[Implantation in early abortions 18 previllous and 24 young villous oocytes (author's transl)].

The study was carried out on 42 ova that had developed to the 8th to 17th days stages inclusive and that were removed by chance when endometrial biopsy was carried out. This study shows that there were 12 normal or nearly ova and 30 pathological ones. The pathology consists of an alteration of the embryonic stock without affecting the placenta, of an embryo-placental hypoplasia and of maternal vascular troubles that lead to complete necrosis of the ovum. The risk of a defective egg is raised when the oocyte remains in the follicle for more than 14 days.