The Christian story of the birth of Jesus may be the most well-known virgin birth claim in history, but it turns out that such claims are not as rare as we might think.

A new study published in this year’s Christmas edition of the British Medical Journal has examined modern virgin birth claims, finding some interesting trends in those women who claim to have gotten pregnant while still virgins.

Researchers at the University of North Carolina looked at 7,870 women over a 14-year period who were part of the U.S. National Longitudinal Study of Adolescent Health. Of those women, 0.5% (45 of them) “consistently affirmed” that they did not become pregnant the old-fashioned way.

The women were also polled about their circumstances, home life, and sexual histories. Data about their religiosity, knowledge of birth control, and their level of sex education was collected and parsed.

The study’s authors found that the women who reported virgin births were more than twice as likely to have signed chastity pledges as those women who did not claim to have had a virgin birth. The virgin mothers were also significantly more likely to have signed chastity pledges than even other virgins who had not given birth.

Virgin mothers were, on average, younger than sexually active mothers at the time of the birth. The parents of self-professed virgin mothers were also more likely to have talked less with their child about sex and birth control.

Though these finding seem to indicate that virgin mothers on average come from sexually conservative backgrounds, the study’s authors are not jumping to the conclusion that women who claim virgin births are liars. Instead, the study is intended to give an overview of the type of women who are likely to report virgin births.