Gorrindo Tristan, Lu Ying, Pincus Steve, Riley Ann, Simon James A, Singer Burton H, Weinstein Maxine
Center for Population and Health, 313 Healy Hall, Box 571197, Georgetown University, Washington, DC 20057-1197, USA.
Menopause. 2007 Jan-Feb;14(1):74-88. doi: 10.1097/01.gme.0000227853.19979.7f.
Menstrual cycles are composites of complex events; the data describing them are correspondingly rich. We seek to quantitatively represent menstrual histories from menarche to menopause and to evaluate the clinical belief that regular and stable cycle lengths are the most normative histories.
Using prospective data from the Tremin Trust, we classified the menstrual histories of 628 women as very stable (type I), stable but with greater variability in cycle lengths (type II), oscillating and erratic with a downward trend in cycle length (type III), oscillating and erratic with no downward trend in cycle length (type IV), or highly erratic and variable (type V). Classification criteria were created by examining basic summary statistics of menstrual cycle lengths. Specifically, we identified key features describing variability of median cycle length, the mean of the interquartile range, the consistency of the interquartile range, the slope of median cycle lengths, and the number of stable 5-year intervals between ages 15 and 45+.
We present the first characterization of full menstrual histories. Our taxonomy captures the essential features of menstrual bleeding patterns for a heterogeneous population. Persistently stable histories (types I and II) were seen in only 28% of the women; erratic histories (types III through V) characterized 72%. When examining all participants, significant differences were seen in age at menarche (P < 0.05), age at menopause (P < 0.01), and number of births (P < 0.01) between these stable and erratic groups.
Although clinicians have traditionally thought of "normal" menstrual histories as being regular and stable, the distribution of women in our five categories suggest that variable histories are most common. Clinically, these results may suggest the need for a paradigm shift in what gynecologists view as normal and abnormal menstrual cycle histories.
月经周期是复杂事件的组合；描述它们的数据相应地丰富。我们试图定量呈现从初潮到绝经的月经史，并评估临床观点，即规律且稳定的周期长度是最正常的月经史。
利用特雷明信托基金的前瞻性数据，我们将628名女性的月经史分类为非常稳定（I型）、稳定但周期长度变化较大（II型）、周期长度呈振荡且不稳定且有下降趋势（III型）、周期长度呈振荡且不稳定但无下降趋势（IV型）或高度不稳定且变化大（V型）。通过检查月经周期长度的基本汇总统计数据来制定分类标准。具体而言，我们确定了描述中位数周期长度变异性、四分位间距均值、四分位间距一致性、中位数周期长度斜率以及15岁至45岁以上之间稳定的5年间隔数的关键特征。
我们首次对完整月经史进行了特征描述。我们的分类法捕捉了异质人群月经出血模式的基本特征。仅有28%的女性有持续稳定的月经史（I型和II型）；不稳定的月经史（III型至V型）占72%。在检查所有参与者时，这些稳定和不稳定组之间在初潮年龄（P < 0.05）、绝经年龄（P < 0.01）和生育次数（P < 0.01）方面存在显著差异。
尽管临床医生传统上认为“正常”月经史是规律且稳定的，但我们五类女性的分布情况表明，变化的月经史最为常见。在临床上，这些结果可能表明妇科医生对正常和异常月经周期史的看法需要进行范式转变。
