Early pregnancy wastage: relationship between chorionic vascularization and embryonic development.

The chorionic villous vascularization of 40 patients with first trimester spontaneous abortion was compared with that of 10 patients undergoing legal abortion (control group). The spontaneous abortion group was subdivided into a group with intrauterine embryonic death (n = 20) and a group with blighted ova (n = 20). Villous vascularization appeared unaffected after prolonged postmortem intrauterine retention. The incidence of vascularized villi was 89% in the control group, 26% in the group with embryonic death, and 9% in the group with blighted ova. In addition, the vascular density of vascularized villi was three to four times higher in the control group than in the two spontaneous abortion groups. The present study provides evidence that, in case of embryonic death and blighted ova, chorionic villous vascularization is deficient.