Follicular atresia in relation to oocyte morphology in non-pregnant and pregnant women.

Antral follicles from normally menstruating women and women in the third trimester of pregnancy were classified as healthy or atretic by flow cytometric DNA measurements on aspirated granulosa cells and by the concentration of steroids in the follicular fluid. The oocytes contained in these follicles were characterized as healthy or degenerating by their morphology at the light microscopic level. In 98% of the cases (61/62) morphologically healthy or degenerating oocytes were found in follicles which were classified as healthy or atretic respectively. In the normally menstruating women degenerative changes in the oocyte and the remainder of the follicle appeared to occur in synchrony. In pregnant women asynchrony was noted between the oocyte and the remainder of the follicle as follicular atresia progressed. The present study demonstrated the usefulness of flow cytometric DNA measurement in characterizing antral follicles of all sizes as healthy or more or less atretic.