ON OVULATION, PERIOD, INFERTILITY, SEX, ORGASM, PREGNANCY, PMS, MENOPAUSE, ETC.
Window of opportunity only six days – All pregnancies resulted from sex on day of ovulation or one of the 5 days before.
By Kim Painter – USA Today
The facts of life may not be quite what you think. Scientists dispel some of the more enduring myths about human conception with a new study that pinpoints the long. sought window of fertility - the time during a woman's monthly cycle when she can become pregnant. That Window consists of six days: the day of ovulation and the five days leading up to it, the study says. Just one day after ovulation, the window appears to be firmly closed, at least for most women, says the report in Thursday's New England Journal of Medicine.
In fact, "the more Inter- course you have, the greater chance you have of getting pregnant, " Wilcox says. ~ Contrary to claims made In several popular books, the timing of sex had no effect on gender.
But he says sex on the day of ovulation or the two days before produced the vast majority of pregnancies in his study as well.
---------------------------------------------------------
A New Rhythm Method to Get Pregnant
Study finds earlier, shorter period for fertilization
By Curt Suplee
WASHINGTON -Couples who are trying to get pregnant, or trying not to, may need to change the rhythm of their method, according to a new study. Researchers reported in Thursday's The New England Journal of Medicine that the highest probability of pregnancy each month occurs during a 4 six-day period ending on the, day of ovulation, a time frame.
The researchers found that all pregnancies in the study group were initiated on the day of ovulation or during the five previous days; none was produced by intercourse after this interval.
~~~
Men Sense 'Scent of a Woman'
NEW YORK (Reuters Health) - Could love truly be in the air? Researchers in Texas believe men become especially attuned—andattracted to--female body odors during the most fertile stage of the menstrual cycle.
``These findings raise serious doubts about conventional scientific wisdom that human female ovulation is concealed...and that men cannot detect when women are ovulating,'' according to Drs. Devendra Singh and P. Matthew Bronstad, psychologist researchers at the University of Texas in Austin.
“These findings suggest that ovulation may not be concealed and that men could use ovulation-linked odors in their mate selection,'' Singh and Bronstad conclude.”
~~~
Age, Confidence Big Factors in Achieving Orgasm
NEW YORK (Reuters Health) - Factors such as age, confidence in one's sexual prowess and preference for either ``fast'' or ''slow'' sex help determine how often men and women achieve orgasm, according to a new survey of more than 2,200 adults in Finland.
Overall, individuals ``who have developed a perception that they are skilled and experienced lovers are more orgasmically responsive''
~~~
"In one ounce of semen there's a concentration of the most valuable chemicals distilled from 60 ounces of blood".
~~~
Big teen secret: most are not having sex
NEW YORK, Mar 01 (Reuters Health) -- While 3 out of 4 American teens assume that most of their peers are having sex, only 40% of teens say that they've actually had sexual intercourse, according to a national survey released this week by Seventeen Magazine.
However, the majority of teens are indeed sexually active. Fifty-five percent of teens say they have had oral sex, although 40% do not define oral sex alone as being ``sex.'' Over half said they thought that oral sex was ``gross.''
~~~
Virginity
Worldwide, the average age that men lose their virginity is 15, and for women, 16, according to an international survey of 16 to 21 year olds. The survey, which included 4,900 sexually and non-sexually active individuals from 14 countries -- also showed that young people have sex about 98 times a year, and about half expect to have sex within the first month of meeting a new partner. ``Kids are having sex much younger'' than in previous years but ``they are using condoms. They're protecting themselves in ways other generations haven't,''. Not all of the 16 to 21 year olds were sexually active. The most popular reason for remaining a virgin was because they were not ready for sex (47%) or they ``have not met the right person'' (27%). ``I think what we owe to the next generation is good information and good family connections, where the family can take charge and be able to educate their kids about sex and sexuality,''
~~~
Noting that 87% of the girls with STDs had no symptoms when they came to the clinic, Bunnell and her team emphasize that ''frequent screening for STDs is critical for sexually active adolescents,'' and recommend screening for chlamydia every 6 months.
