[Delayed implantation and early developmental defects in the mouse caused by PCB: 2,2'-dichlorobiphenyl (author's transl)].

Pregnant mice administered per os during the days 1--3 (plug day = day 0) post conception (p.c.) with 375 mg 2,2'-dichlorobiphenyl/kilograms/day revealed on day 18 p.c. increased number of resorptions and doses up from 500 milligrams/kilograms/day led to a substantial retardation of the prenatal development. Based on the investigations during the early development it is concluded, that retardation of the fetus is caused by a delayed implantation. It is assumed, that increased resorption is due to kyematopathies detected during the periimplantation period.