[Effect of the hormonal environment on the human oocyte and its later development in vitro].

The biosynthesis of progesterone by the granulosa cells that come from follicles from which the oocyte has been fertilized and has divided in vitro is far superior to that from the cells coming from follicles in which the oocyte has failed to develop. This result is in accordance with the raised levels of progesterone and the influence of androgens on lower levels of oestrogens in follicular fluid that evolved favourably. In the same follicles the ratio of concentrations of prostaglandins PGE2 to PGF2 alpha is twice as high as in the liquid from other follicles.