Characteristics of 3,709 spontaneously menstruating^* women ages 20–49.9 in the third Nord-Trøndelag Health Study (HUNT3), Norway reporting regular or irregular menstrual cycles in the last 12 months.

<p>*Spontaneously menstruating means that they were not currently using hormone contraception.</p><p>Characteristics of 3,709 spontaneously menstruating^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134473#t001fn001" target="_blank">*</a>} women ages 20–49.9 in the third Nord-Trøndelag Health Study (HUNT3), Norway reporting regular or irregular menstrual cycles in the last 12 months.