~~~
Low-fat vegetarian diet may reduce PMS symptoms NEW YORK, Feb 04 (Reuters Health) -- Consuming a low-fat, vegetarian diet appears to reduce the length and severity of menstrual cramps and other premenstrual symptoms, US researchers suggest.
According to the study in the February issue of the journal Obstetrics & Gynecology, menstrual cramps are caused by prostaglandins, substances that come from traces of fat stored in cell membranes in the uterus. Sex hormones such as estrogen drive production of prostaglandins.
~~~
Sexual Decline in Women Due to Aging, Menopause
By Melissa Schorr
NEW YORK (Reuters Health) - Women experience a decline in sexual responsiveness later in life as a result of both aging and menopause, Australian researchers report.
And, the study's authors suggest, other aspects of sexuality probably also decline as a direct result of menopause.
~~~
US Is World's Sexual Superpower
By Rodney Joyce
The United States remains the sexual superpower of the world with Americans making love more often and with more partners than any other nationality, according to a survey by a leading condom manufacturer.
Durex said on Tuesday that its annual poll of 18,500 people in 28 countries showed the world was having more sex and starting earlier than ever before, and the United States was leading the field in all departments.
~~~
Morning-After Pill Found to Work 5 Days After Sex
By Melissa Schorr
A new study by Canadian researchers questions the conventional wisdom that women who have had unprotected sex must use emergency contraception within 72 hours to prevent an unwanted pregnancy.
The investigators found that taking so-called ''morning-after'' pills 3 to 5 days after having unprotected sex was up to 87% effective in preventing pregnancy, while receiving the treatment within 3 days, as has been recommended for decades, was up to 90% effective.
[within 5 days doctor can install a sterile IUD inside the womb]
~~~
Less Time With Partner, More Interest in Sex
NEW YORK (Reuters Health). According to researchers, the less time a man spends with his female partner after having sex, the more attractive he finds her--and the greater his interest in having sex with her again. This phenomenon may arise from an evolutionary strategy known as ''sperm competition,'' according to Todd K. Shackelford, an assistant professor of psychology in the College of Liberal Arts at Florida Atlantic University.
``The bottom line here is that we find (this) effect for men but not for women,'' he said. Shackelford and his colleagues presented the findings at the 107th Annual Convention of the American Psychological Association, held earlier this month in Miami.
~~~
Thursday January 11 1:33 PM ET Women's Mental Skills Vary During Monthly Cycle
NEW YORK (Reuters Health) - Hormones may help explain some of the differences in the ways that men and women think, according to a report.
As a rule, women outperform men on tests of verbal skills, while men tend to score better on tests measuring spatial abilities, which include such skills as rotating an object mentally. Some research suggests that the differences may be explained in part by varying levels of hormones in men and women.
``We conclude that spatial performance is sensitive to hormonal fluctuations over the menstrual cycle and that different aspects of spatial abilities are related to different hormones or hormone combinations,'' the authors write.
~~~
High Ozone Levels Hurt Sperm Count, Study Finds
Ozone can adversely affect a man's sperm, reducing their numbers as well as theircrucial ability to move or "swim," according to new research that evaluated more than 14,000 sperm samples.
"Our most significant finding was that as the ozone level went up, the sperm concentration went down," said Dr. Rebecca Z. Sokol, a professor of medicine and obstetrics and gynecology at the University of Southern California's Keck School of Medicine. Sokol presented her findings here Friday at a meeting of the Pacific Coast Reproductive Society.
~~~
Biological Clock Starts Ticking in Late 20s: Study
LONDON (Reuters) - A woman's biological clock starts ticking in her late 20s, not her mid-30s, and male fertility also begins to wane with age, doctors said Tuesday.
