As we have seen, scholars tend to place the Conception Nostre Dame relatively early in the poet's career, before his Vie de saint Nicolas. The main reason for this is that in the Nicolas the reader can more readily discern the Wace of the Roman de Brut, whereas (to put things bluntly) the Conception was not considered to be very good literature. The first editors of the poem, G. Mancel and G.-S. Trébutien (1842), despite their more favourable opinion of Wace than many of their contemporaries, felt that he had not made the best use of his sources in this case; according to them the poet

William R. Ashford, in his 1932 critical edition of the Conception, is especially damning: ‘The Conception de Nostre Dame has little literary merit. Its interest for modern students is almost wholly linguistic’ (p. 20). This appears to reflect Ashford's own interest in philology above literary analysis, however; whilst the observations of Mancel and Trébutien alert us to the extent of Wace's reworking of his sources, suggesting hidden depths to the poem.

The Conception Nostre Dame is (notwithstanding the title by which the poem is now known) a Life of the Virgin from her Conception to her Dormition and Assumption. The sources on which the work is based were mainstream by medieval standards, though they were not part of the canonical corpus of Scriptures. The De nativitate Mariae, a hybrid text combining a variety of earlier apocryphal material and dating from the Carolingian period (or possibly as late as the tenth century) was used for the section devoted to the conception and birth of Mary, her own pregnancy and Joseph's misgivings. The story of the three Marys was drawn from a version of the Gospel of Pseudo-Matthew (composed in Latin between 550 and 700), the Trinubium Annae, known to have been in circulation from the ninth century and recounting the three marriages of Saint Anne (mother of the Virgin), the three daughters, all named Mary, she had of each marriage, and the offspring of these daughters, among whom it counts St John the Evangelist.