AGUIRRE-SAMUDIO, A. J.; DE LA FUENTE-JUÁREZ, G.; MÁRQUEZ-OROZCO, A. & MÁRQUEZ-OROZCO, M. C.Correlation between function-morphology of effect of the stress and flunitrazepam administered during gestation in adult mouse ovary. Int. J. Morphol., 28(1):309-316, 2010. SUMMARY:Previously we report long lasting effects on ovary of mice prenatally exposed to flunitrazepam (FNZ), a benzodiazepine with tranquilized action. In this work we find that the FNZ don't prevent the effects on ovary prenatally exposure to stress in mice. We studied adult females born from mothers that had been stressed by immobilization on day 6 ofgestation (GD-6) or group S, and from mothers stressed also by immobilization at GD-6, but which received a single oral dose of FNZ immediately after the stress group FNZS. The control groups were the SS that received the GD-6 saline solution and the group NT non-treated. Their ovaries were extracted for histology studies and to observe the activity of 3b hydroxysteroid dehydrogenase/isomerase (3 b-HSD). The histological analysis revealed high staining affinity ovarian cell of S and FNZS. Double oocytes and apoptotic bodies were found in the secondary atretic follicles, as well as abnormal primordial, primary and secondary follicle populations, as compared to SS and NT groups. The primordial, primary, and secondary follicles were significantly reduced in the experimental groups. But the primary and secondary atretic follicles were higher in both groups, and the number of corpora lutea was lower in both groups. The activity of 3 b-HSD was abnormally increased in both FNZS-and S-groups. These findings suggest that FNZ did not counteract the impairing effects of prenatal stress on adult offspring ovarian follicles, and could rather be responsible for long lasting changes occurring during embryonic programming.