In what is thought to be the first study to show a drop in female fertility below the age of 30, researchers in the United States and Italy said their results do not mean older couples will not be able to conceive, it just might take them longer.
"Although we noted a decline in female fertility in the late 20s, what we found was a decrease in the probability of becoming pregnant per menstrual cycle, not in the probability of eventually achieving a pregnancy," said Dr. David Dunson of the National Institute of Environmental Health Science in North Carolina.
~~~
Kindness, Intelligence Important in Mate Selection
The idea that men are interested in a woman's beauty while women are interested in the size of a man's wallet is overly simplistic, according to new study findings.
The truth is, though attractiveness and income may indeed be factors of interest, qualities such as kindness and creativity are also very important, researchers report.
--------------------------------------------------------------------------------------
Men: Breaking Up Is Bad Only if Women Do It First
When rating previous breakups, women view the process of ending of the relationship no differently if they are the dumper or the dumpee--but the same is not true with men, new research shows.
According to researchers at Francis Marion University in Florence, South Carolina, men believe there was much more scheming on the part of their partners, less finality in the relationship and less working together during the breakup if they were dumped than if they ended the relationship themselves.
For example, when rating how much scheming went into the breakup, "females don't differ much whether they were the actor or the target," Dr. Mike Jordan told Reuters Health.
"The males, on the other hand--if they're the ones who did it, they thought 'Oh, there was no plotting on my part or anything.' But there was a lot if she broke up with them," he added.
~~~
Men whose jobs involve sitting down for more than six hours a day may be reducing their chances of fathering children.
Researchers, who have designed special thermometers to fit into male underpants, found that sitting down for more than one hour led to significant increases in scrotal temperatures, something that is been linked to poorer-quality sperm.
"A high scrotal temperature is a common finding in infertile patients, and experimental studies indicate that specific types of heat exposure reduce semen quality," say the researchers.
"More and more men have a sedentary work position, which increases scrotal temperature. Normal sperm production depends on a testicular temperature below body temperature."
~~~
Soy May Help Keep Postmenopausal Arteries Healthy
A Western diet rich in tofu and other soy products may help protect older women from artery disease, new study findings suggest.
According to the report, phytoestrogens were associated with less artery stiffness among more than 400 postmenopausal women. The benefit was most pronounced among the oldest women, or those who had been postmenopausal the longest.
Arterial stiffness increases as the blood vessel disease atherosclerosis progresses, and atherosclerosis can lead to heart attack or stroke, explain researchers in the August issue of Arteriosclerosis, Thrombosis and Vascular Biology: A Journal of the American Heart Association
~~~
More Teens Lose Virginity in June
Teens are much more likely to lose their virginity during the months of June and December than at any other time of the year, a new study has found.
In general, most teens reported that if they had lost their virginity, they had done so in June. The next most popular month was December.
The analysis confirms the "summer vacation" theory for adolescent females and is now extended to adolescent males, according to the report. The seasonal effect associated with losing one's virginity was stronger in white adolescents than non-whites.
~~~
The sperm can survive for a week. The egg is more short lived.
Ovulation is 11 to 16 days after start of period.
New research shows the sperm swims towards female egg due to the egg's attraction.
~~~
DL: ideally a woman on period should have a break - if I had a partner during my period I'd leave (/he leave - we take turns).
~~~
Oral Sex Shown to Be Linked to Mouth Cancer
Although the risk is small and it is more likely to result from heavy drinking and smoking, scientists have uncovered evidence that oral sex can cause mouth cancer.
Researchers had suspected that a sexually transmitted infection that is linked to cervical cancer could also be associated with tumors in the mouth.
Now a study by researchers working for the International Agency for Research on Cancer (IARC) in Lyon, France seems to have confirmed it.
"Oral sex can lead to oral tumors," New Scientist magazine said Wednesday, referring to the latest research.
The scientists studied more than 1,600 patients from Europe, Canada, Australia, Cuba and the Sudan with oral cancer and more than 1,700 healthy people.
