Experts with sophisticated techniques can find clefts in some hymens that are consistent with the idea that a penis has been no stranger. But good luck finding the hymen that will give you proof that a penis has come calling.

It appears that the majority of sexually active women don't have clefts in their hymens, assuming you could find them if they did. More importantly, the techniques and experience to make such conclusions are way beyond the skills of the average physician, let alone the woman's boyfriend or boyfriend's mother.

Clearly, much of what we think we know about hymens is myth.

Not many of us understand the extent to which the hymen often changes at the time of puberty, give or take a few years. This change is due to the effect of estrogen on the hymenal tissue, which has estrogen receptors. As was described in the 2007 Pediatrics article quoted above, hymens that do not yet have any estrogen effects tend to be "thin, delicate membranes with relatively smooth edges." The hymens of older girls which have been effected by estrogen tend to be "thicker and more redundant and frequently had scalloped edges."

One of the reasons why hymens rarely "pop" during intercourse is because estrogen tends to make the hymen more elastic. It is as if nature anticipates that intercourse will begin shortly after puberty, and prepares the female body accordingly. Then again, there is only so much nature can do when faced with clumsy young couples and their rushed first intercourse. If there is pain from a first intercourse, it is more likely because the woman is not adequately aroused, and the furniture in her pelvis is being rearranged without the benefit of lubrication and sexual swelling that nature intended.

Unfortunately, the estrogen effect on some women's hymens is not as pronounced as on others, so there can be some hymenal stretching and pain during the first intercourse of these women. I was told by one healthcare provider who does pre-marital exams that when she discovers a young woman's hymen is not fully estrogenized, she will often suggest that the woman use a bit of estrogen cream on her hymen to help the elastization process.

As for bleeding during the first intercourse that is not related to menstruation, if it occurs it seems to be more of an indicator of what went wrong than what went right. In other words, bleeding during one's first intercourse was not part of some secret arrangement or covenant between men and nature to certify female chastity. However, I must admit, this is just conjecture since the scientific studies on bleeding during first intercourse appear to be few and far between.

There are also cases where the hymen does stretch across the vaginal opening in ways that can most certainly cause pain or bleeding, but those are the exception rather than the rule. If there is a problem of this nature, a girl might notice it when trying to insert a tampon, or more likely when trying to pull the tampon out. (This is not meant to be medical advice, and you are strongly advised to take it up with your gynecologist if you have any questions or concerns.)

As for the hymen tearing due to a non-sexual accident, an article in Pediatrics reported on two cases where girls had sustained significant genital injury while on inline skates. Each of the girls had suffered accidental "rapid-splits" injuries that resulted in genital trauma and bleeding. Yet the authors found that "None of the children from this series was noted to have any significant injuries to the hymen." (Pediatrics 2002;110;e16)

And what happens to the hymen over a woman's lifetime? Unfortunately, I know of no studies where odometers have been placed between women's legs and the wear and tear on their hymens evaluated over the long haul. So we'll have to trust the observations of gynecologists. I am posting this question on a listserve of gynecologists and women's healthcare providers that I belong to, and will report their replies to you in another week. (Follow up like this is clearly one of the perks of being a Psychology Today Blog reader!)

The reason we are now learning more about the fascinating hymen is because while the evidence for sexual abuse has often been overwhelming, examinations have shown that the hymen looked perfectly normal. To better understand this seeming contradiction, a number of studies have been done on the hymen of girls and young women in the past couple of years. The focus of these studies is on injury and abuse rather than investigating the travails of the happy hymen. So we are limited in what we can say about the hymen of a woman who has been in a loving sexual relationship.

Now--what in the blazes are surgeons doing when they perform a "hymenoplasty?" You've got me. I would have liked to have seen The Times inquire further as to what "one semicircular cut" and "10 dissolving stitches" might do in reconstructing a woman's hymen. Are they trying to make it look like the non-estrogenized hymen of an 8-year-old instead of the estrogenzied hymen of an 18-year-old? These are questions I would hope we could hear answered by gynecologists who aren't quite so financially and perhaps culturally invested in hymenoplasty.

There is still much I don't know about hymens, but this is true for me about sex in general. Even though my book is in its 5th edition and is assigned in a number of college courses, hardly a day goes by when I don't learn something new about sex.

For those of you who are interested, I did a podcast a few months ago on the hymen that can be found at ThePleasureReport.com.