Correlation between histologic dating of human corpus luteum and the luteinizing hormone peak--biopsy interval

The purpose of this study was to assess the accuracy of retrospective dating of ovulation in women based on the histologic dating of the corpus luteum. Corpora lutea enucleated from the ovary of 39 women between one and six days following the LH peak in plasma were examined by routine histologic techniques and dated according to Corner's criteria. The correlation between the luteinizing hormone (LH) peak--biopsy interval and histologic dating was assessed. Linear regression analysis of the data gave a correlation coefficient of 0.76. However, the dating of different corpora lutea obtained at the same LH peak--biopsy interval can differ by as much as four days. In addition, it was found that the stages named by Corner as days 1 and 2 seem to develop within the first 24 hours following the LH peak, while stages corresponding to days 4 and 5 each take two days to develop. It is concluded that the use of corpus luteum morphologic features for retrospective timing of ovulation is subject to an error of variable magnitude due to unequal duration of each stage, as well as considerable individual variation.