A single act of unprotected intercourse may be more likely to lead to
an unwanted pregnancy than was previously thought. The work was published
in an online edition of Human Reproduction on June
Researchers from the National Institute of Environmental Health Sciences,
in Durham, NC, studied 68 sexually active women who either had been sterilized
or were using an intrauterine device over 3 months. The women kept journals
and collected daily urine samples, which were used to identify fertile days.
Hampton T. Unplanned Pregnancies. JAMA. 2004;292(4):426. doi:10.1001/jama.292.4.426-c