There is still a clear difference between ova obtained from in vivo maturation and oocytes matured in culture. Eggs obtained following the LH surge in vivo show a higher potential for development. These observations indicate that cytoplasmic competence must be different between the in vitro and the in vivo matured oocytes. Besides these functional differences, a few studies have revealed additional discrepancies between in vitro and in vivo maturation at the ultrastructure level. Differences in terms of subsequent anomalies were also observed at the chromatin level in morulae-blastocysts obtained with either procedure. There are two possible explanations for the differences observed: the culture conditions used or the initial intrinsic competence of the oocyte. It is certainly feasible to improve the culture conditions during maturation, but after 10 years of collective efforts, it seems that a specific signal or component is missing rather than inadequate or toxic culture conditions. If the immature oocytes possess differing degrees of competence, these might be due to factors affecting the oocyte during late folliculogenesis. Different follicular conditions would lead to differing oocyte competence. The origins of the oocytes are discussed with respect to five different aspects: cumulus morphology, follicular size, follicular health, ovarian stimulation and the oocyte handling procedure before the beginning of incubation. Our results, in addition to the evidence from the literature, suggest that the oocyte enters a permissive state when obtained from large and differentiated follicles as in dominance, early atresia or near ovulation. Developmental competence can then be induced by either LH in vivo or mimicked by an exposure of the ovary to warm incubation conditions for a few hours before collecting the oocytes. The increased development obtained in these conditions suggest that the ability to continue to the blastocyst stage is acquired in the follicle.