Tubal ectopic pregnancy: a histologic, morphometric, and statistical study.

Pathologists are occasionally asked for medicolegal reasons to estimate the gestational age of an ectopic pregnancy based on morphologic findings. We evaluated the correlation between the gestational age and the maximal diameter of the resected fallopian tube, the average diameter of chorionic villi, the number of chorionic villi per square millimeter of the microscopic section, the number of degenerated villi per square millimeter, the number of syncytial knots per square millimeter, and the average number of layers of cytotrophoblastic cells covering the villi. There was a significant correlation between the diameter of the fallopian tube and the gestational age, with a correlation coefficient of 0.41 and a P value of .05. There was no significant correlation of the gestational age with any of the microscopic parameters measured. The findings indicate that an approximate estimation of the gestational age of tubal ectopic pregnancies may be made using the diameter of the resected fallopian tube.