Even when using 10-fold magnification, doctors can not accurately sort virgins from the sexually-active, several studies have reported.

Axar.az reports citing Livescience.

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.