Historically research has focused on men. As one example, women are under-represented in major clinical trials for cancers that affect both sexes, a new study found. Researchers say several factors could be responsible, from childcare issues to reluctance by researchers to expose women of childbearing age to trial drugs and treatments.

    In other areas where research into women's medical problems is lacking, the issue is not just about sexism. Women's hormone fluctuations are, well, complicated and can confound basic findings. But in recent years, women have been getting increased attention.

    Still, much misinformation about the female body circulates in mainstream consciousness.

    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.

    一直以来，大多数研究都把目光放在男性身上。比方说，在那些男人和女人都会得的癌症研究中，对于女性被试者比男性少很多。研究人员认为这是由多种因素造成的，比如由于妇女需要养育子女，因此很多研究者对让育龄妇女参加临床试验而有所顾虑。

    另一些严重对女性健康问题研究的匮乏，就不单单是因为性别歧视了。女性的荷尔蒙作用，比男性更复杂，而且会和基本研究问题产生相互作用。不过近些年，女性正在获得越来越多的关注。

    不过在我们的视野中，还有很多关于女性健康的错误观点在不断流传。

    误区：女性在来月经时不会怀孕

    虽然女性来月经时的确不容易受孕，"不过在怀孕的问题上，没有什么是不可能的。"印第安纳州大学的Aaron Carroll曾经这么说过。她曾与人合写了《别咽口香糖：关于身体和健康真真假假那些事》

    精子可以在女性体内存活长达一周。而排卵可以发生在月经周期刚结束、甚至还在流血的日子里，这让那些耐心的精子获得了机会。安全期避孕法并不可靠，Carroll说。她还给那些用这种方法避孕的夫妻们起了个名字：父母。

    误区：更年期让"性趣指数"暴跌

    这个变化不一定会发生在卧室里。1994年，Edward Laumann和同事们在美国进行的一项关于性习惯的详尽调查，调查显示，在五十多岁的女性中，大约一半每个月仍然会做几次爱。

    虽然燥热和其他的不适症状会让女人们暂时"不在状态",不过更年期和"性趣"之间没有直接联系，Vreeman说。所以，如果你到了这个时候，可不意味这你就要想"飘然欲仙"说byebye.

    误区：抗生素会让避孕药失效

    "甚至很多家庭医生都相信有这么回事"Carroll说。如果只用避孕药，失败率是1%,这个比例不会随着服用绝大部分的抗生素而有所变化。

    一种可能的例外是利福平，一种治疗肺结核的抗生素。利福平的确会让由于避孕药而产生的避免怀孕荷尔蒙水平降低，不过这个效果能否增加怀孕的危险并不清楚。Carroll认为正是对利福平的研究导致了关于抗生素和避孕药之间的流言，"有时候人们会说些自己都不清楚的事情".

    误区：女人和男人需要等量的睡眠。

    根据杜克大学Edward Suarez2008年对210人进行的调查，辗转反侧不但会造成女人心理上的压力，还会提高胰岛素水平和炎症症状，从而危害健康。

    而在另一项2007年Warwick大学研究人员对超多6000人进行的研究，那些睡眠少于每晚5小时的女性比睡超过7小时的女性，罹患高血压的几率高一倍。而在男性中却没有这种关系。睡美人最好是自然醒。

    误区：医生能分辨处女

    不少研究证明，即使用10倍的放大镜，医生也不能准确地区分处女和非处女。这并不是看处女膜有没有洞那么简单，实际上，处女膜就是有个洞。

    "有些人认为处女膜封上了阴道（直到失去贞操）,不过并不是那样。"《别咽口香糖》的另一位作者，印第安纳大学的Rachel Vreeman介绍说，在极少个案中，它的确是全封闭的，导致经血在子宫中淤积，这会导致严重的疾病。