does lower pregnancy-protecting hormone levels induced by birth control pills, but whether the effect is large enough to increase pregnancy risk is unclear. Carroll thinks rifampin research spurred the antibiotic/birth control rumor. "Sometimes people say things and they just take off," he said.

    Myth: Women and men need equal sleep.

    Tossing and turning not only causes women more psychological distress, it also raises their insulin and inflammation levels -- risk factors for compromised health, found a 2008 study of 210 people led by Edward Suarez at Duke University.

    A study of more than 6,000 participants, led by researchers at the University of Warwick in 2007, found that women who slept five or less hours a night were twice as likely to suffer from hypertension than women who slept for seven or more hours. Among men, there was no such relationship. Sleeping Beauty may be better off waking up on her own watch.

    Myth: A doctor can tell if a woman is a virgin.

    Even when using 10-fold magnification, doctors can not accurately sort virgins from the sexually-active, several studies have reported. It is not as simple as looking for a hole in the hymen because, well, there is always a hole in the hymen.

    "Some people think the hymen seals off the vagina [until virginity is lost], but that is just not true," said Dr. Rachel Vreeman of Indiana University and Carroll's co-author of "Don't Swallow Your Gum." In the rare cases when it is sealed, period blood builds in the uterus and causes severe medical problems, she said.

    誤區(qū)：女性在月經(jīng)期間不能懷孕

    雖然女性在經(jīng)期不太可能懷孕，但印第安那州大學(xué)的埃倫。卡羅說(shuō)："說(shuō)到懷孕，一切皆有可能。"同時(shí)，他也合寫過(guò)"別吞口香糖： 對(duì)你的身體和健康荒誕，半真半假的說(shuō)法甚至是十足的謊言".（圣。 馬丁格里芬出版社，2009）

    一旦精子進(jìn)入了女性的身體， 它能存活長(zhǎng)達(dá)一周的時(shí)間來(lái)與卵細(xì)胞結(jié)合。排卵可能在女性月經(jīng)周期結(jié)束后發(fā)生， 也可能在經(jīng)期內(nèi)排血的階段發(fā)生， 使得耐心等候的精子就有機(jī)會(huì)與卵細(xì)胞結(jié)合。 計(jì)算安全期的方法并不能有效地避孕，卡羅說(shuō)道。 同時(shí)他認(rèn)為那些使用這種方法來(lái)避孕的夫妻很可能會(huì)成為父母。

    誤區(qū)： 更年期是性欲的殺手

    這種改變并不一定是臥室里發(fā)生的那種改變。 1944年，由愛德華。勞曼和他的同事一起完成的關(guān)于美國(guó)人性習(xí)慣的全面的調(diào)查顯示， 五十多歲的女性中大約有一半的人一個(gè)月會(huì)有好幾次性生活。

    熱潮紅和其他方面的不適可能會(huì)使女性暫時(shí)的心情不適因而不想進(jìn)行性生活，所以更年期和性欲并沒(méi)有之間的關(guān)聯(lián)， 弗爾曼說(shuō)。 所以當(dāng)你進(jìn)入更年期，你不必和性快樂(lè)說(shuō)拜拜。

    誤區(qū)： 服用抗生素導(dǎo)致避孕藥失效

    "甚至許多醫(yī)生都相信這個(gè)說(shuō)法。" 卡羅說(shuō)。 單單吃避孕藥的話， 失敗率大約1%. 而當(dāng)你在吃避孕藥的同時(shí)， 還服用大多數(shù)種類的抗生素時(shí)， 失敗率還是1%.

    可能的例外就是利福平，這種抗生素是專為治療肺結(jié)核研制的。利福平確實(shí)會(huì)降低服用避孕藥所產(chǎn)生的適合懷孕的荷爾蒙含量， 但是這種反應(yīng)是否大到可以影響懷孕機(jī)率的程度還不知曉。 卡羅認(rèn)為利福平的研究使得人們?cè)絹?lái)越相信抗生素使避孕藥失效的謠言。 " 有時(shí)，人們講話，講完了就不管了。" 他說(shuō)

    誤區(qū)： 女性與男性需要相同時(shí)間的睡眠。

    輾轉(zhuǎn)反側(cè)不僅使女性在心里上感到不安愁悶，還會(huì)提高她們體內(nèi)的胰島素的含量以及容易發(fā)生炎癥-這些會(huì)危害健康。 這是由德克大學(xué)的愛德華。蘇瑞在2008年通過(guò)對(duì)210人進(jìn)行研究發(fā)現(xiàn)的。

    2007年，沃里克大學(xué)的研究者對(duì)6000多人進(jìn)行研究發(fā)現(xiàn)晚上睡眠為5小時(shí)或更少的女性得高血壓的可能性是比那些睡7個(gè)小時(shí)或更多的女性的兩倍。而在男性中，沒(méi)有這種比例關(guān)系。

    睡美人最好按自己的生物鐘起床。

    誤區(qū)：醫(yī)生可以分辨出你是否是處女。

    即使醫(yī)生使用十倍的放大器材，他們還是不能精確地將處女與性經(jīng)驗(yàn)豐富的女性區(qū)分開來(lái)，好幾個(gè)研究都報(bào)導(dǎo)過(guò)。這并不是簡(jiǎn)簡(jiǎn)單單地尋找處女膜上是否有洞，因?yàn)樘幣�膜上總是�?huì)有洞的。

    "有人認(rèn)為處女膜將陰道封住了（直到喪失了貞操）,但這是不對(duì)的。"印第安那州大學(xué)的博士瑞秋。弗爾曼說(shuō)。 同時(shí)他和卡羅一起合寫了 "別吞口香糖". 這樣的例子很少，當(dāng)它被封住時(shí)，經(jīng)血會(huì)涌入子宮， 而且會(huì)造成嚴(yán)重的疾病， 她說(shuō)。