They found that patients with oral cancer containing a strain of the human papilloma virus (HPV) known as HPV16 were three times more likely to report having had oral sex than those without the virus strain.
Women's Brains Really Blown By Orgasms
An orgasm is literally a mind-blowing experience for a woman, scientists have revealed.
Much of her brain shuts down when she reaches a sexual climax.
The discovery was made during experiments in the Netherlands when couples' brains were scanned during lovemaking.
Neuroscientist Dr Gert Holstege, from the University of Groningen said it appeared that shutting down the brain during orgasm ensured that obstacles such as fear and stress did not get in the way.
"When you are fearful or have a very high level of anxiety, then it's hard to have sex because during sex you really have to give yourself and let go."
Men were studied in the same way but because the male orgasm typically takes such a short time it was difficult to obtain meaningful brain scan data.
~~~
In a small study, one out of three young women experienced postcoital blues at some point in their lives and 10 percent said they frequently or almost always felt sad after sex.
~~~
Sex vs. Intelligence: Bigger balls mean smaller brain
In a recent study of bats, Scott Pitnick, professor of biology at Syracuse University, found that testis size is inversely related to brain size. In other words, the bigger the balls of a bat species, the smaller its brain.
Comparing brain size and testis size for 334 species of bats, Pitnick's team looked to explore the contribution of sexual selection to brain evolution. Specifically, the research tested and confirmed two theories:
Larger testis are found in males with smaller brain size, and relative testis depends on female promiscuity.
Pitnick and his team showed that among bat species, those with promiscuous females have relatively smaller brains than species with females that are faithful to their mates. The study also found that male infidelity, by contrast, had no evolutionary impact on relative brain size.
Pitnick says a likely explanation for this relationship relates to the energetic demands of producing and maintaining both brain and sperm cells; males cannot afford a lot of both. Under this explanation, males with relatively large testes and small brains leave more offspring than larger-brained, less fertile, competitors.
“When females mate with more than one male, sperm compete to fertilize the female’s eggs. Such ‘sperm competition’ is rife in many bat species, perhaps due in part to the unusual ability (among mammals at least) of sperm to survive inside the female’s reproductive tract for a very long time,” says Pitnick. “The male who ejaculates the greatest number of sperm may win at this game, and hence many bats have evolved outrageously big testes—as much as 8.5% of their body mass. Because they live on an energetic knife-edge, bats may not be able to evolutionarily afford both big testes and big brains. We’re excited about these results, as they may stimulate more research into the correlated evolution of brains, behavior and the extravagant and costly ornaments and armaments favored by sexual selection.”
The finding is consistent with research conducted on primates.
~~~
Frequency of ejaculation according to 2 different books (they both could be wrong):
Up to ago 45: once a week
46-50: once every 1.5 weeks
51-59: once every month
over 60: never
----------
formula: age divided by 5
e.g. 40 year old: once every 8 days
~~~
WARNING: "Condoms break more often than the manufacturers like you to believe". This is what a pharmacist said.
~~~
"Because of recent findings, many condom manufacturers in the United States have stopped using nonoxynol-9 and the Centers for Disease Control and Prevention (CDC) no longer recommends using condoms with spermicide.
Use a lubricant to reduce friction and tearing during intercourse."
~~~
"Vaginal Spermicides: Advantage 24, Vaginal Contraceptive Film and other spermicides can be used for vaginal intercourse, offering some protection against unplanned pregnancy and possibly some STIs. Note: If you or your partner develop an irritation from a spermicide, stop using it. These irritations may increase your risk of getting an infection like HIV."
