日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

  Home>News Center>Life
         
 

Sex more likely when women are most fertile
(Agencies)
Updated: 2004-06-10 07:53

Women are likely to have more sex on the days when they are most fertile, even if they are not trying to get pregnant, scientists said on Thursday.

That means that taking a chance and having sex without using contraception could be more likely to result in unwanted pregnancies than previously thought.

"There apparently are biological factors promoting intercourse during a woman's six fertile days, whether she wants a baby or not," said Professor Allen Wilcox, of the National Institute of Environmental Health Sciences in Durham, North Carolina.

But he and his colleagues do not understand the reasons and doubt that women are even aware of them.

In a study of 68 women who recorded when they had sex over a three-month period, Wilcox and his colleagues discovered that during ovulation, when a woman is most likely to become pregnant, the overall frequency of sex increased by 24 percent.

"There are some biological mechanisms at work here that curiously we know very little about," he said in an interview.

"It suggests that couples who 'take a chance' with unprotected intercourse have the deck stacked against them. Intercourse does not happen randomly," Wilcox, who reported the findings in the journal Human Reproduction, added.

He and his colleagues are not sure why sex is more frequent during a woman's most fertile time of the month, but they suspect there are a few factors at work.

Most women have about six fertile days a month -- the five days preceding ovulation and the day of ovulation.

A woman's libido may be heightened when she is ovulating so she has an increased interest in sex, or she may produce more pheromones, chemicals that send messages to other individuals, that increase her sexual attractiveness.

Animal studies have also shown that having sex accelerates ovulation.

"For couples who want a baby these biological mechanisms are a silent partner, helping to optimize the timing of intercourse," Wilcox said.

But he said women who do not want to conceive should be aware that unprotected sex may be riskier than the odds suggest.

"For couples who don't want to conceive the message would be that when you take a chance that chance is even bigger than you might think."

 
  Today's Top News     Top Life News
 

State bank splits up in pilot reform

 

   
 

Beijingers rally around Olympic relay

 

   
 

Hu signs communique in Warsaw

 

   
 

Officials sacked over fake milk fiasco

 

   
 

Beijing building fire kills 9, injures 39

 

   
 

DaimlerChrysler to invest 1b euros in China

 

   
  Quarrels do more harms to children than divorce
   
  Rover finds more signs of water on Mars
   
  Newlywed J-Lo expecting baby: report
   
  Shanghai indie goes mainstream
   
  Musicians sink roots in reality
   
  Prince Charles to marry again? Who cares
   
 
  Go to Another Section  
 
 
  Story Tools  
   
  Feature  
  Eminem exposing rear to be edited  
Advertisement
         
主站蜘蛛池模板: 欧美一区二区精品 | 久久草视频在线 | 天天干,天天干 | 婷婷色网| 中出av在线 | 不卡的毛片 | 亚洲国内精品 | 河智苑色即是空 | 欧美日韩午夜视频 | 成人一级片在线观看 | 欧美 日韩 综合 | 国产97在线观看 | 日韩欧美一卡 | 国产男人的天堂 | 天堂√8在线中文 | 午夜在线免费观看视频 | 中文字幕永久在线视频 | 韩国精品一区二区三区 | 天堂中文av | 黄色一级一级 | 成人免费视频网址 | 欧美一区二区三区爽爽爽 | 一道本视频在线 | 亚洲成人18 | 免费av高清 | 欧美三级视频在线 | 全部免费毛片在线播放高潮 | 中文字幕永久在线视频 | 日本午夜在线 | 久久精品成人一区二区三区蜜臀 | 日本成人一区二区 | 自拍视频在线观看 | 午夜精品区 | 亚洲色图日本 | 三级视频在线看 | 色综合视频在线 | 成人黄性视频 | 免费黄色在线网址 | 成年人视频网 | 奇米影视亚洲春色 | av大全在线 |