Baby!

A Surprising Rate of Virgin Births

Virgin births were reported by 0.5% of U.S. women in the National Longitudinal Study of Adolescent Health. The finding was quite a surprise to epidemiologists at the University of North Carolina at Chapel Hill. The researchers, who published their analysis in today’s issue of BMJ, at first attributed the numbers to a programming error.

But after careful analysis, they concluded that 0.8% of pregnancies  among these women — nearly one in a hundred — occurred before the women acknowledged any vaginal intercourse, and without the help of any assisted reproduction technology.

The investigators found that the women who reported virgin births differed from other women in the study. They were significantly more likely to have signed chastity pledges and to have parents who weren’t inclined to discuss sex and birth control with them. They were more likely than other virgins to claim knowledge of condom use (p<0.007) or the withdrawal method of birth control (p<0.02), but they were less likely to actually know how to use condoms (p=0.002) than non-virgins who reported pregnancy.

The authors conclude:

Even with numerous enhancements and safeguards to optimize reporting accuracy, researchers may still face challenges in the collection and analysis of self reported data on potentially sensitive topics.

On another sensitive topic — obesity — it’s worth remembering that we rely heavily on self-reported weight and dietary data. Relying on bad information is worse than confronting the gaps in our knowledge.

Click here to read more from Live Science and here to read the study in BMJ.

Baby! Photograph © Gabi Menashe / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.