~~~
Here's an interesting statistic in regards to abortion. The national crime rate dropped by about 23% in the 20 years following Roe vs Wade. No big surprise there, but something that rarely gets mentioned. And for those who will claim that the drop in crime was not related to the legalization of abortion, I would point out that 5 states legalized abortion approximately 5 years before Roe v Wade and all 5 states showed a drop in crime preceding the rest of the nation. fpdoc1234
~~~
Study: Mice Sing in the Presence of Mates
Songbirds may be the Sinatras of the animal world, but male mice can carry a tune too, say Washington University researchers who were surprised by what they heard.
Scientists have known for decades that male lab mice produce high-frequency sounds — undetectable by human ears — when they pick up the scent of a female mouse. This high-pitched babble is presumably for courtship, although scientists are not certain.
But it turns out those sounds are more complex and interesting than previously thought.
"It soon became ... apparent that these vocalizations were not random twitterings but songs," said researcher Timothy Holy. "There was a pattern to them. They sounded a lot like bird songs."
~~~
Male sweat can boost arousal in women
BERKELEY, Calif. - A chemical in male sweat can boost mood, brain activity and sexual arousal in heterosexual women, according to a new study released just in time for The study offers the first direct evidence that humans secrete a scent that can affect the physiology of the opposite sex, said researchers at the University of California, Berkeley. Their findings were published this week in The Journal of Neuroscience.
~~~
sometimes a woman can have a second ovulation during her cycle. This ovulation can happen during her period so woman can get pregnant with sex during her period.
~~~
woman can have period even if she's pregnant.
~~~
machine that tests urine every morning can detect hormones as soon as they're present (5 days before ovulation).temperature test only picks up when ovulation is there and to determine when the fertile period starts it has to be guessed based on past record of number of days of cycle.
~~~
"You have a need in an evolutionary sense for both money and women. They trigger the same brain area," said Camelia Kuhnen, a Northwestern University finance professor who conducted the study with a Stanford University psychologist.
~~
Overall, those who said they had sex less than once per week were twice as likely to develop ED over the next five years as men who had sex at least once a week. Furthermore, compared with men who had sex three or more times per week, their ED risk was increased nearly four-fold.
A number of factors contribute to ED development, many of which could also affect a man's sexually activity -- such as age, diabetes and heart disease. However, after taking account of those factors, sexual activity itself remained linked to ED risk, Koskimaki's team found.
It may be a matter of "use it or lose it," according to the researchers. Just as exercise boosts physical fitness, they note, regular sexual activity may help a man preserve his erectile function.
ED occurs when there are problems with blood flow to the penis. Regular sexual activity, Koskimaki's team writes, may help maintain healthy blood vessel function in the erectile tissue.
~~~
Kissing build immune system
Writing in the journal Medical Hypotheses, researcher Dr Colin Hendrie from the University of Leeds, said: "Female inoculation with a specific male's cytomegalovirus is most efficiently achieved through mouth-to-mouth contact and saliva exchange, particularly where the flow of saliva is from the male to the typically shorter female."Kissing the same person for about six months provides the best protection, he added.As the relationships progresses and the kisses become more passionate, the woman's immunity builds up, cutting her odds of becoming ill.By the time she becomes pregnant, the odds of her unborn baby becoming infected are much lower.
~~~
"Without a doubt, a discreet anatomic entity called the G-spot does not exist," said Dr. Amichai Kilchevsky, a urology resident at Yale-New Haven Hospital in Connecticut, and lead author of the review, published Jan. 12 in the Journal of Sexual Medicine.
~~~
Also, as medical evidence suggests that men experience a significant loss of zinc with each ejaculation, eating a food high in zinc after ejaculation is recommended.
~~~
The most respected of the Tao theorist, Sun Simiao, quoted above, recommends ejaculation no more than once every 20 days for men over 50 and no more than once every 100 days for men over 60.
~~~
A research published by the US National Library of Medicine and the National Institutes of Health found that after 7 days of not ejaculating, men’s testosterone levels reached 145.7% of the baseline. The interesting thing is that they didn’t observe significant fluctuations from the baseline on days 2 through 5. The research also showed that the peak levels were at day 7