The objective of our work was to study the effect of parity the parity of the does, the intra uterine position and vascularization of the fetuses and their number per horn on, available uterine space and placentae development in the rabbit at two stages (nulliparous and primiparous). To this aim, twenty rabbit does of locally Algerian population were distributed in two groups of 10 each (nulliparous and primiparous). The does were mated and slaughtered on 24 th day of gestation. In the group of

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... fetuses receiving poor blood supply (≤ 4 blood vessels), the individual weight and the crown-rump were lower (-24.4 and -12.6% respectively; p < 0.05) compared to those with higher number of blood vessels (≥ 5). The intra uterine position affects significantly the individual weight of maternal placenta and the heavier one was located in the oviduct. Significant interaction between parity and the number of blood vessels was recorded for the individual weight of fetal placenta (p < 0.05). Available uterine space was lower in the primiparous, in the middle position and in the class of fetuses with lower blood supply. In primiparous, the horns with 5 or 6 fetuses presented a better vascularization than those with the same number in nulliparous (+25%). The fetal weight and crown-rump decreased when the number of fetus per horn increased (p<0.05). A significant interaction was recorded between the parity and the number of fetus per horn for the weight of maternal placenta (+ 15% and + 30% respectively in the horn within 3 or 5 fetuses in nulliparous; p < 0.05). Available uterine space was greater in nulliparous compared to the primiparous and decreased when the number of fetus per horn increased. These results suggest that available uterine space and fetal development at 24 th of pregnancy are affected respectively by parity of the rabbit and the vascularization of the implantation site.